Battery Pal

[bigpilot]

Has anyone seen this? I think it's pretty nifty. But it's also quite expensive.

Can anyone recommend something similar but cheaper?

 

[MarkT]

Four NiMH's in series make a 5V supply that's rechargable in-place with care - NiMH are about 1.3V each charged, dropping to 1.15V or so when drained, giving 5.2V down to 4.6V. NiMH has no fire risk either.