Here is an early preview of a 12V Custom LiFePo4 pack we are working on.  Missing from this image is the outer case and terminals.  The outer case will be made from lexan and is extremely durable.  It can be made water proof for marine environments.  The pack is assembled by hand and can be customized to fit the intended use. This pack is able to provide peaks of up to 400 amps of current and has a capacity of at least 20Amp hours. It's powerful enough to be used as a start battery for an automobile or as the drive battery for a trolling on a boat, or even to drive a golf cart.  This pack is based on a highly tested design and is built from the best materials available.  With an expected lifetime of over 7000 cycles, this battery will provide power for many, many years to come. To get more information on the possibility of using one of these packs on your next project, feel free to email me at mcstar@gmail.com.