The CH-70DCH is a 12 volt DC charger with charge times of 1 hour for the BP-70R and BP-70I, 90 minutes for the BP-70E and BP-70EI and 3 hours for the BP-70MH. It can be plugged directly into an automotive cigarette lighter and has a built in overload fuse protector. Although the charger is composed of a lightweight printed circuit, the battery drain on an automotive system is considerable and the engine should be running while the battery is being charged. We do not recommend battery charging while the engine is off. The battery should be secure while the vehicle is in motion to avoid it from bouncing out of the charger.