flat battery

[John B]

Hi chaps looking for some advice again if you'd be so kind , the last two mornings my battery has not been able to start my motor so today I've given it a good charge and the battery now gas 12.6 v and with the engine running I'm getting 14.2v does this sound about right to you ?? Cheers

 

[jims-terrano]

Voltages seem ok to me. Check that the battery cables are firmly fixed to the terminal clamps as over time the strands inside the cables break.
Also the starter motor can also give symptoms like that when it's on it's way out.

Careful when disconnecting battery charger, make sure it's turned off first so that you don't get sparks as these can cause an explosion due to the gases given off when charging.

 

[solarman216]

A good battery fully charged and stood for a few hours should read 12.8, and 14 .2 with engine running is good, but 12.6 is lowish for a full charge, so suggest it is on its way out, unless you have something stealing your power, Rick

 

[John B]

Thankyou chaps I'll test it in the morning to see if it loosing charge. Just had a look at my recipts and this battery is 2 and a half years old just thought it should last a bit longer than that ?

 

[jims-terrano]

Generally they do last longer in my experience but you do get some that won't. You could also try leaving battery disconnected over night to prove nothing is draining it.

 

[solarman216]

age is not a guide, how it has been treated is, if it has been flattened to below 11.5 volts then every time that happens capacity is dramatically reduced, like wise a car that is hard to start will shorten the batteries life, Rick

 

[John B]

Ok cheers chaps :thumb2

 

[glanrichbex]

Open only the bonnet, turn everything off and close all the doors.

Disconnect a terminal from the battery and connect a 12v bulb ( a small wattage like a courtesy light bulb is ideal ) across the clamp you have just taken off and the battery terminal you removed it from.

If the bulb lights at all, it shows that current is being drawn by something on the vehicle and this could be sufficient enough to run the battery down.

 

[Paff]

If it is a sealed battery, then there should be a little window to display the condition, should be green not black. Or if you have the screw tops to top out, remove them and try to start the motor, look at the cells as you do (you may need someone to help) and see if any cells bubble. Bubbles = battery no good. Or get a garage to pop on a discharge meter.

Just replaced my battery and it was a cell.

 

[macabethiel]

Battery Life ?

Thankyou chaps I'll test it in the morning to see if it loosing charge. Just had a look at my recipts and this battery is 2 and a half years old just thought it should last a bit longer than that ?

Most modern batteries last 5 years or more that said I had a Bosch on my Mini and it packed up in just over 2years with a dead cell. An unbranded battery on our Merc lasted 10 years.

The battery on out Terrano had a 2 year warranty and expired just short of 3 years. I had a Carlton for 7 years and the sealed battery was never replaced.

I think it's a bit like people some live to a 100 others expire early!

 

[John B]

Just had the battery tested and the machine said Bad and replace so I'm off down halfords for a look about armed with my trade card :doh

 

[Banshee]

Try Batterybay mate in Cannock, they are dirt cheap and 3 years no quibble warranty

 

[John B]

63 bucks from Eurocarparts with three year warranty so not bad

 

[rustic]

This table I find is a good guide to understanding how good a battery is.
It must be in a rested condition, not being charged and not being discharged for say half an hour.
The state of charge is for what is available on the battery, it does not show you it's capacity, or capability for Cold Cranking Amps. (CCA)
Even though the battery shows a good voltage, it could be sulphated up and unable to produce any current.