CYL GP- 5212732 - Caterpillar

Keep all sparks and flames away from the batteries. A spark can cause an explosion from the flammable vapor mixture of hydrogen and oxygen that is released from the electrolyte through the battery outlets. Injury to personnel can be the result.
The battery circuit is an electrical load on the charging unit. The load is variable because of the condition of the charge in the battery. Damage to the charging unit will result, if the connections, (either positive or negative) between the battery and charging unit are broken while the charging unit is charging. This is because the battery load is lost and there is an increase in charging voltage.High voltage will damage, not only the charging unit but also the regulator and other electrical components.
9S1990 BATTERY CHARGER TESTER
Never disconnect any charging unit circuit or battery circuit cable from battery when the charging unit is charging.
Load test a battery that does not hold a charge when in use. To do this, put a resistance across the main connections (terminals) of the battery. For a 6, 8 or 12V battery, use a test load of three times the ampere/hour rating (the maximum test load on any battery is 500 amperes). Let the test load remove the charge (discharge) of the battery for 15 seconds and, with the test load still applied, test the battery voltage. A 6V battery in good condition will show 4.5V; an 8V battery will show 6V; a 12V battery will show 9V. Each cell of a battery in good condition must show 1.6V on either a 6, 8 or 12V battery.Special Instruction Form No. SEHS6891 is with the 9S1990 or 1P7400 Charger Tester and gives the battery testing procedure.Charging System
5P300 Electrical Tester. Make reference to Special Instruction Form No. SEHS7006 and to the instructions inside of the cover of the tester, when testing with the 5P300 Electrical Tester.The condition of charge in the battery at each regular inspection will show if the charging system is operating correctly. An adjustment is necessary when the battery is always in a low condition of charge or a large amount of water is needed (one ounce per cell per week or every 50 service hours).Test the charging units and voltage regulators on the engine, when possible, using wiring and components that are a permanent part of the system. Off the engine (bench) testing will give an operational test of the charging unit and voltage regulator. This testing will give an indication of needed repair. Final testing will give proof that the units are repaired to their original operating condition.Before starting on the engine testing, the charging system and battery must be checked. See the following Steps.1. Battery must be at least 75% (1.240 Sp. Gr.) fully charged and held tightly in place. The battery holder must not put too much stress on the battery.2. Cables between the battery, starter and engine ground must be the correct size. Wires and cables must be free of corrosion and have cable support clamps