Why voltage is 8.4V when full charged, will it work?
9V NiMH Battery Voltage range: 7.2V - 8.4V;
9V Li-ion Battery Voltage range: 6V - 8.4V;
9V Alkaline battery voltage range: 6V - 9.6V;
9V rechargeable battery can work perfectly with any standard 9v battery devices. If few need battery voltage more then 8.4V, we suggest you buy Alkaline 9V battery.
Package: 1 x 4 slot 9V charger 1 x usb cable 4 x 9V batteries 1 x user manual