since this topic is going to come up anyways...
might as well get started
very few shreds of hard data are available.
For the number of LiFePO4 batteries out in the field. very few instances of LiFePO4 fires.
LiFePO4 batteries must be wired carefully to your bike's wiring harness, as they can source high enough currents to start some amazing fires in shorted wiring. Be dead certain positive connection(s) will not ground out.
seldom are LiFePO4 batteries identical size/shape to factory battery. take extra care to strap non-OEM sized battery securely to prevent any possibility of damage to outer case. if an internal connector strap grounds out. a fire could result.
note pictures below showing LiFePO4 fire are from wiring shorting out. Note LiFePO4 cells were still putting out full volts afterwards.
wiring shorting out, not battery failure seems to be the common thread so far for LiFePO4 fires.
it's worth noting that identical shorting problems could happen with wet lead acid, AGM or Gel cell batteries. dead shorts can easily result in a nasty wiring harness fire.
more to come...
here's an example of a LiFePO4 fire thought to be caused by shorted internal wiring. a valid example yes, but without laboratory analysis still not considered hard data.
The Lifepo4 FIRE!!!! (the top secret photos)
Last year we had a problem with one of the boxes that Headway sent us.
The batteries were NEVER the problem nor the so-so BMS. It was the poor wiring job provided by hungover employees, at least it looked that way.
I cannot say this enough times, FUSE your battery packs!!!!! (note this in context of Electric bike which draws aprox 33 amp continuous load)
Just to show you the robustness of the headway battery, here is one that was burnt to crackly crisp and still have full voltage!!!!
this is worth considering if one is looking into LiFePO4 batteries