Thread: D3 battery

Originally Posted by shack

So that was measured by nanocom, also another obd2 device, and 2 separate auxiliary plug testers.

I can confirm though that it only ramps up to that if the starting battery is somewhat down.

This makes me think we may need to reassess our use of the fridge as it is on 24/7 and is probably causing daily 15.5 volt charge events....or we might just wear it, it's really handy...

I wonder if what you see and what I see are related to different batteries? If a battery is capable of absorbing all the potential charge an alternator can deliver (low enough internal resistance) then you'll never see voltages that high as long as the battery isn't fully charged. On the other hand, a more conventional (or aged) lead acid which can't absorb the charge as rapidly will see its terminal voltage rise as it can't sink what the alternator can deliver.

Of course the other option is my alternator isn't capable of delivering the rated current. Damn, now I'm going to have to get hold of a DC clamp with enough headroom to actually measure it.

Originally Posted by PeterOZ

My D3 only gets 13.7v to 13.8V

Thats all mine gets to , both the old alternator and the new 1 I fitted 2 weeks ago.

Bulletman

Originally Posted by shack

If that is correct your alternator is on the way out unfortunately.

Cheers
James

its reasonably new

Originally Posted by PeterOZ

its reasonably new

I think your battery will gradually go flat/lose capacity(quicker than normal)..a form of shopping trolley syndrome.

Mr Drivesafe might pop along shortly and tell us all that I'm wrong!
But would be good to clear it up either way.

Cheers
James

[QUOTE=shack;2973997]Arrived a bit late to the party on this one.

One issue I've considered with running an AGM start battery on a D3, is that they charge at about 15.5 volts for some time after start, and most AGM specs suggest not to charge over 14.4 or 14.6.
Optima specs used to state 13.8, that had now changed took 15 volts.

I've never seen my D3 charge over 14.7 volts, and certainly never at 15.5.

Hi folks, and first off, other than for a very short period after starting, you should not be seeing 15+v with a Calcium/Calcium type starting battery.


In cold climate countries, during the winter months, you will see constant 15+v. We do not get that cold here, so again, constant 15+v is NOT GOOD for your cranking battery.


If you have an AGM starting battery, you should never see anything above 14.7v, even with a low battery.


Those with high operating voltages, can you try a hard reset and see if it lowers the “constant” operating voltage.


As for Optima Yellowtops, they can be fully charged with as little as 13.65v but will tolerate constant voltages up o 15.0v.


The Redtops and Bluetops can be charged with as little as 13.3v, up to 15.0v

Originally Posted by drivesafe

Hi folks, and first off, other than for a very short period after starting, you should not be seeing 15+v with a Calcium/Calcium type starting battery.


In cold climate countries, during the winter months, you will see constant 15+v. We do not get that cold here, so again, constant 15+v is NOT GOOD for your cranking battery.


If you have an AGM starting battery, you should never see anything above 14.7v, even with a low battery.


Those with high operating voltages, can you try a hard reset and see if it lowers the “constant” operating voltage.


As for Optima Yellowtops, they can be fully charged with as little as 13.65v but will tolerate constant voltages up o 15.0v.


The Redtops and Bluetops can be charged with as little as 13.3v, up to 15.0v

Ok, I'll keep an eye on it but it hasn't got that high since putting in the new battery.

What about the guys that are only seeing 13.8 volts, is that an issue?

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

Cheers
James

I think all this talk is making my battery weak, jumped in to take kids to school and before i even cranked it i got the full gamut of dash lights and faults on the screen. 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, disconnected the aux. battery and got the main on charge while i went over and borrowed one from the old man.
Will see how it goes in the morning and will keep the spare in the back just in case, then i might be off down to supercharge for a new one.