These Li-Po batteries utilise the same battery technology as phones and laptop batteries to give superb performance in a standard AAA battery size. 

Another advantage of these batteries is they don't require any special battery charger, they can be charged using the included USB-C cable and a phone charger (not supplied) that plugs into the side of the battery and they are fully charged in 1.5 hours. 

They are ideal for use in electronic equipment that requires high capacity such as digital cameras, torches, MP3 players, wireless mice, hand held video games, toys and remote controls. Unlike traditional batteries these never loose voltage and will output 1.5V consistently until their charge is depleted.