Buick 1993 Skylark Owner's Manual page 117

If the "Check Oil" light comes back on, the engine oil
should be brought up to the proper level, see "Engine
Oil" in the Index.
"Battery" Light
When you turn the key to RUN, this light will come on
briefly, to show that your alternator and battery charging
systems are working. If the light stays on, you need
service, and should take your Buick to the dealer at
once. To save your battery until you get there, turn off
all accessories, and set your air system to OFF.
Volts Gage (Option)
This gage shows the voltage in the electrical system.
The normal range is 11 to 15 volts. If the reading stays
outside the normal range, have your Buick dealer check
the electrical system.