Li-ion Battery Pack design

Does anyone have Li-Ion Battery construction experience?



I am constructing a D Mag-Lite with 3 x Seoul P9 LED's.

This side of things is planned, but I need to construct a 14.8V battery.

Circa 4400mAh or 6600mAh to provide sufficient runtime, probably in a water bottle package.



I appreciate the needs for Protection ciruitry (overcharge, overdischarge, short circuit, Poly switch etc.)



What is the general consensus?

Buy a battery and Charger or can one be built cheaper/better?



Your thoughts and experience would be much appreciated.



Tootall:thinking: