The Hope 4 Cell ES Battery the large quad cell 2600mAh rechargable Li-Lon battery that includes a Energy Status (ES) with an integrated power level display.
4 Cell ES Battery is compatible with the R8, R4+ and R2 lights.
Customer Reviews of Hope 4 Cell ES Battery
If you own a Hope light this is what you need giving plenty of power plus a power indicator and although heavy if used with extension cable you can fit it into a jacket pocket instead of attaching to bike which I found a much safer option and easier for removal of lights.
If you do need a battery for your Hope lighting system, then you can buy this one.I had the earlier 4 cell version, this one is more metal and solid but a bit heavier.It does however, and this is why I really wanted it, have a battery level indicator thingy, so it takes some of the guesswork out of energy levels.FaceWest were the only people in the UK that I could find who sold this on it's own so I was very pleased to be getting it.