Lithium battery storage in off season - where to store?

[Pauly D]

Hi,

Winterized our trailer yesterday and I'm about to pull the 2 lithium batteries. I was thinking to store them in a bedroom closet inside our cottage, but we do use the cottage on weekends through the winter and all bedrooms get used. I believe lithium needs to have ventilation for safety (as in the trailer). Is a bedroom closet ok to store them? I can't put them in the garage because it's unheated and those inside temps could reach -20C through winter. The basement workroom in our home in the city is another option, but that would mean lugging the batteries to and from.

Any thoughts?

Thanks,
Paul

[rubicon327]

A tempered or heated space will be all they need. They don’t need ventilation.

[0210]

+1 to the above.

Any space that will be above freezing the entire winter. Lithium batteries will get damaged if they freeze. They don't need any special ventilation. I wouldn't put them in a vacuum-sealed bag, but any closet will be fine.

Personally, I would keep them as close to an exterior exit as possible, and far away from bedrooms. This is for the simple reason that batteries - all batteries - can suffer from defects and in the worst case can catch fire. Lithium fires cannot be put out with water, and can burn for literally DAYS. The closer the battery is to an "exit," the higher the possibility of you being able to use a piece of wood (or whatever non-conductive item you have on hand) to push it outside your home.

I don't mean to scare anyone; the chances of that happening are very, very slim. But they are non-zero, and similarly apply to all of our electronics (phones, laptops, etc.)... most of which we happily keep on a bedside table.

Personally I've had a MacBook battery swell to the point that the laptop had a huge bulge on the bottom. I noticed it in time, shut the laptop off, placed it outside my home and called Apple; they replaced it under warranty (even thought it was beyond the warranty period). At one time Samsung phones had a problem with them catching fire. Things can happen.

[alanmalk]

Originally Posted by 0210

+1 to the above.

Any space that will be above freezing the entire winter. Lithium batteries will get damaged if they freeze.
...

The manufacture of the battery should provide the minimum storage temperature. Mine were specified at -20F and over the winter here in Denver we reached -17F one night. Fingers crossed, they worked fine this year. The trailer is parked outside and the battery compartment in the E'21 is under the interior seat. I did add an inch of insulation along the outside walls of the compartment just for insurance.

[Pauly D]

Thanks for all your thoughts folks. Our two lithiums are now safely stored in a warm area for winter. We are babying these babies for their first winter in Manitoba. Cheers, Paul

[MyronL]

What purpose does that serve? My 19 with solar on the roof and having one Battleborn battery connected in the tongue box, with trailer being under cover outside for the last 3 years, has been just fine. In winter we do get pretty cold here. I don't understand the logic of removing lithium batteries for the winter.

[0210]

Originally Posted by MyronL

What purpose does that serve? My 19 with solar on the roof and having one Battleborn battery connected in the tongue box, with trailer being under cover outside for the last 3 years, has been just fine. In winter we do get pretty cold here. I don't understand the logic of removing lithium batteries for the winter.

They can freeze, internal components get damaged, you can lose 70-80% of battery capacity.

Lots of information like this:
- https://www6.slac.stanford.edu/news/...ng-performance
- https://www.relionbattery.com/knowle...n-cold-weather

Similar literature came with my own batteries.

[rubicon327]

Originally Posted by 0210

… you can lose 70-80% of battery capacity.

Maybe lead acid. Lithium will lose some capacity at cold temps but no where near that much. The batteries warm up with use so they have potential to recover some of those “lost” amp-hours. The biggest limitation is not charging below freezing but most lithium batteries have low temp protection or at least they should in an RV application.

[MyronL]

Think I am good. Copied from the Battleborn website:
"Our batteries can handle a storage range of –15 degrees Fahrenheit to upwards of 140 degrees Fahrenheit."

[rubicon327]

Originally Posted by MyronL

Think I am good. Copied from the Battleborn website:
"Our batteries can handle a storage range of –15 degrees Fahrenheit to upwards of 140 degrees Fahrenheit."

You are fine. Ideally the batteries would be charged and then disconnected from any charging source or loads. They only drop a few percent per month. Lithiums don’t like being kept at full charge all the time like lead acid. Better to let them discharge naturally a bit if storing for several months.

[SageRpod]

Originally Posted by MyronL

Think I am good. Copied from the Battleborn website:
"Our batteries can handle a storage range of –15 degrees Fahrenheit to upwards of 140 degrees Fahrenheit."

Same here. Ours have integrated heating as well.

[MyronL]

Inside the tongue box. (190W solar on roof, wired to controller, plus additional wiring ready for 100W portable solar panels.) It has a lid.

[Pauly D]

Originally Posted by MyronL

What purpose does that serve? My 19 with solar on the roof and having one Battleborn battery connected in the tongue box, with trailer being under cover outside for the last 3 years, has been just fine. In winter we do get pretty cold here. I don't understand the logic of removing lithium batteries for the winter.

From what I've read on this forum, including ETI's recommendations, the lithiums shouldn't be left out in freezing. Temps in my area are often below -30C through winter. My batteries might be ok, they might not. Logic is we spent a bunch, we're hoping they'll last as long as possible. Easy to remove. 4 bolts, 13 mm socket. Once I realized the plastic housing had enough give, I could easily maneuver them out. (I thought at first I might have to remove the bench seat - easy with 4 screws - but that wasn't necessary.) The biggest joy was how light these things are!

[MyronL]

Yep, it's a good thing for you lithiums don't weigh so much.

[John in Santa Cruz]

Lithium's can not be CHARGED if the battery internal temps are 32F or below. My SOK batteries say they can be discharged (provide power) when they are as cold as -22F, that's also the lower storage temp.

The batteries with internal heaters, those heaters only work when charging power is connected to the battery and the battery is too cold... the internal BMS will divert the charging power to the heater elements until the battery is warm enough to be charged.

[Pauly D]

Originally Posted by MyronL

Yep, it's a good thing for you lithiums don't weigh so much.

You can say that again. And have handles for added convenience.

[dunnet]

I will be taking the batteries out of our trailer, what is the best procedure to disconnect the wiring?

[John in Santa Cruz]

Originally Posted by dunnet

I will be taking the batteries out of our trailer, what is the best procedure to disconnect the wiring?

unplug shore power. If you have solar, switch off the solar charge controller if you can. Disconnect main leads to battery negative, disconnect main leads to battery positive, disconnect the series cable if you have two golf cart batts, remove batteries one at a time. if you have GC2 Golf cart batteries, there's a strap with hooks that fit in those square tabs for lifting the battery out, makes it 100X easier (GC2 batts are like 60 or 70 lbs each). you can often borrow one from a battery store. example: https://www.ebay.com/itm/304410897758