Plants that change batteries at the end of each shift
should have one or more centralized areas
designated for battery changing. These battery
charging areas should be equipped with overhead
hoists, conveyors, and cranes or their equivalents for
handling batteries safely and conveniently.
Battery charging areas should be adequately
ventilated, either through natural or forced
ventilation. “Adequate ventilation” is difficult to define
as it is dependent upon a variety of factors such as
number and size of batteries being charged at one
time, room size, ceiling height, airtightness of the
No Smoking, no open flame
Because an explosive mixture of gas can exist in and around charging batteries, anything that could ignite
the gas, such as open flame, arc, spark, or smoking materials should be prohibited in battery charging
areas. It is recommended that “No Smoking” signs be posted prominently in charging areas.
Insulated Battery Charging Racks
When batteries are charged in racks, the racks should be insulated to prevent the possibility of sparking.
The supports on which a battery rests should be made of nonconductive materials or be suitably insulated.
Before connecting a battery to, or disconnecting it from a charger, the charger should be turned OFF. Live
leads can cause sparking and arcing as well as undesirable pitting of the contact surfaces of plugs or
In addition to automatic sprinkler equipment that might be present, charging areas should be equipped with
a suitable hand-operated fire extinguisher. Consult local fire authorities or your insurance carrier for the
class and size needed and for recommended mounting locations.
The ventilation system in a charging room should conform to local codes and ordinances. If the average
hydrogen concentration throughout the charging room does not exceed 1% by volume, the ventilation is
considered to be satisfactory. (Concentrations between 4% and 74% are explosive.) A variety of instruments
such as combustible gas indicators and flammable vapor indicators are commercially available for
continuous and automatic analysis of hydrogen concentrations in the air. Contact HAWKER® if more
information on these indicators is desired.
When charging an enclosed or covered battery, whether it remains in the truck or is placed on the rack,
always keep the battery tray cover and the truck compartment cover OPEN throughout the entire charging
period. Opening the covers helps to cool the battery and disperse the gases.
Vent caps stay in
Keep the vent caps closed and in the cells at all times,
except when removal is necessary to service or repair
the cells. This precaution reduces the probability of
electrolyte splash and prevents foreign matter from
entering and damaging the cells.