AP4001 4V battery

The AP4001 is a 4 volt battery manufactured by Ryobi. It is part of the TEK4 battery system.

When fully charged the battery has a voltage of 4 volts but during use its nominal voltage is 3.6 for this reason the battery is classified here as 3.6 volt.

The battery contains a single 18650 Lithium Ion cell inside a plastic housing with metal contacts on the top.

Ryobi does not specify the capacity of this battery but the marking on the battery states 5 watt hour, which at 3.6 volt is 1.3 Ampere hour.