LiFePO4 vs LiPO？which one should I choose?

[zhangjuan]

Hey,My group and I are designing an electric bike and we're looking into batteries for the bike.So far I've been looking into Lithium Polymer batteries for their power-weight ratio and fast charge cycles. But everywhere I look, people else seems to be using Lithium Iron Phosphate batteries.Aside from safety and longer life cycle, I can't seem to find an advantage that LiFePO4 has over LiPO (it's even heavier for the same capacity).Can someone direct me to a website that shows the comparison between these two batteries. Or can you give me a reason why companies prefer lifepo4 batteries over LiPO for their bikes.Thanks!:wink:

 

[A123rc]

I worked with the Li Poly developers when they first came out (late 90's) and they had problems if they were allowed to discharge too far: could develop an internal short and catch fire. They were too unreliable to use in consuler products. Not sure about the current generation.
My tip is you should choose the safe one, go and collect more information about it!:grin:

 

[Mehrshad74]

Except for more Kwh/kg(about 20%) of LIPOs there is no advantage in using them for EV or EB.
lifepo4 has flatter discharge curve and 10times life time is not a minor advantage.
Lifepo4 is not as sensitive as lipos in overdischarge condition as you mentioned.