Volvo Penta D4 Operator's Manual page 72

Maintenance: Electrical system
70
Battery. Charging
WARNING! Danger of explosion! The batteries
give off hydrogen gas during charging which
when mixed with air can form an explosive gas –
oxyhydrogen A short-circuit, naked flame or
spark can cause a large explosion. Ensure that
the ventilation is good.
WARNING! The battery electrolyte contains ex-
tremely corrosive sulfuric acid. Protect your skin
and clothes when charging or handling batteries.
Always use protective goggles and gloves. If
battery electrolyte comes into contact with un-
protected skin wash off immediately using plenty
of water and soap. If battery acid comes into
contact with the eyes, flush immediately with
plenty of water and obtain medical assistance
without delay.
If the battery has discharged it must be charged. If
the boat has not been used for some time charge the
battery and then trickle charge it (see manufacturer's
recommendations). A poorly charged battery will be
damaged and may burst in cold weather.
IMPORTANT! Follow the instructions supplied
with the battery charger carefully. To avoid elec-
trolytic corrosion when an external charger is
connected, always disconnect the battery leads
before connecting the charger.
When charging, unscrew filler plugs but leave them in
their holes. Ventilation should be good, particularly if
the batteries are being charged in an enclosed area.
WARNING! Always switch off the charging cir-
cuit before removing the battery charger con-
nectors. Never mix up battery positive and nega-
tive terminals. This may cause sparks and an
explosion.
Special instructions apply when boost charging the
batteries. Avoid boost charging the batteries as it will
shorten their service life.