TM-9-2350-311-20-1

TM 9-2350-311-20-1

SECTION Ill. BATTERY TESTING

I-6 GENERAL

The STE/ICE-R battery test procedures allow the user to evaluate the condition and state of charge of vehicle/equipment

batteries. These procedures use the battery internal resistance and battery resistance change measurements. Battery

internal resistance evaluates the state of charge of the. battery. Battery resistance change evaluates the battery

condition.

The battery state of charge is a measure of the amount of energy stored in the battery. A fully charged battery contains

the maximum amount of energy stored. If the battery fails the battery state of charge evaluation, the battery may be

recharged to return the battery to full charge.

The battery condition is a measure of the battery’s ability to accept and maintain a good charge. A battery in poor

condition may be able to be fully recharged. However, a battery in poor condition with a full charge will lose its charge

more quickly than a battery in good condition with a full charge. If a battery fails the battery condition evaluation, the

battery should be replaced.

The procedures for testing the M109 batteries are listed on three battery test cards. Each card describes procedures for

evaluating the different combinations of batteries:

Complete battery pack

Series pair of batteries

Individual batteries

I-7 BATTERY PACKS

A battery pack is the combination of four or more batteries in a particular circuit of a vehicle/equipment, i.e., the starting

circuit. Testing the batteries in a pack evaluates the general condition of the pack as a whole. Note: the results of a

battery pack test may be misleading. A single battery from a pack of four may be bad, even though the pack as a whole

may pass the tests. This can happen if the other three batteries in the pack are in very good condition.

I-8 SERIES PAIRS

A series pair is one in which the negative terminal of one battery is connected by a cable to the positive terminal of

another battery. This test configuration should be used when the battery pack test has failed and the user wants to

further identify any bad battery pair.

NOTE

Testing both series pairs yields a better evaluation than testing the pack as a whole.

I-63

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