Thread: D3 battery

Originally Posted by shack

And would I be correct then that the 15 volts is bad news for an AGM?

The vast majority of AGM cranking batteries can not tolerate voltages greater than 14.7v, so yes you are correct.

Originally Posted by loanrangie

Got home and both batteries at 12.5-12.6 but i when i go to start it the volts drop to 11.51 on the GAP tool

While the cranking voltage is fine, if the 12.5-12.6v is immediately after turning your motor off, they should have been over 13.0v.

On the other hand, if that’s the voltage of the batteries a few hours after turning the motor off, than they are near fully charged.

Originally Posted by Tombie

810 CCA
150 RC

Vs

SSB SS88TI
1180 CCA
250 RC

Big difference in stored energy

I agree, but I am not happy how quickly the storage capacity of that very same ssb diminished!

And there is also a premium on that extra capacity. It was impressive when new, for maybe the first 12 months.

Again I may have had a dodgy one, and we are pretty hardcore operators due to circumstance, still disappointing though, as I now realise it's been failing for many months based on how the car is now cranking.

Cheers
James

Agree 100%. They’re pretty heavy on batteries, many get only around 2 years if they don’t supplement charging monthly.

Circumstances of use really can pull them down hard.

Originally Posted by drivesafe

While the cranking voltage is fine, if the 12.5-12.6v is immediately after turning your motor off, they should have been over 13.0v.

On the other hand, if that’s the voltage of the batteries a few hours after turning the motor off, than they are near fully charged.

That is after sitting all day, 11.51V just turning key to ignition without cranking. Appears my multi meter has carked it so maybe those readings are wrong, 11.51V is as shown on my GAP tool.

Originally Posted by loanrangie

That is after sitting all day, 11.51V just turning key to ignition without cranking. Appears my multi meter has carked it so maybe those readings are wrong, 11.51V is as shown on my GAP tool.

Not sure those readings are that reliable.

At 11.5v you would normally be right on the border of not being able to start your motor.

Did you have any trouble starting it with that voltage reading?

I wouldn't have thought it would drop that much just after sitting for a few hours. Doesn't sound right. If mine did that I'd be concerned.

Originally Posted by drivesafe

Not sure those readings are that reliable.

At 11.5v you would normally be right on the border of not being able to start your motor.

Did you have any trouble starting it with that voltage reading?

None at all but i'm getting all errors/faults normally associated with low voltage, after it stop ****ing down i swapped batteries but the one i swapped in was only 610cca and 100AH but i wanted to see how it would go. I did a quick run around the block 50-80kph and it was fine, stopped and restarted and back to the errors/faults. I have a feeling my aux. was propping up the dying main, not labels on the genuine LR Exide to tell me how old it is but it was at least 1 year old prior to my ownership so nearly 4yo old.
I dont have another correct size battery to test unless i can borrow the one out of my brothers Merc which is about the right size.