Recharging Sealed Lead Acid Batteries

The sealed lead acid (LA) batteries supplied by PANAVISION for the purpose of powering cameras and camera accessories are far removed from the lead acid type batteries used for automobiles. Unlike the common lead acid battery the sulphuric acid electrolyte of LA batteries is solid and cannot be spilled. From the outside they look very similar to cylindrical type Nicad batteries but that is where the similarity ends.

The nominal voltage of LA cells is 2 volts. Twelve LA cells are required to make up a 24v battery compared to twenty Nicad cells.

LA batteries must be charged at approximately 2.5v per cell using a constant voltage charger. For this reason constant current chargers designed to be used with Nicad batteries are not suitable for use with LA batteries, and vice versa. Only chargers supplied by PANAVISION for use with particular types of batteries should be used with those batteries. Many batteries supplied by PANAVISION incorporate chargers within the battery case so there can be no confusion.

Charge Retention and Performance

Like Nicad batteries, LA batteries store their charge best when kept in a cool atmosphere but unlike Nicads should only be stored in a fully charged state. They will, however, store their charge better than Nicads in warm conditions and will continue to perform at temperatures slightly lower than Nicads.

Unlike Nicad batteries, LA batteries do not suffer from the memory effect. Furthermore, under-discharging between recharging will increase the number of charge-discharge cycles to be expected from the life of a particular battery.

1. Connected blocks of LA cells, 2. LA battery with built-in charger, 3. The voltage/amperage meter of an LA battery, 4. Block battery with built-in charger.

SEALED LEAD ACID BATTERY TEMPERATURE v CAPACITY TABLE