Will LiPo batteries deteriorate outside with the temperature changes due to day-night cycle?

Question

I am new to the hobby and I'm concerned about LiPo batteries. I live in an apartment (this is Europe, blocks of apartments are the norm in my country) so I can not put the batteries in a dedicated room or garage. Finding a spot in the house where I can put the LiPos 1 meter away from any flammable material seems impossible.

I do have, however, a convenient small balcony in which I could put a box with the batteries for safe(st) storage, something like a bat-safe, ammo or metal tool box, which have kind of proven they can withstand a LiPo fire; in a small plastic closet to protect them from rain insulating the metal box from the plastic closet with some drywall and maybe some sand.

The balcony does not receive direct sunlight, but temperatures vary from ~ 15C/59F (min) ~ 35C/95F (max) in summer and ~0C/32F (min) ~ 15C/59F in winter. Temperatures could very exceptionally reach a maximum of 45°C a couple of days at peak hours. From what I have read batteries can bare these ranges of temperatures without too much of a problem but, Will they suffer from the everyday variation of temperatures and humidity and will this increase the risk of them exploding?

The idea here is to maximize safety, I do not really care that much if their performance deteriorates or if I have to renew them more often, as long as this does not come with a higher risk.

Note: The batteries I have ordered are two AHTECH Infinity 4S 14.8V 1300mAh 85C Graphene.

Answer 1

The typical temperatures experienced across Europe shouldn't be a problem for LiPo storage; although depending on exactly where you are you may also want to check out this question: Do low temperatures damage LiPo batteries?

If your storage location may be subject to direct sun then this could cause extra heating which may be harmful - think of a dark colour car on a hot day. Having a light (e.g. white) box or keeping it in shade would help here.

Also, you do want to avoid condensation wherever possible as the moisture may cause corrosion or (if it pools/collects) may short the battery connectors. Many LiPo storage containers have vents to let pressure out if a battery fails and you don't want to seal these, so add the waterproof layer inside - something as simple as putting each battery in a zip-lock bag would work, for example.

Finally, storing the batteries at the appropriate storage charge level will help maximise their life wherever you store them - see At what voltage per cell should I store a LiPo?

Answer 2

The only thing I know that could damage the battery is extreme temperatures, and based on what you said I think that those temperatures are okay.

The difference in temperature between day and night shouldn't matter at all, since it is both a small and relatively slow change. I tried searching for some more information about this, but I couldn't find any unfortunately.

Answer 3

Will the batteries deteriorate? Yes. Will they deteriorate significantly? probably not.

Generally, LiPos are best kept in cooler temperatures and being stored in hot places can harm the battery cells. However, with the temperatures you gave, the deterioration should be minimal and it is definitely better to have the batteries deteriorate a little than to have them cause a fire in your apartment.

As far as maximizing safety, this seems like the best option. Another thing to consider to maximize safety is to storage charge them when you won't be using them.