Leisure battery drain after starter battery replacement

[Pete M]

Hi All.
I replaced the leisure batteries at the start of last summer and had a full summer use and all good.
Replaced the starter battery a couple of months ago (didn’t code it after conversations on here) but I have noticed the leisure battery charge has been poor when checking, van is driven every day but we have been away for 4 days so it has been sat on the drive and got in it today and zero % on the over head control.
Drove for a few miles to the shops and switch off, battery saying 100% very briefly but watched it countdown to 30%.
Control panel saying 13.7v >>20.0a whilst ticking over…
Any idea please what’s going on?

 

[WelshGas]

Hi All.
I replaced the leisure batteries at the start of last summer and had a full summer use and all good.
Replaced the starter battery a couple of months ago (didn’t code it after conversations on here) but I have noticed the leisure battery charge has been poor when checking, van is driven every day but we have been away for 4 days so it has been sat on the drive and got in it today and zero % on the over head control.
Drove for a few miles to the shops and switch off, battery saying 100% very briefly but watched it countdown to 30%.
Control panel saying 13.7v >>20.0a whilst ticking over…
Any idea please what’s going on?

Ignore the % reading. What is the Voltage and amps, 30 mins often Ignition Off?

 

[Pete M]

Ignore the % reading. What is the Voltage and amps, 30 mins often Ignition Off?

I’ll nip out check after 30 mins, thanks again WG for the on going help over the years, much appreciated… there should be Genius members that have a free membership given the amount they help out

 

[Pete M]

After a 25 mile drive to work this morning it is reading as per the image, now 3 hours later it is showing 40% 12v 0.2a

 

[WelshGas]

After a 25 mile dive to work this morning it is ready as per the image, not 3 hours later it is showing 40% 12v 0.2a

View attachment 144483

That's a lower voltage than I would expect. The -0.2amps is as expected with the screen on .
It would be worth checking the voltage of each leisure battery with a multimeter with the red lead disconnected and insulated from any metalwork and also check the 75amp cube fuse on the rear battery for continuity.
It is not impossible for 1 battery to be faulty.

 

[Pete M]

That's a lower voltage than I would expect. The -0.2amps is as expected with the screen on .
It would be worth checking the voltage of each leisure battery with a multimeter with the red lead disconnected and insulated from any metalwork and also check the 75amp cube fuse on the rear battery for continuity.
It is not impossible for 1 battery to be faulty.

Ah okay, so it it not possible for the starter battery to have an affect on this as they were fine before the new starter battery was installed and as mentioned earlier they were new June last year
Is there only one fuse at the rear battery and not one on the front one under the seat?

 

[WelshGas]

Ah okay, so it it not possible for the starter battery to have an affect on this as they were fine before the new starter battery was installed and as mentioned earlier they were new June last year
Is there only one fuse at the rear battery and not one on the front one under the seat?

Just the one Cube Fuse. If
it blows, and it is prone to blowing then you are using just 1 leisure battery as the rear is disconnected.
VW also recommend the vehicle is plugged into EHU monthly for at least 12hrs to keep leisure batteries in good condition as that will charge them to a true 100% capacity whereas driving tops out at 80% charging from engine although the Control Panel will probably show 100% but this calculation is a bit iffy, but not the voltage.

 

[Pete M]

No big fuse in the rear compartment but one under the passenger seat (80a light orange colour) which is okay, disconnected the + from the rear battery and both are saying 12.2v so not sure how to proceed so any advice is much appreciated
Had the new starter battery coded today and now start/stop works so as a heads it looks like driving for a while and not blowing the ring to recode new battery issue not necessarily the way forward.

 

[WelshGas]

No big fuse in the rear compartment but one under the passenger seat (80a light orange colour) which is okay, disconnected the + from the rear battery and both are saying 12.2v so not sure how to proceed so any advice is much appreciated
Had the new starter battery coded today and now start/stop works so as a heads it looks like driving for a while and not blowing the ring to recode new battery issue not necessarily the way forward.

The brown 80 amp fuse is for alternator charging. There should be a 75 amp Cube fuse on the rear battery +tve.

 

[Pete M]

Ah okay, I didn’t know what a cube fuse was just assumed it was a big fuse of some sort but google imaged it and now understand
I’ll check it tomorrow because I’ve put it all back together now but both front and rear are at approximately 12.2v so guessing there isn’t a dead battery?