Hi all,

I appreciate there are a number of battery related topics here, however I'm unable to determine whether I have a drain or my battery is rubbish!

So, used the car on a long journey 5 days ago, so battery should have been fully charged and showing 12.6v immediately after I turned it off.

Put a voltmeter over it this morning and now showing 11.4v. Draw on negative cable showing 0.18amps.

Thoughts?

And if replacing battery, are you going for Varta units?

Cheers,

CB 2007 RR Vogue SE TDV8
2003 RR Vogue TD6

Is the drain of 0.18A on the earth after the car has fully gone to sleep ie after about 20minutes?

The drain was on earth just after unlocking the car which had been sat unused for hours. 2007 RR Vogue SE TDV8
2003 RR Vogue TD6

You need to measure the drain appr 20 minutes after you've locked the car - or closed all doors. You can do this by stripping the bonnet sensor so that you can open the bonnet without the alarm going off. Imo you should try to sort out any drain before replacing battery.
I investigated quite a lot (measured the different circuits / fuses) to find the source of the drain in our ffrr - drain now fixed after replacing the FSR and the BT module.

When you open the car quite a few ecu's switch on which is the current you are probably measuring.
You need to open the bonnet and leave it open then lock the car and wait for it to go to sleep and then measure the current on the earth cable. You may have to put a brick on the bonnet switch to close it

^+1 too slow

Last edited by nicedayforit on 25th Nov 2016 2:01pm. Edited 1 time in total

OK.

What are your thoughts on the battery dropping over 5 days without use? 2007 RR Vogue SE TDV8
2003 RR Vogue TD6

Your car probably has a minimal drain anything up to 30mA, so your battery will show a small drop in voltage after 7 days.
Mine manages about 14days and then shows a drop of about 0.1V which I can live with.

Makes sense, so dropping 1.4v in 5 days is probably saying the battery isnt holding charge and needs replacing? 2007 RR Vogue SE TDV8
2003 RR Vogue TD6

Could be the battery but could also be a battery drain.
It's worth checking for battery drain correctly before buying a new battery.
Have you tried measuring for any current in your alternator positive cable to the battery positive terminal with the ignition off.
There shouldn't be any current.

OK will do. I've just tried to start the car (batt 11.7v) and nothing at all - whats the min voltage for start? 2007 RR Vogue SE TDV8
2003 RR Vogue TD6

One thing to consider when you open the car the battery voltage will drop, particularly if you have the radio on. You really need to wait with the door open until everything shuts down and the battery voltage recovers to a stable reading to measure it.
Having said that you are not going to have much success in starting with 11.7V. I've had mine start with it reading 12V in summer, never tried it in this weather.
Bear in mind if you allow the glow plugs to heat before trying to start your voltage will drop. I tend to not bother waiting for the glow plugs to heat even in winter.
At the end of the day you will probably change the battery and keep your fingers crossed, I would instead of faffing about in this weather.