Originally Posted by Mike the Yank
They sound like Lipo's, hate to say but you will need all that circuit board stuff to make sure they don't over charge, over charge them and they can exploded and burst into flames.
computer batteries are not lead acid batteries or similar they need a very specific charging rate...
I used to be a very skilled electric hobby car enthusiast...and batteries and how to charge and DISCHARGE them is a science that you can learn a lot from
and all the new lithium style batteries need very specific charging and especially the need to not be overcharged they are also designed to be drained to almost zero volts...and charged back up fully...
nicads and nimhs are better at this but they simply are not designed to be topped off all the time..its really easy to make a battery pack the problem is on a bike they will simply burn up(how long do tusk brand battery packs last? like 6 months?) even the big dualsport kits come with crap batteries.
you need to think about getting a small deep cycle marine style or rv type unit...
just my thoughts and cents
good luck on the bike, coming along great