2011 Toyota Prius Owners Manual - Page 472

4-3. Do-it-yourself maintenance n 12 volt battery exterior Make sure that the 12 volt battery terminals are not corroded and that there are no loose connections, cracks, or loose clamps. Terminals Hold-down clamp n Before recharging When recharging, the 12 volt battery produces hydrogen gas which is flammable and explosive. Therefore, before recharging: l If recharging with the 12 volt battery installed on the vehicle, be sure to disconnect the ground cable. l Make sure the power switch on the charger is off when connecting and disconnecting the charger cables to the 12 volt battery. 4 Maintenance and care 449 PRIUS_U (OM47685U) DVD