Recharging Liions in hot weather or heat waves

We've had a couple of exceptionally hot days in the last week when our thermometer in the shade has reached more than 45C (113F) at about 2pm in the afternoon.

I've always restricted myself to only charging at night in our hottest months, but I'm wondering if I may too fussy.

At what ambient temperature do you think it would be wise to avoid charging?

I do not have the definitive answer to this but for some perspective:
HKJ stops his battery tests once the battery reaches 100 degrees Celsius. I myself did a temperature test in a flashlight the other day in which the battery (a Samsung 30Q) repeatedly reached a temperature of 85 degrees without apparent damage to the performance.

So my guess is that the batteries will be alright. They may detoriate a bit faster at high temperatures, but on the other hand, they may not.

I stop my battery test at 80C today, I got too many melted holders at higher temperature (Even with my modified model).
But check the datasheet for a LiIon battery, the temperature is much more restricted during charge, usual a maximum ambient temp of 45C

Well it’s a battery, not a human that cools by sweating, so 45c vs 22c doesn’t affect cooling as much as you think. Unless you are charging so fast they barely survive on a 22c day, I doubt they heat up much more on a 45c day. But do monitor them until you trust them.

Last summer I charged cells in even numbers, put a 10*10cm copper sheet (1mm thick) on top of the cells and placed a bunch of CPU coolers on top of that, passive but it sure helped when I felt the cells
Also I placed the charger on a coolblock with the fins upwards so air can more easy reach the charger.

Hahaha we got it worse then Queensland so damn hot here. I went to my shed and my Polish had turned into liquid my petroleum jelly had melted. Also one of 18650 had fully drained to 0.7 volts! That could have been the light also. If the temp is 40 degrees outside i would think the shed may hit 60 its got a concrete floor and it colorbond steel.

So in other words we are taking over the kitchens to bake anodization, cook off paint, refrigerate cells :smiley: