Originally Posted by jharker
Did you mean "additional battery" or "bigger battery"? The power board of the v1 looks like the one in Figures 4 and 5 of this guide
. If your board looks the same, then it's probably the same board.
I haven't yet written part 3 of my iLiad Battery Hacks article, but...
Basically, the v1 power board contains an EEPROM chip that can be reflashed (kind of like new firmware) to support a new battery size. This is probably what iRex did during battery upgrades. So if you got the v1 batteries upgraded, or you own a v2, the board is probably the same as the original v1 board (and should be interchangeable).
I have a v2, but the board looks the same as in your thread so they must not have changed the actual board from the v1 to the v2. I'll give them a call on Monday and see if I can beg them to sell me a power board. If not, I'll probably try to pick up the used flybook on ebay and cannibalize it for parts.