Ebike (lead acid) stored over winter in un heated garage question

ElbadoKing

10 mW
Joined
Oct 8, 2017
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I kept my ebike stored in my garage over the winter, charged the battery minimum once a month. When I first began to ride my ebike after the winter, the battery storage was horrible like 1 tenth the original storage. I went out yesterday and it seemed to be holding more power then the previous ride I had. My question is after a winter of being stored in a unheated garage being charged minimum once a month, does the battery go through some type of warm up period or is the low battery due to the colder weather during my previous ride?
 
Sorry to have to tell you that your lead is probably dead. I know that it is expensive but lithium ion is the way to go for bike batteries. Keep reading there are many threads about switching to lithium.
 
I wouldn't assume it was dead quite yet. Charging once a month should have kept the batteries from sulfating too much. Would have been more ideal to keep them on float, but once a month isn't too bad.

Lead Acid does suffer immensely under cold weather though (temporarily, unless the acid totally freezes), and what may have been happening is that there was still capacity in there, but due to the cold temps, the voltage was dropping too much and the low voltage safety was tripping.

Keep them on a float charge for a few days, and wait for a nice warm day to go for a ride to see if they are still any good.
 
If they were kept charged the freezing point is something like -60 c. I don’t believe it got that cold in Toronto this year. However batteries don’t like being cold hence the huge reduction in CCA in car batteries, even worse in the SLA batteries, try a few charge cycles and keep it plugged in if you have a smart charger. Ultimately your probably going to see a determination on a yearly basis with those batteries. If you swap to lithium you may want to try a way to make them removable over winter. I made my sidepanel hinged so I can get to my battery.
 
You could try charging/riding for about 3 cycles and see if it improves. If not, I wouldn't waste any more time on them.

Keeping them charged monthly and cold (but not cold enough to freeze them), should be near ideal storage conditions.
If there was some kind of parasitic load from the bike that drains them in less than a month, they will be toast.
 
Like a drowning victim, they are not dead till they are warm and dead. They should perk up a lot when its hitting 80F.

You did right in the storage, nothing you could have done would have been much better, assuming they were not getting any drain during that month, not plugged in, nor already dead from internal short circuits. ( lead inevitably develops sulfite dendrites, which when they touch, become a trickle short)

But lead is lead, and there is just no way they did not age over the winter, and lead simply times out fast used or not. So you will not have last years capacity. Those damn dendrites grow anyway, even when retarded by keeping the battery full.

If your current needs mean your range is too short now, good excuse to upgrade to lithium this spring. But if you only need 2-3 miles per charge, then you can squeeze quite a lot of time from tired old lead.
 
I took my ebike out a few times and the range is much better then my "after winter" ride. The range is still not what it was before the winter. I forgot to add before that I left the alarm armed during the winter. My next question is would the alarm be enough of a "parasite to cause battery damage?
 
ElbadoKing said:
I took my ebike out a few times and the range is much better then my "after winter" ride. The range is still not what it was before the winter. I forgot to add before that I left the alarm armed during the winter. My next question is would the alarm be enough of a "parasite to cause battery damage?
Yes. Even a controller connected but turned off can do it. If the drain is so small that the battery voltage never gets down the sulfation point it won't hurt but anytime the cell voltages get really low, sulfate starts to form.
 
Update I took all the advice you guys gave me went and went riding today. My ebike is running as well as it did last summer I think the desulfating with the charger did the trick. Thanks for the help everyone.
 
How did you desulfate the battery ? 12v can go to 14.6v but seats at 13.6v . So 13.6v is friendly. Don't let it get hot. It been a long time for me with series 12v sla. We use to only use a hydrometeor and had to pull same fluid up with the rubber tulip bulb. 45yrs ago.
sla like to be fully charged all the time or last longer keep that way. that's the reason for the rv trickle charger went parked.
 
I just rode it a few times and every time I charged kept it on the charger for long periods of time a few days to a week. I dont know if I desulfated the battery but id did something because my battery runs the way it did before the winter.
 
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