If the electrolyte level drops, add electrolyte to the upper
level line before charging.
Leaving the caps off the cells, connect the battery to a
charger, set the charging rate at 1/10 of the battery ca-
pacity, and charge it for 10 hours. For example, if the
battery is rated at 12 Ah, the charging rate would be 1.2
Keep the battery away from sparks and open flames
during charging, since the battery gives off an ex-
plosive gas mixture of hydrogen and oxygen. When
using a battery charger, connect the battery to the
charger before turning on the charger. This proce-
dure prevents sparks at the battery terminals which
could ignite any battery gases.
If the battery is not given a full initial charging, it will
discharge in a few weeks and will not recover fully
even with supplemental charging. After that it can
not be charged by supplement charging. Do not use
a high rate battery charger as is typically employed
at automotive service stations, unless the charging
rate can be reduced to the level required. Charging
the battery at a rate higher than specified may ruin
the battery. Charging at a high rate causes excess
heat which can warp the plates and cause internal
shorting. Higher-than-normal charging rates also
cause the plates to shed active material. Deposits
will accumulate, and can cause internal shorting.
If the temperature of the electrolyte rises above
45°C (115°F) during charging, reduce the charging
rate to lower the temperature, and increase charg-
ing time proportionately.
Turn the charger off, then disconnect it from the battery.
Check battery voltage. Battery voltage should be 12 ∼ 13
Check the specific gravity of each cell with a hydrometer
(see Battery Condition).
If the voltmeter or hydrometer readings are below those
specified, additional charging is necessary before the bat-
tery can be installed.
ELECTRICAL SYSTEM 15-27