Battery Dying

[AndyD]

Ok, been a long day and brain is frazzled so need someone to verify my thoughts or tell me I'm barking up the wrong tree....

Been having issues with slow cranking and what I presumed is a battery drain but I now think my battery is on its way out.

Output from alternator is 14.2v.
Battery after overnight charge is giving an output of 11.9v.
Been out in the car for a 2 hour run, no lights or heater fan on just radio and after parking and switching off battery is reading 10.8v.

Going to leave it overnight and check again in the morning and see what the output is in the morning and if it drops I will take it off and recharge again and then leave it off and see if it continues to drop volts if it does it's the battery if it doesn't then I'm guessing I have a battery drain somewhere.

Does this makes sense or shall I have a cold one and rethink my approach?

Ta.... Andy

[Fat Audi 80]

Your battery is ****ed and won't take a charge. (How old is it?)

[AndyD]

Your battery is ****ed and won't take a charge. (How old is it?)

Thanks, that's what I was thinking but didn't want to spend more cash if my presumption was wrong. Battery is only 2 years old BUT it's been used very little since being bought as the car was laid up.

Many thanks
Andy

[Fat Audi 80]

How many times has the battery been allowed to fully discharge? I killed a battery in a couple of years by allowing it to fully discharge a couple of times only. Modern batteries don't like being flat.

[david1980]

if the batterys been standing on floor or the like it will discharge and kill it put it on a bit of wood when not on the car

[AndyD]

How many times has the battery been allowed to fully discharge? I killed a battery in a couple of years by allowing it to fully discharge a couple of times only. Modern batteries don't like being flat.

I think that's been the issue to be honest, it's been discharged a few times over the last couple of years and even had about 3 months when it was flat when I forgot to replug my trickle charger back in...

[AndyD]

if the batterys been standing on floor or the like it will discharge and kill it put it on a bit of wood when not on the car

Good info, didn't know that......It was sat on a plastic box off the floor (by chance and not by planning) but I think it's been the lack of use that's killed it....

[AndyD]

Well bit the bullet and popped into ECP today and picked up a nice shiny new battery. It has certainly made a difference to it starting while warm so let's see if it solves the problem completely.

Cheers folks

[denniselbows]

A bit more info about battery's . When a battery is discharged the water and acid separate and the acid will attack the lead plates. So if left discharged for a week or more the plate can sulphar up and cristalise which once this has happened that part of the plate is dead causing less cranking amps and a lose in performance and you won't get that back by charging up. So always keep a battery charged if possible . Another thing always keep the top clean and dry as if there's a bit of dirt or wetness it will cause voltage to leak across the top which I'll also drain the battery down .