Battery 12.49v OK?

[Sinky]

Hi
Found a battery in my lock up.

On the mutimeter it reads 12.49v

I'm sure Iv had in my Granada but just wouldnt start it?

Reads good to me but I'm just needing a second opinion please

[vitesse6]

its the cranking amps that start it ..not the volts ,it may read 12v but it doesnt mean the batts any good

[Sinky]

Yeah thats what I thought.Is it a bin job do you think?

[bortaf]

TBH you need to drop test it to see if it's any good, a decent battery will float (sit idle) at about 13V but the real test is under load, if it stays above 12V when loaded it's ok but it could well drop to 5 or 6 V under load, thats what a drop test does, loads the battery and measures the voltage under load.
On the bright side old batterys are fetching £5 to £10 a pop at the mo

[scaryoldcortina]

It might just need charging.... you could always try that

[Sinky]

ok thanks guys on charge now

[ejenner]

Halfords do a free battery test. Just bring the battery into your local store and ask them to test it. If it fails then you have the option to buy a new battery... hence, free test.

The reason it will sit at 12v like that is down to the fact that these batteries are always multi-cell. The little caps on the top tell you the number of cells. Once a cell fails the battery is unlikely to be able to start a car but will still show the voltage being produced by the other cells. Just if you try to draw heavy current it needs all the cells or else it won't give you enough.

There is something available called BattAid which can revive a battery which is on the turn. You need to add this with some battery top up water into the cells which have dried up. For a couple of quid you can get a battery going and working again. If it's too far gone then that trick won't work but the fact that the product is available tells you it works often enough to justify making the product.

[xbo11ox]

Just charge it up overnight and bosh it on your car, if it starts it great, if it doesnt its goosed.

[Sinky]

Ok 15hr charge now sitting at 13.5v.
Thinking about it I'm sure Iv tried it before on the car and there was not enough power to turn it over.
Ill just go and try it now and get back to you.
Thanks for all the advice by the way.

[Sinky]

All I get is the solinoid clicking. Stuck the lights on and metered = 10v and dropping rapaid
Batteries don't last long here cause of the heat.
You have to keep topping up.
I'm back in Scotland september so Ill try and pickup some Granville Batt Aid.

Does anybody have Grandville Bat Aid tablets?Do they have a hazardous cross on the packet?
If so I will not be able to carry as hand luggage

[chairchild]

A fully charged battery will sit at around 12.8v - a dead battery is anything below 12.2v

After you've charged a battery (at no more than 14v, 14.5v only being acceptable for a brief amount of time) it will have a "surface charge", whereby it shows a higher voltage, but doesn't have the current capacity to maintain that voltage once it's applied to a circuit


As for your battery, it sounds knackered. No amount of tablets/chemicals will help a dead battery

[bortaf]

Here's a tip i learnt the hard way, NEVER leave a battery on the bare griound the cold will kill the charge in a few days, that's why batterys usually die in the winter, the cold is hardest on them, as the acid freezes and thickens the electrons don't flow as easyly or sumink and the voltage drops, i've seen a new battery killed in a week due to being on the floor in a garage, i allways put em on some polystyrene (sp?)
i assume the opposit is true cos if you put dead batterys in a warm place they get some life back in em

[Kai]

You can try rejuvenating it with fresh acid and distilled. Desulphating the plates might also help, while you're at it.

[Ads 19]

i started my clear out my batterys, managed to find 45 that wouldn't spark a bit of wire across terminals. £390 now i'm sure i could have tried to fix some with nice charge, but at that price hardly seems worth hassle

[ejenner]

I thought I had too many, think I've only got around 5 dead batteries lying around. Actually some of them might be good, typically removed from cars which had no trouble starting.