Battery voltage.....

[richardjawilson]

Good afternoon all. I am checking my batteries and 1 of the pair is not holding charge that well. Would anyone know what my voltmeter should read on a battery that has been fully charged.

One is showing just over 13 volts after 24 hours charging whilst the other is only showing 11.04.


Thanks richard.

[Limey Linda]

Originally Posted by richardjawilson

Good afternoon all. I am checking my batteries and 1 of the pair is not holding charge that well. Would anyone know what my voltmeter should read on a battery that has been fully charged.

One is showing just over 13 volts after 24 hours charging whilst the other is only showing 11.04.


Thanks richard.

Looks like you have a duff battery. A good one should measure 12.5-12.8with no load. The fact that there is a difference is significant. Sorry, buy a new one.

[Limey Linda]

Originally Posted by richardjawilson

Good afternoon all. I am checking my batteries and 1 of the pair is not holding charge that well. Would anyone know what my voltmeter should read on a battery that has been fully charged.

One is showing just over 13 volts after 24 hours charging whilst the other is only showing 11.04.


Thanks richard.

Looks like you have a duff battery. A good one should measure 12.5-12.8with no load. However , maybe you have a bad connection, so measure directly across the terminals. The fact that there is a difference is significant. Sorry, buy a new one.

[ian parkes]

I find batteries that have just been on charge seem to read around 14.5 v and hold that for a while . Could be worth getting the other one checked

[doggypaddle]

sounds like a dead cell. 2.2 volts per cell is about right fully charged so 11 volts = 5 good cells one dead one.Look into the cells while its charging, they should be all gassing the same and look the same, pos plates chocolate brown and negatives slate grey.
you will probably find one cell either gassing more or less than the rest and the plates all grey and white, thats the dead un!
be careful not to wiggle the wires causing sparks or use a naked flame to look in the cells or you will get a dead eye too! battery gas is 2 parts hydrogen to one part oxygen, perfect stoichiometric mix for maximum bang!!
your other battery is likely OK if you get around 13.2 volts after its stood overnight after a thorough charging. you may get a false voltage when its come straight off charge 14-15V because of a phenomenon known as surface charge.

[richardjawilson]

Thanks for all your help. Have tested dodgy battery again and its down to 10.5v, so that one is for the bin. Other one is fine. Hopefully I will be out tomorrow afternoon for a quick spin !

regards richard