Battery storage question

[lucian]

In the past I've always just pulled the 30 amp fuse and put a trickle charge on them once a month or so though the winter in my unheated garage. This cold snap has me wondering if I should pull them out and bring them down in my basement where it stays 62 degrees f all winter.  I was always under the belief that if the batteries stay charged that they wouldn't freeze, but is it better or necessary bring them in when it gets this frigid ?  Rather not pull three batteries if it's really not necessary.  TIA  dave

[Tom]

AGM, acid or Lipo???

[lucian]

Lead acid on two, not sure on the third. I'll have to have a peak at it.   Thank's Tom

[Tom]

Lead acid with the temps you're getting.  I'd say probably best to pull them and put in the basement.  Check this out for your lead acid batteries.  There are some temp. tips.  2nd link is for agm batteries.

http://usbattery.com/winter-storage-maintenance-tips-flooded-lead-acid-batteries/

https://www.batterystuff.com/blog/agm-battery-best-practices.html

[lucian]

Thank''s  again Tom, good info.  I think I'll pull em out, certainly can't hurt right?  Excuse to clean up the posts and hideout in the garage for a bit.

[fotoguzzi]

I remember someone telling me not to put it on the cement floor in the basement, don't remember the reason tho. but yeah I'd bring them in.. how cold is it there? gonna be -12f here tonight and a high of 3 below tomorrow.

[Kiwi_Roy]

I know at about -40 a car battery will freeze but I wasn't sure about a discharged battery so I googled it

This is what I found on Google
At a 40% state of charge, electrolyte will freeze if the temperature drops to approximately -16 degrees F. When a battery is fully charged the electrolyte will not freeze until the temperature drops to approximately -92 degrees F.

[rider33]

as long as the battery is kept charged you shouldn't have a problem.  The easiest way to do that is to keep it on a smart charger (Battery Tender or equivalent) all the time.  Hook up an SAE plug to the battery (handy for a variety of things like heated vests or phone chargers by the way) & just plug it in when not riding.  The problem with manually charging is if you forget and the charge drops low enough it can freeze and crack the case leaving you with battery acid everywhere which is no fun at all to deal with.

[lucian]

Another question for the electron wizzard's.  I am going to pull all three batteries and bring them inside the basement.  Can I hook all three together in parallel and use one tender on the bunch?  We used to store golf cart batteries this way. Suspender snap.

[Wayne Orwig]

Chemical processes slow down in cold. So, the battery is actually preserved so to speak, in the cold. Leave it out in the cold. BUT, you need to keep it charged so it does not freeze (or sulfate). And at some point, as someone mentioned, it will freeze even if charged. In Ohio I always left batteries in the outdoor shed, charged. So how cold are you expecting it to be?

You can parallel batteries that are identical. If there is much variation between the batteries, you should not parallel them

[lucian]

Thank you Wayne,  when you say the same , do you mean battery type or of similar charge?  The garage will typically not be below -10 f for more than a month or two tops.

[Lumpy Idle]

I remember someone telling me not to put it on the cement floor in the basement, don't remember the reason tho. but yeah I'd bring them in.. how cold is it there? gonna be -12f here tonight and a high of 3 below tomorrow.

just as an aside:

there is an old husband's tale that putting a battery directly onto the ground will cause it lose its charge. this is not true but the myth persists.

[rider33]

I believe because they way a smart charger works is to constantly read the battery & adjust the output according to need, wiring several together might give it a false reading.  I use multiple tenders tho they do make multi-bike models for that purpose.

And on another front: the freeze point of a battery is dependent on both the charge and the temp.  If the charge drops low enough it does not need to be exptemely cold for problems to develop.   Oddly, high temps can be a problem too, tho not interms of freezing :)

[Wayne Orwig]

Thank you Wayne,  when you say the same , do you mean battery type or of similar charge?  The garage will typically not be below -10 f for more than a month or two tops.

Even batteries that are the same model, but significantly different ages, should not be charged in parallel. A smart charger may overcharge one battery while undercharging another.
Good reason to rotate the charger from battery to battery each weekend or two.

-10F, I would leave in the bikes IF they are kept charged.