What level of charge to leave a Bosch battery at??

Barrio Barranco

Esteemed Pedelecer
Nov 24, 2018
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So, Bosch recommend that you leave a battery with ideally 3 bars/60% charge if you are not going to be using it as depleted and fully charged are bad for the battery. That's fine if you put it in winter storage and check it, but in my situation I might go out just at the weekend through the winter (I did 16km off road tonight and it was a bit ropey...) but then this weekend is due for -5c so I'm not likely to go out due to ice/battery life/ wind chill so depending on what the weather does should I just charge the battery after use to 3 bars, and if I decide to go out then charge it fully prior to use if I get favourable temps colliding with my days off?? That way it stays in optimum charge while not in use( would these "partial charges" all count on a diagnostics as full charges??) ??
When I first introduced myself on here I was advised to keep the battery charged up and assume the poster meant fully....but this seems bad advice.
There really should be a booklet issued with Bosch equipped bikes to inform you of all this as sometimes it's like detective work finding stuff online....!
 

soundwave

Esteemed Pedelecer
May 23, 2015
16,189
6,319
well i used to charge them up to 4 bars if not going to be using them as the last bar is for balancing all the cells to fully charged.

tho now i just charge them fully and try to drain 2-3 bars a week and never had a problem ;)

these batts like to get used so best not left for more than 3 months as that is what the cells dont like.
 

Barrio Barranco

Esteemed Pedelecer
Nov 24, 2018
281
99
55
Cheers SW....Think I'll leave it on 3, took it down from fully charged tonight on a "turbo" blast in the dark. I've managed to get my Exposure Enduro light on the bar next to the display, not ideal on a tapering bar but it won't be put into deep storage, so it won't get forgotten about. But for all I know there may be snow in the next 3 months (hope not!!)and it'll be time to dig out the xc skis...
 

soundwave

Esteemed Pedelecer
May 23, 2015
16,189
6,319
with 18650 cells when fully charged they dont tend to lose much capacity if left and not used as got a fair few single cells i use for lights and flash lights and as long as there decent cells they will last just dont buy anything with fire on them as there cheap china fakes, just look on you tube ;)

storage charge for 18650s are 3.6v and max charged are 4.2v each. so 2-3 bars on the batt would be about that imo.DSC_0061_01.JPG
 

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