Lithium Ion Polymer batteries and cold weather
Does anyone know if cold temps might effect the power output of this type of battery? I do know that it is best to store these batts at about 40% charge and the colder the better to perserve shelf life, but how does outside weather effect the power output of these batts?
Does cold like 40 degrees F not allow the full power potential or like is there any real gain or loss due to high/ low temperatures?
Thanks for any info
It works like this...
Colder = less power and larger voltage drops. (*see below)
Colder = longer shelf life and longer cycles IF used to only about 50% capacity.
(Ultimately meaning less power and more cycles)
Warmer = more power and less voltage drops.
Warmer = shorter shelf life and shorter cycles.
(Ultimately meaning more power and less cycles)
End all is, batteries like warm better than cold. (but not by much.)
Now for motors, it's different...
Motors become more efficient when their temperature is lower and less efficient when their temperature rises.
Ultimately, the average power/cycles in the entire "system" is balanced between colder and warmer temperatures.
Lithium Polymer batteries really hate very cold and very hot.
Lithium Iron Phosphate batteries tolerate cold and hot better.
Lead Acid batteries REALLY hate cold.. As a matter of fact, at about -10F (for an extended period of time), lead acid batteries can actually FREEZE. (that's why it's difficult to start your car in sub freezing temperatures. *see above)
Last edited by Sangesf; 12-26-11 at 01:13 PM.
Thank you for the info, at least im sure nothing is wrong. When i first got the bike it was close to around the high 50's F now its down to the mid 30's F. Since the Lithium Polymer batteries are really expensive and really hate very cold and i do to , i think ill pack it up for the winter.
OR they have these "battery warmers" that keep batteries warm while riding..
That should help.
Also, after being in use for about an amp/hour, the batteries SHOULD warm up themselves.. But keeping them in the battery warmers will definitely help.
Automotive battery warmers and/or chemical hand warmers can be used..
Do a google search and see what you can find.
Last edited by Sangesf; 12-26-11 at 02:13 PM.
I didnt think about the warmers. I've also been thinking that if it was 34 degree F out that at 30mph the chill factor would have to be abit below freezing and the batts are just in a frame bag.
Thanks again for the info
If the battery is kept & charged up indoors @ room temp. she's warm & toasty @ the start . I've done 185 miles the last month since I built my E-bike & although a mild winter thus far here on long island NY it's still averaging low 40's or so & my battery seems to perform to spec.
I would imagine bitter cold days is a different ballgame