Can a flat engine battery affect the leisure batteries?

[iowflute]

I had a flat engine battery after not using it for 3 weeks and had a new one put in last week. Now my leisure batteries which are only 6 months old are saying 8.5v and 0% on the central console. I’ve got solar power 100w and the solar display is also showing an exclamation mark! Do I need to reset something somewhere? Can a flat engine battery mess up the leisure batteries?

 

[WelshGas]

I had a flat engine battery after not using it for 3 weeks and had a new one put in last week. Now my leisure batteries which are only 6 months old are saying 8.5v and 0% on the central console. I’ve got solar power 100w and the solar display is also showing an exclamation mark! Do I need to reset something somewhere? Can a flat engine battery mess up the leisure batteries?

As far as I am aware, no.
Was the Engine Battery the original or some years old?
If not it should last more than 3 weeks?

When was the last time the Leisure Batteries were showing a Full Charge?

You can try a reset of the Control Panel and check for any Control Panel Diagnostic Codes.
Press L lower button. Wait 30 secs and press L lower button again.

Check Control Panel Diagnostics.


Control panel On

Press and Hold R lower button and then press Control Knob for 5 secs.

New Hidden Menu . Scroll to VW Diagnostics.

If there are any codes shown, take note and then Reset/Clear.

Return to Main Menu.

Switch Off Control Panel using L lower button. Wait 30 secs and Switch On.

 

[sidepod]

I had a flat engine battery after not using it for 3 weeks and had a new one put in last week. Now my leisure batteries which are only 6 months old are saying 8.5v and 0% on the central console. I’ve got solar power 100w and the solar display is also showing an exclamation mark! Do I need to reset something somewhere? Can a flat engine battery mess up the leisure batteries?

No

 

[iowflute]

As far as I am aware, no.
Was the Engine Battery the original or some years old?
If not it should last more than 3 weeks?

When was the last time the Leisure Batteries were showing a Full Charge?

You can try a reset of the Control Panel and check for any Control Panel Diagnostic Codes.
Press L lower button. Wait 30 secs and press L lower button again.

Check Control Panel Diagnostics.


Control panel On

Press and Hold R lower button and then press Control Knob for 5 secs.

New Hidden Menu . Scroll to VW Diagnostics.

If there are any codes shown, take note and then Reset/Clear.

Return to Main Menu.

Switch Off Control Panel using L lower button. Wait 30 secs and Switch On.

I’m not sure if the battery was original but on a 2006 Cali I doubt it! The leisure batteries were showing full when I used it in November. Then in December, nothing on engine battery and leisure batteries only showing 30%. I drove it for about 45 miles today. I live on the Isle of Wight so limited to how far I can go. This didn’t charge the leisure batteries. I’ll try the reset of control panel tomorrow. Taking it for mot in the morning. Thanks for advice.

 

[iowflute]

As far as I am aware, no.
Was the Engine Battery the original or some years old?
If not it should last more than 3 weeks?

When was the last time the Leisure Batteries were showing a Full Charge?

You can try a reset of the Control Panel and check for any Control Panel Diagnostic Codes.
Press L lower button. Wait 30 secs and press L lower button again.

Check Control Panel Diagnostics.


Control panel On

Press and Hold R lower button and then press Control Knob for 5 secs.

New Hidden Menu . Scroll to VW Diagnostics.

If there are any codes shown, take note and then Reset/Clear.

Return to Main Menu.

Switch Off Control Panel using L lower button. Wait 30 secs and Switch On.

I’ve tried what you said to reset control panel and check diagnostic codes but there is no hidden menu on mine. The control panel is not even turning on now without the engine turned on. Something is obviously draining them as it shows 18amp, dropping to 12amp being using when the engine is running! Only 0.2amp when engine is off. I’m taking it to the friend who fitted the leisure batteries so he can test them and see if he can work out what’s draining them.

 

[WelshGas]

I’ve tried what you said to reset control panel and check diagnostic codes but there is no hidden menu on mine. The control panel is not even turning on now without the engine turned on. Something is obviously draining them as it shows 18amp, dropping to 12amp being using when the engine is running! Only 0.2amp when engine is off. I’m taking it to the friend who fitted the leisure batteries so he can test them and see if he can work out what’s draining them.

I would agree. There is something seriously wrong that needs looking at. Hope it's an easy fix.

 

[sidepod]

18A???????

 

[WelshGas]

18A???????

I think thats the Alternator charge of + 18amps. Indicates the Leisure batteries are pretty low.

 

[WelshGas]

I’ve tried what you said to reset control panel and check diagnostic codes but there is no hidden menu on mine. The control panel is not even turning on now without the engine turned on. Something is obviously draining them as it shows 18amp, dropping to 12amp being using when the engine is running! Only 0.2amp when engine is off. I’m taking it to the friend who fitted the leisure batteries so he can test them and see if he can work out what’s draining them.

Get your friend to check the 50 amp fuses on top of the Leisure battery + Post on the rear battery. You could be just running on 1 battery only if that has blown. It can easily be blown if not known about when changing batteries.

 

[Loz]

I’ve tried what you said to reset control panel and check diagnostic codes but there is no hidden menu on mine. The control panel is not even turning on now without the engine turned on. Something is obviously draining them as it shows 18amp, dropping to 12amp being using when the engine is running! Only 0.2amp when engine is off. I’m taking it to the friend who fitted the leisure batteries so he can test them and see if he can work out what’s draining them.

Alternatoer is not charging if you are seeing current flowing out like that, This happens if the bluemotion tech idles the alternator.

here is mine doing it yesterday just after I took it off Hookup.

 

[iowflute]

Alternatoer is not charging if you are seeing current flowing out like that, This happens if the bluemotion tech idles the alternator.

here is mine doing it yesterday just after I took it off Hookup.
View attachment 29377

Ah. No blue motion as it’s a 2006 Cali but the current is dropping off rapidly when the engine is running.

 

[Loz]

Ah. No blue motion as it’s a 2006 Cali but the current is dropping off rapidly when the engine is running.

Alternator or Alternator fuse possibly, do you see any voltage rise with the engine running?

 

[sidepod]

I’m still confused as to what is pulling 18A from the leisure bats on s 2006 unit?

 

[Loz]

Yea, that’s a lot..

Here is something to try, if you know where the big (80A?) fuse is for the split charge. (Not familiar with the 2006) then remove this and do your test again. If it is still drawing, its not flowing over to the engine battery and the drain is on the leisure side.
If the drain stops then you need to check the alternator.

 

[WelshGas]

I think thats the Alternator charge of + 18amps. Indicates the Leisure batteries are pretty low.

Ah now I see the picture. I don't believe the Fridge or Parking Heater tend to draw that much current normally.
As @Loz says, Isolate the Engine Electrical System from the Leisure system. Remove the Large 80amp fuse, in normally a Brown Fuse Holder , separate to the block of fuses, under the Front Passenger Seat.

 

[sidepod]

Agreed. It can’t be a leisure load as the fridge/heater fuses won’t stand that load.