here is something i found on the new lifepo4 batteries
Benefits of LiFePO4 batteries
Flexible Form Factor - Small in size and light in weight 1/3 weight of Lead Acid and 65% weight of NIMH.
High Rate Capability - For all high power output application
Extraordinary Long Cycle Life - over 1000 times recharge, actually lowers the cost of ownership, you could use them for more than 5 years, would be over 8 times life of Lead Acid and 3 times of NIMH, 2 times most Lithium batteries
Extremely Safe Chemistry - made of stable materials, High intrinsic safety , no explosion & will not catch fire under collision, over charged or short circuit. High thermal stability of phases up to 500C.
Wide Working Temperature Range - From -4 F to 150 F (-20C to +70C) Extremely cold and extremely hot weather will not effect its performance
No Memory Effect
What's LiFePO4
LiFePO4, lithium iron phosphate as cathode, a kind of advancing technology to change the world!
The safety characteristics inherent to LiFePo4 technology result from the incorporation of phosphates as the cathode material. Phosphates are extremely stable in overcharge or short circuit conditions and have the ability to withstand high temperatures without decomposing. When abuse does occur, phosphates are not prone to thermal runaway and will not burn. As a result, LiFePo4 technology possesses safety characteristics that are fundamentally superior to those of Lithium-ion batteries made with other cathode materials.
LiFePo4 technology does not contain any heavy metals and does not exhibit the "memory effect" of Nickel-Cadmium and Nickel-metal Hydride solutions. LiFePo4 technology demonstrates excellent shelf life, long cycle life and is maintenance free.
Another key benefit of our LiFePo4 technology is its flexibility, both in terms of battery application and cell design. It can be used in wound cylindrical, wound prismatic and polymer battery construction types and manufactured to fit smaller applications.
The advantages of traditional Lithium-ion coupled with the safety features of phosphates, make LiFePo4 technology the Lithium-ion technology for the future. LiFePo4 Lithium-ion technology utilizes natural, phosphate-based material and offers the greatest combination of performance, safety, cost, reliability and environmental characteristics.