Open-Circuit Voltage Test - Crown C48-2+2 Owner's Manual And Service Manual

OPERATION AND SERVICE INFORMATION
If any specific gravity readings still register low then follow the steps below.
1. Check voltage level(s).
2. Perform charging. Refer to the charging section for the proper procedure.
3. Take specific gravity readings again.
If any specific gravity reading still registers lower than the specification of 1.280±0.01g/cm3 then one or
more of the following conditions may exist:
1. The battery is old and approaching the end of its life.
2. The battery was left in a state of discharge too long.
3. Electrolyte was lost due to spillage or overflow.
4. A weak or bad cell is developing.
5. Battery was watered excessively previous to testing.
Batteries in conditions 1 - 5 should be taken to a specialist for further evaluationor retired from service.
NOTE
◆ Do not smoke near batteries.
◆ Do not overtighten terminals. Doing so can result in post breakage, post meltdown, or fire.
NOTE
electrolyte specific gravity is 1.10g/cm3 under full charging, if can not test or not air bubble in
cell during of charging, then short circuit happened.

Open-Circuit Voltage Test

For accurate voltage readings, batteries must remain idle (no charging, no discharging) for at least 6 hrs,
preferably 24 hrs.
1. Disconnect all loads from the batteries.
2. Measure the voltage using a DC voltmeter.
3. Check the state of charge with Table 1.
4. Charge the battery if it registers 0% to 70% charged.
If battery registers below the Table 1 values, the following conditions may exist:
1. The battery was left in a state of discharge too long.
2. The battery has a bad cell.
Batteries in these conditions should be taken to a specialist for further evaluation or retired from service.
TABLE 1. State of charge as related to specific gravity and open circuit voltage
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Owner's Manual and Service Guide