C&D Technologies LIBERTY 1000 Series, Installation And Operating Instructions Manual

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CAUTION
RECHARGE BATTERIES AS SOON AS POSSIBLE AFTER AN
EMERGENCY DISCHARGE. Failure to recharge batteries
immediately after emergency discharge may lead to sulfation
or, in the case of deep discharge, to complete battery failure
due to hydration. If recharging at equalize voltage is
impractical, recharge at float voltage.
1.3 Low float voltage and sulfation
Either because of incorrect charger voltage adjustment or excessive
intermittent or static loads paralleling the charging source or low
operating temperature, a battery may not receive adequate charge. In
some cases, the charger may even be turned off, erroneously or by
choice. The net result is a battery left in a partially discharged
condition. The first observable signs may be erratic cell voltages.
Although not visible to the observer, the plates will become sulfated.
If you suspect sulfated plates, contact C&D Technologies Technical
Services Department for assistance. Sulfated batteries are partially
charged batteries and have not completed the electrochemical reac-
tion of recharge. Accordingly, they will have reduced capability and
available capacity. If allowed to remain in a partially charged condition
for an extended period of time, sulfated batteries may suffer
irreversible damage, requiring replacement.
1.4 Hydration
A battery that has been severely over-discharged and left in a
discharged condition without immediate recharge is subject to damage
known as hydration. This is a phenomenon in which the electrolyte
specific gravity has been reduced to a value so low it permits the lead
components to dissolve into the electrolyte.
The reaction of dissolution forms many compounds and salts,
generically referred to as hydrate. On recharge these compounds
react to clog separator pores and form metallic lead. As time passes
thousands of short circuit paths are created in the separators placed
between the positive and negative plates to provide electrical
insulation. Very often, the effect of these short circuits goes unnoticed
except for a slight increase in charging current. As the reaction
continues, however, short circuits become so extensive it is almost
impossible to keep the cells charged. Finally, the cells experience total
failure.
1.5 Open circuit - late installations
As soon as a battery is disconnected from a charger, local action
(discharge) begins. This is caused by inherent internal losses within
the cell. In the case of Liberty Series 1000 cells, a self-discharge is
expected to occur at a rate of “up to 3.0 percent” of full charge per
month at 77°F (25°C). Therefore, if cells remain, for whatever reason,
on open circuit (with no charge supplied) for prolonged periods of time,