Battery Packs and Wiring

SilverSurfer Posts: 1,931
edited December 2008 in Workshop
I've got an EL-300, 2 Tesco Crees and a couple of Cateye rears - I'd like a central battery repository so that I can stuff a battery pack into a seat pack.

Ideally with a detachable block so I can uncouple the seatpack and take it indoors with me (leaving the wiring loom on the bike).

I presume that I'll have to do some calcs for voltage etc. and a bit of DIY? Is there a techie out there that can tell me what I need to do in layman's terms?