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Old 02-12-2012, 01:02 PM   #50
_cy_ OP
Beastly Adventurer
 
Joined: Sep 2011
Location: Tulsa, Oklahoma
Oddometer: 5,626
it's becoming obvious this 20AH test battery is more than capable of starting a motorcycle during warm to moderate cold temps above 40f degrees. what a LOT of folks including me wants to know is how will lithium iron phosphate batteries perform under old temps under 40f degrees to about 15f degrees. there are exceptions of course, but not many folks will ride much if any below that.

more observations on how a 20AH lithium iron phosphate battery performs at colder temps

resting voltage 13.4v @ 38f degree .. choke off, not ready for bike to start yet.
first few cranks draws about 105amps... turns over med speed. motor wants to start even with no choke. voltage under load is about 9.5v.. jumping all over, hard to read meter.

meter used Fluke 87V received new from Fluke. Calibration verified by Fluke and Martel MC1000 calibration tool.

after 4 crank cycles with engine spinning over plenty fast enough to start. battery was given a rest. voltage recovered to 13.29v @39f degree in garage.

next 2 crank cycles .. 13.29v @39f draw 155amp... engine turned over very fast. would have easily started. seems a cold battery does much better after being short cycled a few (2-3) times to warm up. then allowed rest to recover.



resting a few minutes, voltage recovering


after 4 crank cycles with engine spinning over plenty fast enough to start. battery was given a rest. voltage recovered to 13.29v @39f degree in garage.


_cy_ screwed with this post 02-12-2012 at 01:11 PM
_cy_ is online now   Reply With Quote