Trojan Battery User Guide
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USER’S GUIDE
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8.3 Specific Gravity (flooded/wet batteries only)
î Fill and drain the hydrometer 2 - 3 times before drawing a sample from the battery.
î Measure specic gravity readings for all battery cells.
î Correct specic gravity readings for temperature by adding 0.004 for every 10°F (5°C) above
80°F (27°C), and subtract 0.004 for every 10°F (5°C) below 80°F (27°C).
î If every cell in the battery set is below 1.235, the batteries may be undercharged and require
recharging.
î If any battery has a specic gravity variation of more than 0.030 between cells, equalize the set.
î If there is still a variation there may be a failed battery.
8.4 Open Circuit Voltage Testing
This is the least preferred method of evaluating the condition of a deep-cycle ooded/wet battery, but is
the only method for AGM and gel batteries.
î For accurate voltage readings, batteries must remain idle at least 6 hours, preferably up to 24 hours.
î Measure the individual battery voltages.
î If any battery voltage is greater than 0.3V compared to other batteries in set, equalize the set (deep-
cycle ooded/wet batteries ONLY). Refer to Equalizing Section 4.4.3.
î Measure the individual battery voltages again.
î If any battery voltage is still greater than 0.3V compared to any other battery in the set, you may have
a failed battery.