Thread: How long could I leave my D4 without driving it

My RRS battery is now over 7 years old and on a day to day basis the car only gets driven the 1.5km to the shops and back every second day - long runs maybe once a month - so the battery rarely gets time to charge up.

On cold Canberra mornings (-4 this morning) the battery reads 11.8 to 12v with ignition on accessory - so no computers on. Switch the ignition on and the battery drops to 11.4v but the car starts first go everytime and the radio works fine and is not in power saving mode.

When driving the 1.5km the alt is charging up to 14.8v - I know when the battery is fully charged this will drop back to 12.5v and then varies depending on load.

This highlights the voltage in the system can drop quite low and not impact the operation of the car.

This has reminded me to put the car on the smart charger to get battery capacity back up even though its level is not affecting operation.

I was expecting the battery to die this winter but is still going strong.

Garry

Originally Posted by garrycol

I was expecting the battery to die this winter but is still going strong.

Garry

Silly boy!!!

You know Murphy is always listening!

Regards
Trevor

Originally Posted by garrycol

When driving the 1.5km the alt is charging up to 14.8v - I know when the battery is fully charged this will drop back to 12.5v and then varies depending on load.

Gary, would that only be a surface charge ? 1.5km won't get it up to full charge I would guess. That's my argument about the the alternator not giving batteries a deep charge.

Regular Battery charger use is the key to help maintain the starter.

Brett.....

Originally Posted by drivesafe

Hi Richard and this would explain most but not all the reason for your batteries being a little lower than expected.

Even with the SC80 and unused for a month, your batteries should have been around the 12.0v because once the SC80 turns off ( at 12.0v ) it will only be drawing about 5ma from then on.

So at 11.8v, which is not that low, but it does show the batteries were not in top condition, close to it.

The Optima particularly, should have been at at 12.0v and the cranking battery at at least 11.9v, so again, that’s not that low.

BTW was it cold when your measured the voltage, as this will drop battery voltage readings?

Tim
I am from Canberra so not cold it is bloody freezing
It is possible my meter is not 100% accurate
As mentioned above I have the anti rust gadget
Which would use some power

Both batteries appeared about the same voltage so may be the cut out had not occurred
I will have to check what cut out value is set

In future I will leave the charger on or disconnect the negative leads

Richard

Hi again Richard and with cold temperatures at the time of the voltage readings, I would say your batteries are fine, and while needing a charge, they were well within the expected voltage range for batteries that have been unused for a month.

You have nothing to worry about.