I would like to store my Lipos in an unheated garage for the winter. To protect from freezing, I thought I would put them in a large cooler (or small fridge) with a heater. Bird-bath heaters have a temperature setting of 35 or 40 F. Could I bury one of those in a layer of sand at the bottom of the cooler? Ammo case(s) could go on top of that. Or are there better thermostatically controlled heaters for this application?

David

Do you keep your I-pad, I-phone, and all the rest of your Lipo battery operated devices in the house or in the garage? People don't realize that many of the devises we use and store in our homes have Lipo batteries in them.

Discharge your Lipos to the storage voltage and put them in a metal box and keep them inside. Yes, these batteries can be a fire issue if treated improperly and most of the fires caused by these batteries are because of improper handling. Lipos are not handgernades or sticks of dynamite, Treat them properly and they will serve you well.

Mine spend the winter in the "crisper" drawer in my refrigerator.

Originally Posted by tacx

Do you keep your I-pad, I-phone, and all the rest of your Lipo battery operated devices in the house or in the garage? People don't realize that many of the devises we use and store in our homes have Lipo batteries in them.

Discharge your Lipos to the storage voltage and put them in a metal box and keep them inside. Yes, these batteries can be a fire issue if treated improperly and most of the fires caused by these batteries are because of improper handling. Lipos are not handgernades or sticks of dynamite, Treat them properly and they will serve you well.

+1

People get way over concerned with the risk of fire. If you treat your batteries right your risk of a lipo fire is no higher then most other risks of fire in your home. Also you will find 99.9% of lipo fires happen during charging or because while being moved a connection broke and shorted out. A battery sitting still in a box doing nothing has a 0.00001% chance of bursting into flames randomly.

Well, right at the top of this topic is the sticky post "Lipo Fires Are Real". A little worrying for someone just getting back into the RC world. As to laptops and other household lipos, I trust Apple's quality control a little more than I do some of the RC brands. And it's not just my house: If I caused a fire with a Lipo, my wife would kill me.

But your words are reassuring...

Just curious - why are you concerned about the batteries freezing?

Also - why would you want them heated?

A tech-support person at Thunder Power wrote me this:

"...40 degrees is the lowest temperature is the lowest you want to store
the battery at and definitely don't want the battery to freeze and the
highest temperature is 70-77 degrees ideal room temperature."

I realize that batteries not charging or flying VERY rarely give trouble, but I am a little OCD, so for peace of mind I thought to keep them in the garage. Small refrigerator in the summer (it gets hot in there), and small heater in winter. As I said, the bird-bath deicer only turns on at 35 degrees, so it would be on very little.

A freind of mine keeps his batts in a metal box and puts the metal box in his fireplace. It is a natural fireplace and he has glass doors on it. He cracks the damper slightly. If a battery goes bad it is not only in a safe place but the fumes will go up the chimny.

Originally Posted by midnite

Just curious - why are you concerned about the batteries freezing?

Also - why would you want them heated?

Lithium batteries die when they are frozen.

Originally Posted by grimbeaver

Lithium batteries die when they are frozen.

But, but, but they rarely puff up when frozen.
Rick.

yes, there is a sticky called "Lipo fires are real".

We could also have stickies called:

1. Gas furnace fires are real.

2. Gas stove fires are real.

3. Gas hot water tank fires are real.

4. Clothes dryer fires are real. This is a biggy!

5. Bar-B-que fires are real.

And on and on and on.

You could have a sticky on just about a thousand things that could catch fire. Are you getting rid of these things in your home? No. Why? Because most of us properly maintain these things. It's no different with lipos. Treat them properly and you should not have a problem.

Can you be gauranteed you will not have a battery go bad? No, No more than you have a gaurantee that all those other things will not go bad.

Fair enough. But I take similar precautions where I can with all the things on your list. I've already admitted to being compulsive in wanting to store them in the garage. Given that, my question is still "What's a good way to do it?"

Originally Posted by grimbeaver

Lithium batteries die when they are frozen.

I'd like to hear a little more about that. Where does that information come from?

They don't contain water so how does cold affect them? Is it just that the chemical reaction is slower and will return to normal when brought back to warm temps or is there actually permanent damage to lithium batteries when in temps below water freezing level?

There are cars now using lithium batteries. What do they do when temperatures fall below the freezing level of water? As far as I'm aware, there is no precaution against storing these cars in low temperatures.

I've flown in temperatures considerably colder than 32 degrees F. No problems.

By the way, even refrigerators have temps lower than 40 degrees and people routinely store their batteries there without concern.
I think this is only about a degradation in performance while the batteries are cold. When returning to warm temps they recover as any battery would. It's about chemical reactions slowing in cold temperatures, nothing more - but I could be mistaken - willing to hear and learn more.

Freezing doesn't hurt them in the least. My 5 cell 5000 ma batts stay in the garage all winter, most of the time well below freezing. This is the fifth year for some of them and they still work fine.

Gord.

Originally Posted by flypaper 2

Freezing doesn't hurt them in the least. My 5 cell 5000 ma batts stay in the garage all winter, most of the time well below freezing. This is the fifth year for some of them and they still work fine.

Gord.

The freezing point of water and the freezing point of a Li Battery are not the same, needs to be quite a bit colder for a LiPo. But if you freeze them there is a good chance crystals will pierce the membrane that separates anode and cathode, then when they warm up again you have a short.

Usually nothing dangerous happens, but the lipo will be toast. AFAIK this is around -15-20C.