Toyota PRIUS Manual page 502

4-3. Do-it-yourself maintenance
 Caution symbol
The meanings of each caution symbol on the top of the battery
are as follows:
No smoking, no naked
flames, no sparks
Shield eyes
Keep away from children
Before recharging

When recharging, the 12-volt battery produces hydrogen gas which is flam-
mable and explosive. Therefore, observe the following precautions before
recharging:
If recharging with the 12-volt battery installed on the vehicle, be sure to

disconnect the ground cable.
 Make sure the power switch on the charger is off when connecting and
disconnecting the charger cables to the 12-volt battery.
502
PRIUS PHV_OM_OM47831E_(EE)
Battery acid
Note operating
instructions
Explosive gas