Hi GKM, I run my EI off a regulator. Tried both 5v and 6v (jumper selected and volt meter checked) and decided that I didn't really see a difference in performance. Did a few test runs with a 4 cell NiCd pack too.

If you read the instruction manual, I think the required power supply range is stated as being from 4.8v to 18v, so I guess anythig from a 4 cell NiCd through to an unregulated 4S LiPo pack would, at least in theory, be workable.

Short answer - if you're running ok with the 4.8v, I wouldn't bother changing anything.