Battery LED's

Are you sure it is an LED emitting light? Some batteries have an optical device.

It is a hydrometer . green is fine, black is flat or knackered, white is knackered (no fluid touching it)

No, I'm not sure of that to be honest, it just looked like the usual small LEDs you can buy from maplin :-)

Aha, excellent information! You really are a very memorable character; thanks!

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "David R" saying something like:

That's not an LED, it's a Mintball. There to suck on when the battery lets you down.

It's not an LED but a coloured float.

Green means the charge state is ok. Black low and needs charging. Red, the battery needs replacing. Although a long slow charge may change red to green.

I have just removed the lens cover and examined it. It does not taste of mint, and has a rather similar effect to chilli-powder on the tongue. Where did you discover this was 'mint' flavoured? Must be different battery you've got.

Shouldn't that be an 'acid drop'? (if such things still exist...)

Battery is 5 years old, guess it'll be turning to red/white soonish...

I had one where no amount of charging or topping the cells (which were low when I got the car) would make it show a steady green, or anything in fact. But walloping the battery would make it bobble about greenly.

Only time that battery failed me was when the boot light decided to stay on - It must've been doing it for a while, but one very cold winter morning after not using the car for a couple of days there was next to no charge at all. Bought a new battery as I had to go out in a hurry, but after finding the drain (the new battery died under similar circumstances) and charging the old one, it performed flawlessly for months. I stopped using tyhe car, didn't fire it up for 3 weeks or so, and it turned and fired fine when I finally got round to flogging it.

So just how useful those floaty things really are, I don't know...

Agreed. Mine has not shown green for over 12 months. Still no sign of slow cranking even on cold mornings but checking with a DVM it's won't hold a charge above 12.4v and drops to around 12v after standing overnight so I guess it's living on borrowed time.