Solar-rechargeable batteries

Are you sure it's the batteries? I ask because in the past I've found those solar-powered garden lights to be pretty useless over the winter months: not enough sunshine to charge the batteries. OK, so the days are getting longer now, with potentially more sunshine, and things should be improving, but it's worth asking the question.

They tend to die a horrible death in winter when our weak light short days ensure they spend far too long flat and miserably wet and cold. Same mode of failure destroys solar powered "please go round the bend" active signs on frosty winters mornings when they might do some good.

You really only need to choose NiCad vs NiMH based on what was in the unit originally. It is worth giving the "dead" batteries a recharge on a modern smart charger just in case it can get them going again, but daily cycling to absolutely flat will takes its toll. Its a very hard life on the batteries in one of those garden lights.

I tend to put ones in them that are already past their best (and also to alter the switch on light level so that it is more appropriate to UK slow summer sunsets of our latitude rather a tropical fast sunset).

NiMh do not like being flattened. NiCd is much more tolerant.

Before you buy anything, take the batteries out and look for corrosion on the terminals and on the battery contact points. I've got loads of these things and I'd say that 3 out 5 have been rescued by cleaning them. For some reason it always seems to be the positive terminal of the battery that has the green muck on it.

You can get low capacity (no point getting high cap as they wont have time to charge up) rechargeable quite cheaply. One web site is here

(never used this seller its just a random search)

Basic chemistry ... copper at the anode.

Ahhh, I've always wondered. Thanks. I left skool 50 years ago at the age of 15, this sort of thing was not taught.

That's more expensive than the low self discharge 2100 mah ones are in lidl.

The lidl Tronic NiMHs used to be good I have a couple of dozen of them, but now they are utter s**te, about half their rated capacity, they feel like they're inflated with helium, they're so light.

Poundland are 2 for £1 for AA NiMH.

NT