Battery charger doesn't work when too cold?

[Piers Finlayson]

I cracked open an el cheapo cordless power tool set at the weekend. I put an uncharged battery into the charger an after a few seconds the charger indicated charging was complete. The battery was still uncharged. I then tried with the other battery and got the same problem.

I tried again today, this time using the charger inside the house instead of an unheated outbuilding. Initially I got the same problem so rang the service center up and they said the charger must be faulty and they'd send a new one.

However, after a few hours - now the charger has come up to room temperature (from around freezing) - it seems to be working fine and charging the batteries

Have others experienced this, or does it sound like a fault? There's no operating temperature in the instructions, although the charger does say for indoor use only (and I'd claim my outbuilding is still indoors!).

Thanks, Piers

[R D S]

Assuming the batteries are also near freezing, they will appear to charge but depending on type need need to be at least 5-10 deg C.

[Alan]

In message , Piers Finlayson wrote

The components themselves in your charger should work at 0C or below however you can get condensation forming on the exposed electronics causing a short or resistive path between components or component connections. Brining the charger into a room at 20/25C would have dried out the moisture and allowed it to work again.

[Dave Baker]

Google as usual answers most problems.

[Dave Plowman (News)]

Typical Ni-Cad behaviour. Useless at low temperatures. Think Li-Ion may be ok.

[The Medway Handyman]

Highjacking this thread, I've noticed my LED torch doesn't seem to light up when cold - e.g. left in the van overnight, but lights up after a while in the warm.

Do LED's do this or do I just have a duff torch?

[ransley]

Im sure the manual would have informed you it was out of range, mine does. LiIon will be ruined trying that.

[Dave Liquorice]

The LEDs don't care about the cold but the battery does. Some fail completely around or below 0C but recover when warmed back up. Others also fail and lose all their charge as well. Lithium based battery technology does best in the cold.

[Piers Finlayson]

As I said, the manual does not indicate any operating temperature for any of the equipment.

[The Natural Philosopher]

Plenty of kit is so badly designed that it fails to work at quite small deviations from 'room temperatures'

If its a nickel fast charger, its rather critical ..they work by detecting a voltage drop that indicates the pack is as full as it can be got.

If the kit itself is heating up enough to fool the sensing that the voltage has dropped, it might well terminate early.

[MuMu]

It is not the charger. It is the battery which won't take charge at low temperatures.

M. Moorthi

[The Medway Handyman]

Yes of course. It has bog standard AAA's in it, I wonder what temp they stop working at?

[Dave Liquorice]

Most batteries give up or become seriously impaired near or below 0C.

[Rod]

Didn't Ice Station Zebra go on and on about NiFe batteries and low temperatures? (Must be well over 30 years since I read that.)

[sparky2]

Some fast chargers measure the battery volts first and if it's zero assume the battery is a dud and won't try to charge it. The battery needs to be trickle charged a small amount to get the volts up then it will fast charge.

J