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Old 04-30-2013, 02:44 PM   #468
_cy_ OP
Beastly Adventurer
Joined: Sep 2011
Location: Tulsa, Oklahoma
Oddometer: 6,386
Originally Posted by achtung3 View Post
It is an MV F4 05
The bike itself runs hot, 160-190+.
The normal temp around here is between 50-60, now somedays maybe in the upper 60's.
OK got most of info needed, MV is a 1,000cc class modern bike being operated in mostly warm temps ... what size Speedcell?

not familiar with Speedcell. with the rapidly adoption of LiFePO4 batteries by the motorcycle industry. unlike conventional lead acid mfg who's got LOADS of osha, epa, etc. etc. etc. to deal with.

literally anyone can start a LiFePO4 battery business in their garage with little to no regulation.

Speedcell appears to use A123 cells (26650) in 4s, then stacked in parallel to add more AH. 4cell = 2.3AH 8cell = 4.6AH and so on...

recommendation is to add a hard protective layer around battery. LiFePO4 batteries with only a shrink wrap protecting metal straps that connect cells are especially vulnerable to dead shorts.

if said LiFePO4 battery gets discharged HARD ... straps will get hot .. possibly melting shrink wrap. once shrink wrap is melted, metal straps are exposed. which could result in a fire from a dead short.

shrink wrap is designed to be heated with an airgun. which then shrinks wrap around cells. heat from straps connecting cells will shrink wrap further. with a good chance of exposing strap, which could result in a dead short. IHMO shrink wrap alone is not a good choice for an outside layer on LiFePO4 motorcycle batteries. your mileage of course may veri...

it's not unusual for a motorcycle to draw 200+ amps... 4.6AH battery discharge at 43C or 200amps. those tiny straps carry a LOT of current and can heat up.

A123 (26650) cells are rated:
  • Maximum Continuous Discharging :70A, 28.0C rate
  • Maximum Impulse Discharging (< 10 sec): 120A, 48.0C rate

_cy_ screwed with this post 04-30-2013 at 04:19 PM
_cy_ is offline   Reply With Quote