Charging Lead-Acid Batteries - Teledyne 913 Installation And Operation Manual

Power Products Guide
Section 2 Batteries
2.3.1 Charging Lead-Acid
Batteries
2-10
swell and crack the case. This will ruin the battery and
could also release toxic substances.
• You can easily damage a gelled-electrolyte
lead-acid battery by overcharging. By necessity, the
amount of water in a gelled-electrolyte battery is quite
limited. The batteries have a one-way safety vent in
each cell that releases water when overcharging causes
the pressure to build up inside the battery. Unlike
wet-cell lead-acid batteries (such as automotive types),
you cannot replace the water. Repeated venting will dry
out the cells and kill the battery. Optimal charging
causes the battery to release no water vapor and very
little gas from the plates.
• Lead-acid batteries are not charged the same way
as a nickel-cadmium battery. Proper charging is done
with a constant voltage and a tapering (or declining)
current.
Chargers for nickel-cadmium batteries typically use a con-
stant-current method. Overcharging is more likely to damage a
lead-acid battery by forcing the vents open and drying it out.
Isco's Model 963 Single Station Battery Charger can be used
to charge lead-acid batteries.
In addition, the Isco Model 965 Five-Station Battery
Charger has outputs that can be switched for lead-acid bat-
teries.
Some battery manufacturers recommend charging the lead-acid
battery near room temperature (70° F or 23° C), if possible.
Chargers are typically designed to operate at room temperature.
Temperatures deviating significantly either direction from room
temperature may cause inaccuracies in charging the lead-acid
battery, with potentially harmful long-term effects. The Model
965 Five-Station Battery Charger contains compensation for
charging at higher and lower temperatures, but the other
chargers do not.
When charging lead-acid batteries of any type, please consider
the following:
• Disconnect the battery from the equipment it is
powering before charging.
• Connect the battery to the charger before plugging the
charger in or turning it on; this prevents sparks.
• Never charge the battery in a sealed container, nor in an
unventilated room.
• Do not let the charger run unsupervised or for a long
period of time.
• Do not charge the battery upside down.
• Charging produces explosive gases; do not charge near open
flames or sparks.
• Do not smoke around the battery while it is charging.