Buick LaCrosse Owner's Manual page 364

The eAssist system high voltage
battery is cooled with air drawn from
the vehicle interior. The cold air
intake for the battery is located
behind the rear seat, on the filler
panel. Do not cover the intake.
Battery posts, terminals, and
related accessories contain lead
and lead compounds, chemicals
known to the State of California to
cause cancer and reproductive
harm. Wash hands after handling.
Batteries have acid that can burn
you and gas that can explode.
You can be badly hurt if you are
not careful. See
or
for tips on working around a
battery without getting hurt.
Infrequent Usage: Remove the
12 volt battery black, negative ( )
cable from the battery to keep the
battery from running down.
Extended Storage: Remove the
12 volt battery black, negative ( )
cable from the battery or use a
battery trickle charger.
Remember to reconnect the battery
when ready to drive the vehicle.