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Component Maintenance Manual With Illustrated Parts List For Nickel-Cadmium Battery Type SP-138 Part Number 30475-002

MarathonNorco Aerospace, Inc. P.O. Box 8233 Waco TX. 76714-8233 Phone: (254) 776-0650

8301 Imperial Drive Waco, TX. 76712-6588 Fax: (254) 776-6558

E-Mail: [email protected] Website: www.mnaerospace.com

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RECORD OF REVISIONS Original Issue Date: JAN 01/89 Rev No. 1 2 3 4 5

Issue Date 06/30/01 03/15/03 11/30/03 05/07/04 03/27/08

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LIST OF EFFECTIVE PAGES SUBJECT

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Record of Temp Revisions

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Service Bulletin List

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Table of Contents

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Introduction

INTRO-1 INTRO-2 INTRO-3 INTRO-4 INTRO-5 INTRO-6

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Description and Operation

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Testing and Fault Isolation

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Disassembly

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Cleaning

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Check / Inspection

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Repair

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Assembly (Including Storage)

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Special Tools, Fixtures and Equipment

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Illustrated Parts List

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TABLE OF CONTENTS SUBJECT

PAGE INTRO-1

Introduction Description and Operation

1

Testing and Fault Isolation

101

Disassembly

301

Cleaning

401

Check / Inspection

501

Repair

601

Assembly (Including Storage)

701

Special Tools, Fixtures and Equipment

901

Illustrated Parts List

1001

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INTRODUCTION

This manual contains shop verified instructions for maintenance and an illustrated list of component parts for the nickel-cadmium battery, type SP-138 and its cell, type 38SP100. These instructions are grouped in topics shown in the Table of Contents. They are for the operation, testing, repair and overhaul of the battery.

WARNING: SERIOUS INJURY CAN RESULT FROM CARELESSNESS WHILE HANDLING AND WORKING WITH NICKEL-CADMIUM BATTERIES. PLEASE OBSERVE THE FOLLOWING SAFETY RULES WHILE WORKING WITH THESE BATTERIES.

1. Remove all metal articles such as bracelets and rings. 2. Metal tools must be insulated. 3. Wear protective clothing and eyeware. The electrolyte can cause burns if in contact with skin. 4. Do not smoke or hold naked lights near batteries on charge. These batteries give off a mixture of oxygen and hydrogen during charge which, if allowed to accumulate in a confined space, could cause an explosion. Do not charge the battery on the bench with the cover on. 5. Do not mix lead-acid and nickel-cadmium battery servicing. 6. Do not use petroleum spirits, trichloroethylene or other solvents.

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DEFINITIONS OF COMMONLY USED BATTERY TERMS Ampere-Hours A unit of electrical measurement generally used to describe the capacity of a cell or battery. The product of discharge current (in amperes) x the time of discharge (in hours), it is also used to describe the amount of electrical energy put back into a battery during the charging process. Abbreviated as Ah or Amp. Hrs. Battery One of the sources of direct current (D.C.) power; a device that converts stored chemical energy directly into electrical energy (electricity). Strictly speaking, a battery consists of two or more cells connected to form one unit. Through common usage, the terms “battery” and “cell” are now used interchangeably so that a battery may refer to one or more cells. Cadmium Electrode—See Negative Plate Can The battery box which contains the cells, associated intercell connectors, hardware and sometimes electrical devices. Capacity A measure of the stored electrical energy that is available from a fully charged battery. Generally expressed in Ah. Cell As used in the battery industry, it is a device which contains positive and negative polarity plates, separator and electrolyte. Enclosed in a cell case and fitted with terminals, it is the basic building block of the battery.

Charge Efficiency The ratio of the ampere-hour capacity removed from a battery to the number of ampere-hours put into the battery during charge. Usually expressed as a percentage. Ah Output Ah Input X 100 Charge Retention The amount of capacity retained (or deliverable) by a fully charged battery after it has been stored for a stated period of time. Sometimes called shelf life. Charging The process of supplying electrical energy to a rechargeable battery for the purpose of converting its contents to stored chemical energy in which form it is again ready for use. Closed Circuit Voltage The instantaneous voltage of a cell or battery when a load is first applied. Constant Current Charging A method used to charge a battery in which a predetermined, fixed current is passed through it. See also charging. Constant Potential Charging Sometimes called constant voltage charging, this refers to a method in which a fixed voltage source is applied across the battery terminals. The charge current is variable and depends primarily upon the difference in voltage between the voltage source and that of the battery. The initial charge current is high and decreases as the battery accepts the charge.

Cell Puller A specially designed tool used to facilitate the removal of cells from a battery.

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“C” Rate That discharge rate, in amperes, at which a battery or cell will yield its capacity to a 1.0 volt per cell endpoint in one hour. Fractions or multiples of the C rate are also used. C/5 refers to the rate at which a battery will discharge its capacity in 5 hours; 2C is twice the C rate or that rate at which a battery will discharge its capacity in about 1/2 hour. Example: a 25 Ah battery will have a C rate of 25 amperes, a C/5 rate of 5 amperes and a 2C rate of 50 amperes. This rating system helps to compare the performance of different sizes of cells and batteries.

End-of-Charge Voltage The voltage of a battery at the conclusion of a charge measured while the battery is still on charge. Endpoint (or End) Voltage Voltage at which a charge or discharge is normally terminated. Equalization—See Reconditioning Fading The loss of capacity that occurs when a battery is cycled using constant potential charging.

Cut-Off Voltage—See Endpoint Voltage Cycle One charge-discharge sequence on a rechargeable battery. Discharge Current (or Rate) The magnitude of current removed from a battery, usually expressed in Amperes (Amps. or A) or Millamperes (mA); sometimes expressed in terms of “C” rate. Discharging The removal of electrical energy from a battery. Electrodes Poles (or plates) of a cell at which the electrochemical reactions occur and through which current flows. Electrolyte A conductive medium that provides for the movement of ions (current flow) between the positive and negative plates of a cell; an alkaline solution in nickel-cadmium cells. See also Potassium Hydroxide.

Final Charge Voltage—See End-of-Charge Voltage. Intercell Connectors An electrically conductive bar or strap which connects together individual cells in a battery; in nickel-cadmium batteries, usually made from, nickel plated steel, or nickel plated copper. Life The duration of satisfactory performance of a battery, measured as the number of chargedischarge cycles; sometimes measured as years of usage. Maintenance The procedures required to keep a battery in a usable condition. These include inspections, cleaning, reconditioning, and periodic water additions to the electrolyte. Negative Plate The plate from which electrons flow, through the external circuit when the battery is discharging. In the nickel-cadmium battery, it is the plate that contains cadmium which is oxidized during discharge.

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Nominal Voltage The voltage of a fully charged cell or battery while delivering current. The nominal voltage of a nickel-cadmium battery cell is 1.2 volts. Open Circuit Voltage The voltage of a battery at rest, that is, with no charge or discharge current flowing. Overcharging Continuing the charge after replacing the Ah of capacity that had been removed previously. Overcharging is required in order to make up for the inefficiency of charge. It is sometimes used to keep a battery in a “ready” condition. During overcharge, the vented nickelcadmium cell will evolve hydrogen and oxygen resulting from the decomposition of the water in the electrolyte. The evolved gas is proportional to the overcharge current.

chemically reduced to a lower oxidation state during discharge. Potassium Hydroxide A chemical compound which is mixed with pure water in exact proportions to form the electrolyte used in nickel-cadmium cells. Rated Capacity The number of Ah that a battery is capable of delivering when fully charged and under specified conditions of rate of discharge, temperature and end-point voltage. Sometimes also expressed in watt-hours. Rechargeable Battery A battery that chemically stores electrical energy and is capable of cyclic delivery and restoration of the energy through the utilization of reversible chemical reactions.

Oxidation The release of electrons by the cell’s active material—as by the cadmium at the negative plate—to the external circuit during a discharge.

Reconditioning A procedure consisting of a deep discharge and a constant current charge that is used to correct a cell imbalance that may occur during continual use of a rechargeable battery.

Plate One of the two-cell components at which the electrochemical reactions take place and in which chemical energy is stored. See Positive Plate and Negative Plate.

Reversal In a rechargeable battery, this refers to a change in the normal polarity of the cell or battery to the opposite polarity as when a cell is driven into reverse during a deep discharge, or, when a cell or battery is inadvertently charged in reverse.

Plateau Voltage The closed circuit voltage observed on the relatively flat portion of a discharge curve. Positive Electrode—See Positive Plate Positive Plate The plate to which electrons flow through the external circuit when the battery is discharging. In the nickel-cadmium battery, it is the plate that contains nickel oxide which is

Separator A material that is used to prevent metallic contact between the positive and negative plates in a cell. Vented nickel-cadmium cells also contain a gas barrier to prevent the gas (oxygen) produced at the positive plate during overcharging from reaching the negative plate which it would tend to discharge.

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Shorting Clip A short length of wire (with or without a low value resistor), or a metal spring, used to “short” a cell to zero volts. State of Charge The amount of stored energy (capacity) available in a rechargeable battery. Usually expressed as a percentage of its full capacity. Terminals The positive and negative parts of a cell through which external connections are made to the plates. Trickle Charge A continuous constant current, low-rate charge (slightly more than the self-discharge rate) suitable to maintain a battery in a fully charged condition. Vent Plug A normally sealed device which allows the controlled venting of gases from a cell while preventing electrolyte leakage. The vent plug is removed when electrolyte level adjustments must be made. Vented Cell A rechargeable cell which employs a vent plug to permit gases to be expelled during overcharge; sometimes also called a “flooded cell” because of the volume of electrolyte used in the cell. Voltage The difference in potential measured between the two electrodes of a cell or battery and expressed in units of volts.

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DESCRIPTION AND OPERATION

DESCRIPTION The SP-138 battery consists of eleven nickel-cadmium cells, type 38SP100, enclosed in a cold-rolled steel fluidized bed epoxy coated container. The battery is designed to be used for standby/busbar support and auxiliary power starting. Two Battery units are required for aircraft operation. NOTE: The cell assembly contains a vent/filler cap which incorporates a visual liquid level indicator for checking the low level limit of the electrolyte. Nominal Voltage: Rated Capacity: Electrical Receptacle: Electrolyte: Overall Dimensions: Weight:

14 Volts 38 Ampere Hours at One Hour Rate Type BR-8 (MS-3509) KOH S.G. 1.30 10.75 x 9.25 x 12 High 46 lbs.

GENERAL The nickel-cadmium battery cell is an electrochemical system in which the active materials contained in the plates undergo changes in oxidation state with little or no change in physical state. These active materials do not dissolve in the alkaline (potassium hydroxide) electrolyte while going through the changes in oxidation state. As a result the electrodes are very long-lived. In common with many of the other battery systems, some of the electrochemical mechanisms involved in the charge, discharge, and storage of the nickel-cadmium battery cell are rather complex. This is especially true of the positive (nickel hydroxide) plate. However, a brief, simplified account of the essential reactions is offered here in order to help initiate the reader into the theory and principles of this system and thus further his understanding of the operation of the battery and the role played by its main components.

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OPERATION VOLTAGE AND CAPACITY The open circuit voltage of a vented nickel-cadmium battery cell is generally accepted as 1.28 volts. (The open circuit voltage of a battery would be 1.28 volts times the number of cells in the battery.) This value is the same regardless of the size or shape of the cell although it does depend upon such factors as the temperature of the cell and the elapsed time since its last charge. Immediately after removal from a charger, the voltage is higher (above 1.40 volts) but slowly settles and maintains a value of about 1.35 to 1.28 volts per cell. The open circuit voltage does not indicate the state of charge. The nominal voltage of a vented nickel-cadmium battery cell is usually accepted as 1.20 volts. This voltage or greater is normally maintained throughout the discharge period until about 80% of the 2hour rated capacity has been removed from the cell. When discharged at significantly higher rates or temperatures other than normal room temperature, the cell’s voltage will fall below 1.20 volts more rapidly. The closed circuit voltage of a vented nickel-cadmium battery cell is that voltage read immediately after a load is connected and is something less than its open circuit voltage. It is highly dependent upon such factors as length of stand time subsequent to charging, the magnitude of the discharge current, and battery temperature. Typically, it would be about 1.25 volts when measured at the 1hour rate at 750-800F; at the 5-hour rate it would be about 1.28 volts. The working voltage or plateau voltage is that voltage observed on the level plateau of the discharge curve of a nickel-cadmium battery cell when the cells’ voltage is plotted against time. This value generally averages 1.22 volts and ranges from 1.15 to 1.25 volts again depending upon the stand time, discharge current, and battery temperature. The end-of-charge voltage, measured while the cell is on charge, depends upon its temperature and the method used for charging it. As an example, a cell in a 22-cell battery being charged at room temperature at 33.0 volt constant voltage would read about 1.5 volts at the end of charge; at a 31.9 volt constant voltage condition, the cell would read about 1.45 volts. Under constant current charging conditions, this value would depend upon temperature and charge current. Capacity is a measure of the stored electrical energy, generally expressed in ampere-hours, that is available for use from a fully charged battery.

CHARGE Charging results in the conversion of electrical energy to stored chemical energy.

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OVERCHARGE Continued charging after full chemical conversion. Overcharge beyond nameplate capacity is required to obtain maximum battery capacity.

DISCHARGE Discharging results in the conversion of the chemical energy stored in the cell to electrical energy.

OVERDISCHARGE A cell which has been driven into a region where its voltage has become negative is said to have been over-discharged (also known as cell reversal). In such a cell, the positive plate assumes a negative polarity and the negative plate assumes a positive polarity. Under extreme discharge conditions, negative voltages have been observed. The effect of such reversal is the occurrence of vigorous gassing. Long term high rate overdischarges may cause particles to break away from the plates. This could result in a permanent loss of capacity or cause an internal short. There appears to be no long-term effects of occasional cell reversal at low-to-medium rates.

Factors Affecting Capacity Capacity is measured quantitatively in ampere-hours at a specified discharge rate to a specified cutoff voltage usually at room temperature. The cut-off voltage is generally figured as 1.0 volt per cell, but varies with the discharge rate and temperature. At higher rates and low temperatures, the cut-off voltage is sometimes calculated as 0.6 volt per cell while at lower rates and/or higher temperatures a cut-off voltage of about 1.1 volts is used. Battery capacity depends upon several factors including such items as: 1. 2. 3. 4.

Cell design (cell geometry, plate thickness, hardware, and thermal design govern performance under specific usage conditions of temperature, discharge rate, etc.). Discharge rate (high current rates yield less capacity than low rates.). Temperature. Charge rate (higher charge rates generally yield greater capacity).

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Before Charging Perform necessary inspection, cleaning, repair, and torque check on intercell connector hardware before charging.

Charging Precautions and Notes CAUTION: REMOVE ALL SHORTING DEVICES FROM THE BATTERY TERMINALS AND CELLS BEFORE CONNECTING THE CHARGER CABLE.

Charge Batteries in an Upright Position Inversion of batteries during the final stages of charge may cause excessive loss of electrolyte.

Use Correct Polarity Reverse charging at high rates may damage the battery. Before starting the charge, make sure that the battery is connected correctly to the charging source—the positive terminal of the charger output to the positive terminal of the battery; the negative terminal of the charger to the negative terminal of the battery. Generally the red lead on the charging source is positive; the positive terminal of the battery is indicated by a plus sign.

Charge Method It will be necessary to charge the battery prior to putting it into service. Marathon recommends a two step constant current charging profile or charging with an RF-80K Reflex Charger. (See Battery Charging section of this manual.)

Adjust Charge Controls The charge voltage or charge current on the charging source should be set at zero before throwing the switch. Then slowly adjust the voltage or current level to the required value. Otherwise, too high a current may cause a partially charged battery to gas violently and spew electrolyte.

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Avoid Short Circuits A Nickel-cadmium battery can produce tremendous surges of power on being short circuited. This should be avoided especially on charged or partially charged batteries. In any event, care should be exercised when working with the battery. Do not drop tools or other metallic objects onto the intercell connectors, severe arcing will result with possible injury to personnel and damage to the battery. Only insulated tools should be used for servicing nickel-cadmium batteries. Rings, metal watch bands or other metallic jewelry should be removed before working around the battery. Should such metallic objects contact intercell connectors of opposing polarity, they may fuse themselves to the connectors and cause severe skin burns.

CHARGING INFORMATION Charging Individual Cells Exercise care when charging individual cells outside of the battery can. Gas pressure developed during the charge and overcharge of an unsupported cell may crack the cell case and cause injury to personnel; always support the wide faces of the cell. To simulate battery assembly, a special frame may be fabricated to fit the cell, or two plates may be placed on each wide face of the cell (or several cells connected in series) and held together by a C-Clamp.

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BATTERY CHARGING Constant Current Constant current charging refers to a method in which the charger maintains a predetermined and constant current throughout the charge and overcharge intervals. It is the preferred method of charging and is very effective in maintaining cell balance and full capacity. The constant current charging method is generally used in battery maintenance shops because of its simple current design, its relatively low current carrying, low cost components, and ease of operation and regulation.

Reflex Mode Reflex charging refers to charging with a Christie RF80K battery charger. This device applies a negative current pulse (discharge) to the battery as it approaches full charge. The effect is to minimize gas bubble formation and to improve charge acceptance for the battery. Marathon recommends a two step charge profile consisting of one hour of Reflex charging at the 2C rate plus 2 hours of constant current charging at one C/5rate.

WATER LOSS As the battery approaches the end of charge and during overcharge, gassing occurs. The gassing results chiefly from the electrolysis of the water component of the electrolyte and makes necessary the periodic inspection of the electrolyte level in cells and the addition of water when it falls below a certain recommended level.

Adjustment of Electrolyte Water additions to adjust the liquid level are made within the last 15 minutes of the topping charge using the green leveling tool supplied in Marathon Kit 32480-001. NOTES: Make electrolyte adjustments with distilled, deionized, or demineralized water only. Do not use tap water.

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TESTING AND FAULT ISOLATION Maintenance and Reconditioning Schedules At no time should a battery be allowed to deteriorate to a point where its performance affects the mission or the operation of the aircraft. A proper maintenance program is required to prevent battery failures. Such a program requires trained, knowledgeable personnel familiar with proper battery maintenance and reconditioning procedures and the keeping of accurate records. Depending upon: a) type of starting service; b) battery duty cycle; c) operating temperature; and d) charger voltage regulator setting, flight hours are the main factor in determining the frequency of water additions and reconditioning cycles. Because of the widely varied flight profiles encountered in individual aircraft use, no fixed maintenance and reconditioning period can be specified. These periods can only be approximated. The user must eventually apply his experience and the information gained during the first few maintenance and reconditioning periods to determine the schedule that is best suited to his particular type of battery usage.

Reconditioning Nickel-Cadmium Batteries

Importance of Reconditioning Under certain conditions of use, nickel-cadmium batteries may show a temporary loss of capacity. Usually this loss is due to an imbalance in individual cell capacities as may result from differences in self discharge rates, charge efficiency, etc. Reconditioning is recommended to restore a battery to its full capacity and to prevent premature damage and failure. The data obtained during the reconditioning of a battery is invaluable for determining the maximum flight hours between reconditioning services. In aircraft where more than one battery is used, either in series or parallel starting. Perform the conditioning service on both batteries during the same inspection period.

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Reconditioning Procedure A battery may be received in the service shop in an unknown state of charge. The cells may look as if they are dry and need water. It may be a discharged battery or one that has been allowed to run dry. In any case, proceed as follows: 1. Inspect the battery per instructions on Page 501. If necessary, clean the battery (refer to Page 401). 2. Perform an electrical leak check. This refers to the external electrical leakage between a cell terminal or connector and the battery can caused by electrolyte collecting around the cells usually as a result of spewing from the vent caps. It may also be caused by a damaged cell caseto-cover seal. A leakage path greater than about 50 milliamperes between the battery can and either positive or negative terminals of the battery is considered to be excessive. NOTE: Do not use the voltage reading between the terminals and the battery as a criteria for rejection; current flow is the determining factor.

CAUTION: DEPENDING UPON CONDITIONS, A POTENTIAL SHOCK HAZARD MAY EXIST ACROSS EITHER BATTERY TERMINAL AND THE CAN ON A BATTERY ASSEMBLY HAVING A VOLTAGE OF 50 VOLTS OR GREATER AND A LEAKAGE CURRENT GREATER THAN 2 MILLIAMPERES. KEEPING THE LEAKAGE CURRENT BELOW 2 MILLIAMPERES BY THOROUGH CLEANING AND INCREASED MAINTENANCE WILL REDUCE OR ELIMINATE THIS POTENTIAL SHOCK HAZARD.

Procedure A. To determine if external leakage is of such a magnitude as to require a complete battery cleaning, set the range selector of a multimeter to the 500 milliampere range or higher. B. Place the positive lead of the meter on the positive terminal of the battery receptacle and momentarily touch the negative lead of the meter to any exposed metal on the battery can. NOTE: Most Marathon batteries are supplied with epoxy coated battery cans and covers - in order to completely insulate the cells from the can. Where epoxy cans are used, current flow may be measured between the battery terminals and the screws that are used to mount the main connector. C. If the needle deflection is within the meter limits, connect the negative lead of the meter to the battery can. Now, decrease the meter current range until the current, if any current flow exists, is readable. Record this current value.

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D. Repeat the above, connecting the negative lead of the meter on the negative terminal of the battery receptacle and the positive meter lead to any exposed metal on the battery can. E. If either of the above current measurements exceed 50 milliamperes, flush the tops of the cells and dry as on Page 401. F. Repeat the above current test on both positive and negative terminals. If the tops of the cells are cleaned properly and the current measurement is still greater than 50 milliamperes, one or more of the cells may be leaking. To isolate this cell or cells, proceed as follows: (1)

Using a voltmeter of 1000 ohms-per-volt or greater, place one of the meter leads on either the negative or positive terminals of the battery and the other lead on any exposed metal of the battery can; note the meter reading. If the meter reads left of zero, reverse the positions of the meter leads.

(2)

Keep one meter lead on the exposed metal surface of the can and move the other lead systematically from one cell terminal to another, noting the voltage readings. Voltage readings will decrease and finally go negative indicating the location of the path and possibly a leaky cell.

(3)

If the cell is leaking, replace the cell or cells following the procedure described on Page 301. If no leaking cells are found, the leakage path may be due to electrolyte along the outside of the cells and at the bottom of the battery can: proceed as on Page 401.

3. Charge: Charge the two batteries connected in series on a constant current charger at 21 amps for 2 ½ hours. Reduce the rate to 7.6 amps and continue to charge for 2 hours. During the last 15 minutes of the 7.6 amp charge, adjust the electrolyte level using deionized water and the green syringe tip in Marathon kit 32480-001 Alternately, the Christie RF80K may be used for the main charge. Set the charger to 22 cells and 80 amps (2C). Charge for 1 hour, and then complete the charge at 7.6 amps per step 3. 4. Discharge: The battery is now ready for discharge. Discharge it at 38 amps (1 hour rate) to an average voltage of 1.0 volt per cell (22 volts for a 22 cell battery) and record the time. A. If the discharge capacity is more than 85% of the 1 hour rate (i.e., 51 minutes, or 32.3 amp hours), the battery has passed the capacity test and may be prepared for return to service. Recharge as in Step 6 below. B. If the discharge capacity is less than 51 minutes, the battery has failed the capacity test and a supplemental (deep cycle) discharge must be performed as in Step 5 below, followed by another cycle of charge and discharge as in Steps 3 & 4, and another charge as in Step 6.

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5. Deep Cycling: Continue the above discharge. As each individual cell reaches 0.5 volts or less, place a metal shorting clip (Figure 903) across its terminal while the load is still applied. Continue until all cells are shorted. Allow the battery to remain shorted for at least 4 hours, preferably overnight. 6. Recharge: Recharge the battery per step 3, above. A. During the final 5 minutes of charge, read the voltage of each individual cell. For automatic chargers that have terminated, reset the charge 10 additional minutes and read the voltage of each cell at the end of this time (with current flowing). The minimum voltage should be 1.55 volts per cell and the maximum 1.75 volts per cell at room temperature (70 0F-800F). If any cell fails to rise to the minimum voltage specified, the charge should be continued for an additional hour. At this time, with current flowing, read the voltage of each cell again. B. Any cell that fails to rise to 1.55 volts or peaks above these voltages, then decreases below 1.50 volts must be removed from the battery. Any cell whose voltage rises above 1.75 volts should also be removed. C. If three or more cells are found to be defective, either at one time or over a period of time, it is recommended that all the cells in the battery be replaced because the probability is great that the remaining cells have also been damaged and will shortly have to be replaced. D. If the battery has passed all of the requirements of Steps 1 through 6 above, the battery is ready for installation or storage. TROUBLE 1. APPARENT LOSS OF CAPACITY

2. COMPLETE FAILURE TO OPERATE

PROBABLE CAUSE

CORRECTIVE ACTION

Very common when recharging across constant potential bus, as in aircraft – usually indicates imbalance between cells because of difference in temperature, charge efficiency, self-discharge rate, etc., in the cells.

PERIODIC RECONDITIONING WILL HELP ALLEVIATE THIS CONDITION.

Electrolyte level too low. Battery not fully charged.

CHARGE AS IN STEP 3. ADJUST ELECTROLYTE LEVEL AND CHECK CAPACITY AS IN STEP 4. CHECK CHARGING SYSTEM.

Defective connection in equipment circuitry in which battery is installed – such as broken lead, inoperative relay or improper receptacle installation.

CHECK AND CORRECT EXTERNAL CIRCUITRY.

End terminal connector loose or disengaged. Poor intercell connections.

CLEAN AND RETIGHTEN HARDWARE USING PROPER TORQUE VALUES.

Open circuited or dry cell.

REPLACE DEFECTIVE CELL.

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TROUBLE 3.EXCESSIVE SPEWAGE OF ELECTROLYTE

PROBABLE CAUSE

CORRECTIVE ACTION

High charge voltage. High temperature during charge. Electrolyte level too high.

CLEAN BATTERY, CHARGE AND ADJUST ELECTROLYTE LEVEL.

Loose or damaged vent cap.

CLEAN BATTERY, TIGHTEN OR REPLACE CAP, CHARGE AND ADJUST ELECTROLYTE LEVEL.

Damaged cell and seal.

SHORT OUT ALL CELLS TO 0 VOLTS, CLEAN BATTERY, REPLACE DEFECTIVE CELL, CHARGE AND ADJUST ELECTROLYTE LEVEL.

4. FAILURE OF ONE OR MORE CELLS TO RISE TO THE REQUIRED 1.55 VOLTS AT THE END OF CHARGE.

Negative Electrode not fully charged.

CHARGE BATTERY AS IN STEP 3. IF THE CELL STILL FAILS TO RISE TO 1.55 VOLTS OR IF THE CELLS’ VOLTAGE RISES TO 1.55 VOLTS OR ABOVE AND THEN DROPS BY 0.05 VOLTS MORE, REMOVE CELL AND REPLACE.

5. DISTORTION OF CELL CASE AND COVER

Overcharged, overdischarged, or overheated cell with internal short.

DISCHARGE BATTERY AND DISASSEMBLE, REPLACE DEFECTIVE CELL. RECONDITION BATTERY.

Plugged vent cap. Overheated battery.

REPLACE VENT CAP CHECK CHARGER VOLTAGE, TREAT BATTERY AS ABOVE, REPLACING BATTERY CASE AND COVER AND ALL OTHER DEFECTIVE PARTS.

6. FOREIGN MATERIAL WITHIN THE CELL CASE

Introduced into cell through addition of impure water or water contaminated with acid.

DISCHARGE BATTERY AND DISASSEMBLE, REMOVE CELL AND REPLACE, RECONDITION BATTERY.

7. PARTICLES OF PLATE MATERIAL

Too high a concentration of electrolyte caused by adding potassium hydroxide raising the specific gravity.

PROCEED AS IN 6.

8. FREQUENT ADDITION OF WATER

Cell out of balance.

RECONDITION BATTERY.

Damaged “O” ring, vent cap. Leaking cell.

REPLACE DAMAGED PARTS. DISCHARGE BATTERY AND DISASSEMBLE, REPLACE DEFECTIVE CELL, RECONDITION BATTERY.

Charge voltage too high.

ADJUST CHARGING VOLTAGE.

9. CORROSION OF TOP HARDWARE

Acid fumes or spray or other corrosive atmosphere.

REPLACE PARTS. BATTERY SHOULD BE KEPT CLEAN AND KEPT AWAY FROM SUCH ENVIRONMENTS.

10. DISCOLORED OR

Dirty connections.

CLEAN PARTS AND REPLACE IF

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TROUBLE BURNED END CONNECTORS OR INTERCELL CONNECTORS

PROBABLE CAUSE

CORRECTIVE ACTION

Loose connection. Improper mating of parts.

NECESSARY, RETIGHTEN HARDWARE USING PROPER TORQUE VALUES. CHECK TO SEE THAT PARTS ARE PROPERLY MATED.

11. DISTORTION OF BATTERY CASE AND/OR COVER

Explosion caused by: Dry cells Charger failure High charge voltage Plugged vent caps Loose intercell connectors

DISCHARGE BATTERY AND DISASSEMBLE, REPLACE DAMAGED PARTS AND RECONDITION.

12. CELL TO BATTERY CAN LEAKAGE TO GROUND DETECTED BY TESTING AS ON PAGE 102.

Excessive spewage.

CLEAN BATTERY, CHARGE AS IN STEP 3, AND ADJUST ELECTROLYTE LEVEL. RECHECK FOR ELECTRICAL LEAKAGE.

Damaged cell case to cover seal.

DISCHARGE BATTERY AND DISASSEMBLE, REPLACE DEFECTIVE CELL, RECONDITION BATTERY.

13. FOAMING OF ELECTROLYTE DURING CHARGE

Contaminant in electrolyte.

DISCHARGE BATTERY AND REPLACE DEFECTIVE CELL.

Apparent low electrolyte concentration following addition of water.

RECONDITION BATTERY, REPLACE CELL THAT CONTINUES TO FOAM.

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MarathonNorco Aerospace, Inc. COMPONENT MAINTENANCE MANUAL P/N 30475-002 BATTERY SERVICE DATA SHEET

File of

Page Work Order

Aircraft Type

Date

Aircraft No.

Battery S/N

Hours in Service

Battery Type

Service Performed by

Specifications

Main Chg. Amps

Top Chg. Amps

Torque in Lbs.

Cap. Test Amps

Sensor Inspections () Torque Vents Sensor

Initial Visual Elect. Leakage Connector(s) TESTS

1

2

3

4

5

6

7

8

Deep Cycle No Final Inspection 9

10

11

12

13

14

15

16

17

1 8

1 9

2 0

2 1

2 2

Main Chg. Volts 30 Minutes Time to 1.55V Initial H2O CCs Top Chg. Volts 15 Minutes 30 Minutes 60 Minutes 90 Minutes 120 Minutes Total H2O CCs Capacity Volts 15/30 Minutes 30/60 Minutes 45/90 Minutes 51/120 Minutes Approved for service

Date

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THIS PAGE IS INTENTIONALLY BLANK

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BATTERY DISASSEMBLY

Before disassembling the battery assembly, make sure that all cell assemblies are completely discharged. This may be accomplished as follows:

1. Deep discharge the battery at the one-hour rate per steps 4 & 5, as shown on page 103.

2. After the battery assembly has been discharged as above and cooled to room ambient temperature, remove the shorting clips. Remove the socket head cap screws, the lockwashers, and the flat washer. Remove all intercell connectors. Loosen the vent and filler cap assemblies, using the vent wrench (Figure 904). The cell assemblies may now be removed by using a cell puller (Figure 906) as necessary. When removing cell assemblies from a battery, always tighten the puller to the cells and use an even straight-up pull. After removing the cell assemblies, re-tighten the vent and filler cap assemblies using the vent wrench.

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CLEANING Cleaning Procedures The battery should be kept in a clean, dry state for optimum performance. The extent of the cleaning process depends upon the condition of the battery. Several procedures are described in the following paragraphs. If heavy overcharging has occurred, gassing and spewing of electrolyte may cause a white powdery substance, potassium carbonate, to form on top of the cells. This may be removed by brushing the cells with a stiff bristle brush or a clean cloth. If necessary, the tops of the cells may be flushed with ordinary tap water. Make certain that all of the cell vent plugs are properly seated. Tip the battery at about a 45° angle with its receptacle (or power connector) facing upward. Flush with water from the top of the battery in a downward direction so as to prevent, as much as possible, any water from entering the battery can. It is permissible to use a non-conductive bristle brush to clean away stubborn dirt particles. Any excess liquid should be drained off and the battery permitted to dry. Drying may be accelerated by the use of oil-free compressed air.

WARNING: USE OF COMPRESSED AIR FOR CLEANING CAN CREATE AN ENVIRONMENT OF PROPELLED FOREIGN PARTICLES WHICH MAY ENTER THE EYES AND CAUSE SERIOUS INJURY. AIR PRESSURE FOR CLEANING SHALL NOT EXCEED 30 PSI. EFFECTIVE CHIP GUARDING INCLUDING EYE PROTECTION IS REQUIRED.

CAUTION: THE WATER USED TO WASH THE CELLS OR BATTERY WILL BECOME CAUSTIC; AVOID CONTACT WITH IT. DO NOT USE A METAL BRUSH: THIS MAY RESULT IN A SHORT CIRCUIT WHICH MAY CAUSE SKIN BURNS OR DAMAGE TO THE BATTERY. DO NOT CLEAN THE TOP CELLS WITH SOLVENTS, ACIDS OR ANY CHEMICAL SOLUTION.

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If the battery has free electrolyte on the top of the cells, drain off as much as possible, wash with water, and air dry. If the electrolyte has overflowed to an extent that it has run down between the cells, the battery should be completely discharged, disassembled, and completely cleaned before reassembling.

1. Disassembly—Disassemble the battery as described on page 301. 2. Wash the cells under running water. Do not allow the wash water to enter the cells’ interior. 3. Dry the cells with clean absorbent toweling or with an air hose. 4. Inspect each cell for cracks, holes or other defective condition. If any defects are found; replace with new cells. 5. Wash and clean all hardware to remove accumulated dirt and carbonate deposits. Heavy deposits may be removed by scrubbing with a stiff bristle brush. Corrosion preventive greases may be removed from connectors, screws, nuts, and washers by washing in alcohol or by degreasing after they are removed from the cells. 6. Allow all parts to dry thoroughly before reassembling. 7. Inspect all parts and replace those that are damaged or heavily corroded. Replace connecting straps that are burned, bent or have defective nickel plating. Polish tarnished connecting straps with a fine emery cloth being careful not to remove the plating. 8. Check the battery power receptacle for burns, cracks and bent or pitted terminals. Replace defective receptacles. They can overheat, arc, depress battery voltage and cause premature battery failure. 9. Repair or replace bent battery cases and covers, loose or damaged cover gaskets and cell holddown bars. 10. Reassemble battery. 11. Clean vent caps (vent plugs). Use hot water to thoroughly wash vent assemblies.

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CHECK / INSPECTION Inspection Prior to Installation When the battery is unpacked, a thorough inspection should be made to ensure that no damage occurred during shipment. Inspect the shipping container as well as the battery. Before putting the battery in service, check the following points carefully. 1. Damage - See if any liquid has spilled into the shipping container. This may be a sign of a damaged cell. Check for dented battery container. Check for cracked cell cases or covers. Do not place a damaged battery into service. Report any signs of improper handling to the shipping company. 2. Shorting Straps - Some batteries are shipped with shorting devices across the main power receptacle outlet terminals. Before subjecting battery to electrical service this device must be removed. 3. Electrical Connections - Poor electrical contact between mating surfaces may reduce discharge voltage, cause local overheating and damage the battery. See that all electrical contacting areas are clean. Test all terminal hardware to ensure tightness. If necessary, re-torque them to the proper value. See Table 601. 4. Liquid Level - Marathon batteries are shipped with the proper amount of electrolyte. When a battery has been discharged or allowed to stand for a long period of time, the electrolyte becomes absorbed into the plates. Since the battery has been shipped in a discharged (or partially discharged) condition, the liquid level of the cells may appear to be low. Do not add water to discharged cells. Spewing of electrolyte may take place during the subsequent charge. Charging the battery will cause the liquid level of the individual cells to rise to the proper operating level. If this does not happen, add sufficient distilled or demineralized water to the charged cells until the correct liquid level is reached.

WARNING: THE ELECTROLYTE USED IN NICKEL-CADMIUM BATTERIES IS A CAUSTIC SOLUTION OF POTASSIUM HYDROXIDE. USE RUBBER GLOVES, AN APRON AND A FACE SHIELD WHEN HANDLING THE SOLUTION. IF ANY IS SPILLED ON CLOTHING OR OTHER MATERIALS, IT SHOULD BE BATHED IMMEDIATELY WITH LARGE QUANTITIES OF WATER. IF THE ELECTROLYTE GETS ON THE SKIN BATHE THE AFFECTED PARTS WITH LARGE QUANTITIES OF WATER AND NEUTRALIZE WITH A 3% BORIC ACID SOLUTION OR VINEGAR. IF ELECTROLYTE GETS INTO THE EYES, FLUSH WITH WATER AND GET MEDICAL ATTENTION IMMEDIATELY.

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5. Cell Vents - Marathon batteries are equipped with special type vents that permit the gases to escape from the cells and prevent foreign material from entering. Do not obstruct these vents in any manner. Charging New Batteries and Cells Your Marathon battery is normally shipped in a discharged (and shorted) state. It will therefore need charging before installation (see Page 6 for charging rate and time). If by special order the battery is shipped in a charged state, it is advisable to top charge the battery at the 5-hour rate until cell voltages reach 1.55 volts per cell and check the electrolyte level. When individual cells are to be charged, refer to the caution note on Page 5 before starting charge. Installation of the Battery Ventilation Batteries evolve some hydrogen and oxygen during overcharge. It is therefore necessary to provide some means of ventilation to remove these gases from confined areas in order to prevent accidental ignition of the hydrogen. The battery cans contain vent tubes to vent the gases. The air flow should be a minimum of 5 cubic feet per hour or sufficient to keep the hydrogen concentration below 4 percent. Securing the Battery in Position When installing the battery in its permanent location, care should be taken to see that all locking devices are tight and that all electrical connections are made secure. Secure it with the proper holddowns. Poor battery connections can reduce discharge voltages and create “hot spots” that may lead to battery degradation. Make certain that the electrical contact areas are clean and that the connections are wired correctly. Checking Cell Polarities Check the polarity of each cell or group of cells to be sure that they are connected properly. The polarity of each cell is indicated by a “plus” sign molded into the cell cover adjacent to the positive cell terminal.

Charger For systems having a battery charger, check the chargers’ electrical settings to ensure proper charging of the battery.

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Quick Disconnect Devices Periodically inspect the battery quick disconnect receptacle for burns, arcing, discoloration, corrosion or powdering at rear of receptacle at terminal post risers, marbleizing of the plastic, excessive wear of plating on male pins. If any marbleizing or white powder shows, remove the connector from the battery. When using a Simpson 260, or equivalent meter, set on the lowest resistance scale. Place one probe on each pin of the Elcon/Rebling receptacle. If there is any meter deflection, or excessive wear is evident, replace the receptacle.

Inspection In the Aircraft A visual inspection of the battery in the aircraft should normally be made at least once every 50 flight hours during the first few months of service. After that, experience should indicate a proper and more meaningful schedule. The following items should be inspected and the indicated corrective measures taken if necessary.

CAUTION:

EXERCISE EXTREME CARE WHEN WORKING AROUND THE BATTERY. DO NOT USE METAL BRUSHES OR METAL BRUSH SUPPORTS. REMOVE RINGS AND OTHER METAL JEWELRY FROM THE HANDS. ANY OF THESE MAY CAUSE AN ELECTRICAL SHORT WHICH MAY RESULT IN SKIN BURNS AND DAMAGE TO THE BATTERY.

Check the battery can, cover and external battery receptacle and connections for evidence of distortion or damage. Check external connections for proper contact. Repair or replace as necessary. Check the battery for excessive heat (uncomfortable to the touch) or evidence of overheating. If present, remove battery and service in battery shop. Check the vent lines for obstructions, leaks or damage of any kind and repair or replace. Check battery box vents for obstructions or cracks and repair or replace.

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Remove the battery cover and inspect for the following: 1. Cleanliness - Under normal conditions the battery will usually remain clean except for possible dust and a light powdery deposit (potassium carbonate) on the intercell connectors and upper surfaces of the cells. These deposits may be removed by wiping with a cloth or brushing with a plastic brush. If an excessive deposit is seen, the battery should be removed and cleaned. 2. Cell Hardware - If the intercell connectors and terminals are excessively corroded, the battery should be removed from the aircraft and discharged prior to cleaning or replacing the indicated hardware. If overheated or damaged parts (cracked cell tops, etc.) are evident, the battery should be removed from the aircraft, discharged and rebuilt. If the hardware is clean, re-torque all screws or nuts as per Table 601. 3.

Vent Assemblies - Inspect vent caps, “0” rings and vent sleeves for obstructions, cracks or damaged seals. Wash and dry assemblies and remove carbonate accumulation if present. Replace if defective.

4. Excess Electrolyte - If an excessive amount of electrolyte is seen on the tops of the cells and/or a pool of electrolyte in the battery can, the battery should be removed and serviced in the battery shop. 5. Cell Electrolyte Level - Check the electrolyte level in each cell. If it is below the minimum requirement, the battery should be removed from the aircraft and water added as per Page 6. Do not add water to a battery in an aircraft because of the uncertainty concerning its state of charge. Pre-Electrical Inspection Following battery assembly and before capacity testing, the following checks are recommended: 1. Voltmeter Check Check the cells with a voltmeter following the battery circuit, making sure the cells are in proper order and the cell polarities are correct (see illustrated parts list). CHARGING A CELL IN REVERSE MAY RESULT IN PERMANENT DAMAGE. 2. Check Terminal Torque Be sure that all terminal screws or nuts are correctly torqued (see Table 601). 3. Inspect Vent Caps Check vent caps for correct seating and correct assembly. Replace damaged vents.

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4. Reconditioning After the above checking procedure has been completed, the battery should be reconditioned per Page 101.

Inspection and Mechanical Check When a battery is received in the shop for routine servicing, it should first be inspected visually for damage to the can, cover, and external battery connectors. Repair or replace these as necessary. (Discharge battery as on Page 103, before repairing can or connectors.) Check the inside of the battery for such things as cleanliness, loose or corroded connections, leaking cells and damaged hardware. Inspect the cell vent assemblies. Retighten loose vent plugs and replace damaged or missing vent plugs or vent “0” rings to prevent contamination of the electrolyte.

CAUTION:

EXERCISE CARE WHEN WORKING AROUND THE BATTERY. AVOID THE USE OF UNINSULATED TOOLS—SEVERE ARCING MAY RESULT WITH POSSIBLE HARM TO PERSONNEL AND DAMAGE TO THE TOOLS AND A CELL OR CELLS IN THE BATTERY. RINGS, METAL WATCH BANDS AND IDENTIFICATION BRACELETS SHOULD BE REMOVED. IN CONTACT WITH INTERCELL CONNECTORS OF OPPOSITE POLARITY, METAL OBJECTS MAY FUSE THEMSELVES TO THE CONNECTORS AND CAUSE SEVERE SKIN BURNS. KEEP FLAME AWAY FROM THE BATTERY.

Battery Disconnect And Receptacle Inspection The following procedure defines an inspection program to field check the battery disconnects and receptacles. BATTERY DISCONNECT BD6-3 (MS25182-2) BATTERY QUICK DISCONNECT BD13-1 BATTERY RECEPTACLE BR8-1 (MS3509)

Equipment Required Quick Disconnect Inspection Gauge (Reference Special Tools) Figure 901, Dial Calipers, capable of reading to .001 inch.

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Procedure 1. Inspection of Battery Quick Disconnect - Disengage the battery disconnect from the mating receptacle and inspect for the following: (NOTE: Do not connect or disconnect if the battery is under load.) A. Evidence of corrosion or pitting of the helix. B. Excessive free-play in the handwheel - worm assembly. C. Evidence of arcing or burn marks on the helix. This is caused when the disconnect is removed under electrical load. D. Insert the .385 inch diameter end of the inspection gauge into each helix to a depth of .437 inches. The fit shall be snug with a force to remove greater than one pound. This is to test the resiliency of the helix to an oversized pin. E. Insert the .370 inch diameter end of the inspection gauge into each helix to a depth of .437 inches. The fit shall also be snug with a nominal force to remove of one pound. This will ensure proper contact to a worn or undersized contact pin. 2. Inspection of Battery Receptacle - With the mating disconnect removed, the receptacle shall be inspected for the following: A. Evidence of corrosion or pitting on the contact pins. B. Evidence of arcing or burn marks on the contact pins. This is caused when the disconnect is removed under electrical load. C. Evidence of battery electrolyte leakage through the receptacle body and/or the contact pins. NOTE:

Electrolyte leakage can be noticed by a discoloration of the receptacle body with the glass fibers exposed.

D. Gauge each contact pin diameter using the dial calipers. The diameter shall be .375 ± .005 inches. 3. Replace defective parts.

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REPAIR Replacement of Damaged Cells If three or more cells are found to be defective, either at one time or over a period of time, it is recommended that all the cells in the entire battery be replaced because the probability is great that the remaining cells have also been damaged and will shortly have to be replaced. If a cell becomes contaminated or physically damaged and must be replaced, proceed as follows: 1.

Discharge the battery (Page 301), remove the shorting clips.

2.

Clean the battery (Page 401).

3.

Remove the end terminal connections. Save all of the hardware.

4.

Loosen all vent plugs using the vent wrench.

5.

Remove enough intercell connectors to permit the cell to be withdrawn from the battery can.

6.

Do not withdraw a cell from the battery unless a discharged or shorted replacement cell is immediately available.

7.

Withdraw the cell, using the cell puller tool shown in Figure 906. Always tighten the puller to the cell and pull in a straight-up direction.

8.

Insert the new (discharged) cell, making certain to insert the cell with the polarity symbols in the right direction. (Cells are connected plus to minus.) If the cell is difficult to insert, apply a light coat of petroleum jelly or silicone grease to the sides of the cell case before inserting.

9.

Replace the intercell connectors, assemble the hardware finger tight.

CAUTION:

DO NOT SUBSTITUTE “HOME-MADE” HARDWARE. CARE MUST BE TAKEN THAT THE POLARITY OF THE POWER RECEPTACLE IS CAREFULLY OBSERVED SO THAT, WHEN THE BATTERY IS INSTALLED IN THE AIRCRAFT, THE SYSTEM WILL FUNCTION PROPERLY.

10.

Torque the terminal connection to the values indicated in Table 601 using a calibrated torque wrench.

11.

Charge the battery per page 103.

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12.

Adjust the electrolyte level (see Page 103) and tighten all vent plugs. The battery is now ready to put into service.

Replacement of Damaged Power Connectors The battery is provided with a special quick disconnect receptacle. Should one of these become damaged, it will be necessary to replace it with a replacement part obtained from your local Marathon Aircraft Battery Distributor. Care should be taken in the removal of this connector to preserve all the hardware and gasketing, if possible, so that the new part may be installed properly. To remove the receptacle, first remove those connections which go to the end cells in the battery, thus reducing the possibility of a short circuit when the connector body is removed from the battery can. All Marathon batteries have the same hardware arrangement attaching the power receptacle to the battery as is used on the intercell connectors. When installing the replacement part, it is necessary to consult Table 601 for the torque values.

CAUTION:

DO NOT SUBSTITUTE “HOME-MADE” HARDWARE. CARE MUST BE TAKEN THAT THE POLARITY OF THE POWER RECEPTACLE IS CAREFULLY OBSERVED SO THAT, WHEN THE BATTERY IS INSTALLED IN THE AIRCRAFT, THE SYSTEM WILL FUNCTION PROPERLY.

TORQUE VALUES

CELL TERMINAL RECEPTACLE SCREWS

THREAD SIZE ¼ - 28

SOCKET HEAD CAP SCREW 3/16”

TORQUE INCH-POUNDS 100 – 125

8 – 32

20

Table 601

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ASSEMBLY (INCLUDING STORAGE) Battery Assembly Reassemble the cell assemblies into the battery can assembly. If a cell assembly must be replaced, USE ONLY NEW CELLS MANUFACTURED BY MARATHON POWER TECHNOLOGIES. Position the cell assemblies correctly with respect to polarity as shown on the Illustrated Parts List (IPL). DO NOT HAMMER TIGHT CELLS INTO THE BATTERY CAN: USE A STEADY FORCE ON THE TERMINALS TO PRESS THEM INTO PLACE. FOR EASIEST ASSEMBLY, THE CELL ASSEMBLIES AT THE MIDDLE OF A ROW SHOULD BE INSERTED LAST. Lightly polish the cell terminal surfaces with 3M Scotchbrite and wipe clean. Place intercell connectors in their correct position as shown on the IPL. Install all hardware finger-tight. Tighten each socket head cap screw to the torque specified in Table 601. CARE SHOULD BE TAKEN TO INSURE THAT THE SOCKET HEAD CAP SCREW IS NOT BINDING, DUE TO THREAD DAMAGE, OR BOTTOMING, BUT IS ACTUALLY TIGHTENING THE INTERCELL CONNECTORS. IMPROPER TORQUE MAY RESULT IN DAMAGE TO THE BATTERY. It is good practice to follow the battery assembly IPL during final tightening as this is a good double check of the correct electrical order. Do not skip around over cells; do not leave the job partially completed and come back to it. Finish the complete battery assembly once it is started. Forgetting where the tightening job was stopped is a good way to miss tightening a screw. One loose connection can permanently damage a battery and may cause an explosion.

Battery Storage The active materials of the sintered-plate in a Nickel-Cadmium battery do not react significantly with the electrolyte during use or storage. Thus, this type of battery may be stored up to five years in a discharged state without damage.

Charge Retention If full capacity is required immediately after long storage, a trickle charge of 2 milliamperes per ampere hour of capacity is recommended during the storage period. Batteries on continuous trickle charge should be checked periodically to ensure adequate electrolyte levels.

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Storage Maintenance The following procedures are recommended:

Before placing a battery in storage, the battery should be cleaned. Where operation is required immediately after removal from storage, proper cleaning is even more important to avoid the possibility of contaminants creating conductive paths within the battery case and increasing the selfdischarge rate.

If battery is to be stored in a rundown shorted-out condition (ensures equalization of cells), discharge the battery at the 1-hour rate. As each cell reaches 0.5 volts or less, place a metal shorting clip across its terminals while the load is still applied. Allow cells to remain shorted in this manner for 24 hours, then place a spring (Part #25908-001) across the receptacle positive and negative pins and remove the shorting clips from the cells. Apply grease to the intercell hardware.

Nickel-Cadmium batteries may be stored in a non-corrosive atmosphere up to five years at temperatures ranging from — 650F to +1200F; the upper limit may be extended to +1600F for shortterm storage.

Batteries stored for long periods (3 months or more) in a charged condition should be top charged at the 5-hour rate (8 amps) upon removal from storage until individual cell voltages reach 1.55 or greater. After cleaning the vent plugs and adjusting the electrolyte level, the batteries may be placed into service.

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SPECIAL TOOLS, FIXTURES AND EQUIPMENT The following tools and equipment are necessary to perform maintenance on the SP-138 battery, Part Number 30475-002.

Figure No. 901

MS25182-2

Battery Quick Disconnect Inspection

902

31379-001

Shorting Clips

903

25624-001

Vent Cap Wrench

904

32515-001

Cell Puller Nickel-Cadmium Battery Charger Marathon Christie RF-80K series is recommended

905

32415-001

Syringe

905

32479-001

Syringe Tip - Green

Part No.

Description

Calibrated Voltmeter Torque Wrench 0-150 IN-LB

On Page 902 “SPECIAL TOOLS, FIXTURES AND EQUIPMENT”, Battery Charger part number and description not included. All special tools referenced above, with the exception of the MS25182-2 inspection gauge, multimeter, and torque wrench are available in Marathon Kit 32480001.

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MarathonNorco Aerospace, Inc. COMPONENT MAINTENANCE MANUAL P/N 30475-002

Battery Quick Disconnect Inspection Gauge for MS25182-2 Figure 901

Shorting Clips Figure 902

Cell Puller Figure 904

Vent Cap Wrench Figure 903

Syringe and Tips Figure 905

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MarathonNorco Aerospace, Inc. COMPONENT MAINTENANCE MANUAL P/N 30475-002

ILLUSTRATED PARTS LIST

Introduction The purpose of this illustrated parts list (IPL) is to serve as a guide for identifying the assemblies and parts of the battery.

Exploded View of Battery The exploded view identifies all the part numbers appearing in the Illustrated Parts List by means of index numbers. This allows to locate all the removable parts of the component. It is prepared according to a functional breakdown and accompanied with parts list arranged in a logical order of disassembly.

Illustrated Parts List In this list is shown the part number, the nomenclature, and quantity of items required in each component. The appropriate index number identifies the items and their position in the component.

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100

90 81 80 70 30 50

111

11

110 112 (RBF) 114 (RBF) 113

(RBF) 11 10

(RBF) REMOVE BEFORE FLIGHT

Battery Assembly IPL Figure 1

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51

74

51

73

73

51

51 71(7) 32 72

72

31

Details IPL Figure 2

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1 10 11 30 31 32 -40 -50 51 -60 -70 71 72 73 74 80 81 90 100 110 111 112 113 114

30475-002 40132-001 15766-002 30181-02C 29078-001 16979-001

9988-174

16102-135 16102-136 16102-142 16167-006 18100-022 6560-017 10488-011 30478-002 16163-026 24583-001 23084-001 26916-004 25908-001

ASSY, BATTERY TSP-138 11-38SP100 (NI-CD) (30476-002) CAN ASSY, MARKED DUST CAP CELL ASSEMBLY, 38SP100 (30180-04C) FILLER CAP, OPTICAL VENT WRENCH LINERS SHIMS SHIM, 3.0 x 7.5 x .032 BARRIERS CONNECTORS CONNECTOR CONNECTOR CONNECTOR CONNECTOR WASHER, CRES. .265 x .563 x .032 WASHER, LOCK 1/4 SS SCREW, SOCKET HD. CAP 1/4-28 x 5/8 COVER ASSEMBLY, LINED ASSEMBLY RECEPTACLE RING, RECTANGULAR SCREW, FL.HD. SEMS 8-32 x 3/8 COVER, INSULATOR SPRING, SHORTOUT

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1 1 2 11 11 1

4

7 2 2 1 24 24 24 1 1 1 4 1 1

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