Is it Knackered?

KREW2

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I have a bank of 2x110ah leisure batteries. After launch I used the ship's radio and it signaled that the battery was low.
I know that one could be dragging down the voltage of the other as both were only showing 12.25 volts.
So I took one home and charged it in my garage for 24 hours, after two hours the voltage settled at 12.70.
I connected a 12 watt bulb and it shone brightly for 48 hours. I let the battery settle down again for two hours and had 12.1 volts.
Is it knackered?
 
I have a bank of 2x110ah leisure batteries. After launch I used the ship's radio and it signaled that the battery was low.
I know that one could be dragging down the voltage of the other as both were only showing 12.25 volts.
So I took one home and charged it in my garage for 24 hours, after two hours the voltage settled at 12.70.
I connected a 12 watt bulb and it shone brightly for 48 hours. I let the battery settle down again for two hours and had 12.1 volts.
Is it knackered?

Take the batteries to a battery supplier or garage that has a conductance tester
 
I have a bank of 2x110ah leisure batteries. After launch I used the ship's radio and it signaled that the battery was low.
I know that one could be dragging down the voltage of the other as both were only showing 12.25 volts.
So I took one home and charged it in my garage for 24 hours, after two hours the voltage settled at 12.70.
I connected a 12 watt bulb and it shone brightly for 48 hours. I let the battery settle down again for two hours and had 12.1 volts.
Is it knackered?
Spyros calcs show you have depleted the battery by half approx. The general concensus is that they only give out half their nominal amp hourage, so it looks about right
S
 
I had thought of that, but was told that it is not a good test for leisure batteries.

That is true to an extent because leisure batteries tend not to have a CCA rating that measurements can be compared to. You can compare two batteries of the same type though, if you can get a new or newer one even better. You need a CCA of at least 250A for starting small diesels, not that you should be using batteries not designed for starting.
 
Thanks for the tips all.
Yes, I will now fully charge the battery I have at home, take the other one off, and do the same test at home.
For starting I now have an Odyssey PC1100 Extreme Racing 40, fitted just before launch. Prior to this both my leisure batteries were divided into a bank of two through a 1, 2, both switch
Number one was always used for starting. Now they are connected in parallel it's possible that battery one is not so good, and sapping the power out of battery two.
 
Thanks for the tips all.
Yes, I will now fully charge the battery I have at home, take the other one off, and do the same test at home.
For starting I now have an Odyssey PC1100 Extreme Racing 40, fitted just before launch. Prior to this both my leisure batteries were divided into a bank of two through a 1, 2, both switch
Number one was always used for starting. Now they are connected in parallel it's possible that battery one is not so good, and sapping the power out of battery two.

Ideally if it is not too late leave the 1,2,both switch in for the domestic or service batteries. Have the new starter battery and fit a VSR. The 1,2,both switch woulod normally be used on both ie both batteries in parallel but making it easy to divide to compare one battery with the other or to quarantine one if you want. Batteries are normally fine in parallel but not when they get old or one dies. good luck olewill
 
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