Starter battery (engine bay) flat after one night with just the fridge on level one.

[Gelertthedog]

This may have been covered in a previous thread, if so applogies, please point me in the right direction.
Anyway, a couple of times now without hook up and just having the fridge on lev 1 for a night Cali engine bay flat. Won’t start. Could this be leisure battery issue? Any suggestions?

 

[WelshGas]

This may have been covered in a previous thread, if so applogies, please point me in the right direction.
Anyway, a couple of times now without hook up and just having the fridge on lev 1 for a night Cali engine bay flat. Won’t start. Could this be leisure battery issue? Any suggestions?

The VW California has, from the factory, 2 x 75 amp AGM batteries, which power the roof, fridge, diesel parking heater and rear lights.
The engine battery does not power any of the above habitation equipment.
However, if you have a full electric sliding door or use the built in entertainment system a lot you can flatten the Engine battery.

What voltage reading are you seeing on the Control Panel? This only shows the Leisure Batteries voltage.

 

[Gelertthedog]

Thanks for reply. It’s a T5, no electric slide door. I do have a USB double charger in the dash which, last night had a magnetic base charge bay (for torch) but no torch connected last night. I don’t know if when leisure battery’s are duff (one or the other which powers the fridge) will it look for next power source ie engine bay battery and use the flatten that? Had the van 2019, not changed or tested the leisure battery’s ever, it has all worked off grid before though.

 

[WelshGas]

Thanks for reply. It’s a T5, no electric slide door. I do have a USB double charger in the dash which, last night had a magnetic base charge bay (for torch) but no torch connected last night. I don’t know if when leisure battery’s are duff (one or the other which powers the fridge) will it look for next power source ie engine bay battery and use the flatten that? Had the van 2019, not changed or tested the leisure battery’s ever, it has all worked off grid before though.

Engine battery only connected to leisure battery circuit when engine and hence alternator is running to charge leisure batteries while driving.

Unless the USB charger has an Off switch then it will be consuming power when plugged in even if it is not charging anything.

 

[Azteccamper]

The VW California has, from the factory, 2 x 75 amp AGM batteries, which power the roof, fridge, diesel parking heater and rear lights.
The engine battery does not power any of the above habitation equipment.
However, if you have a full electric sliding door or use the built in entertainment system a lot you can flatten the Engine battery.

What voltage reading are you seeing on the Control Panel? This only shows the Leisure Batteries voltage.

As an aside @WelshGas do I have to disconnect engine battery whilst I change roof sensors? Or is just the leisure battery under passenger seat?
Sorry to nip on on this thread.

 

[Gelertthedog]

Ok. Get that, however the usb is always plugged and not an issue if the fridge is off. It’s only when fridge or heater etc are in use without ehu the starter battery fails. I guess a leisure battery heath check is required either way.

 

[vbk1975]

As an aside @WelshGas do I have to disconnect engine battery whilst I change roof sensors? Or is just the leisure battery under passenger seat?
Sorry to nip on on this thread.

Pull the two Roof ECU fuses and will be sufficient. I advised that all the batteries should be disconnected, but now I understand more about the system, the two roof ECU fuses will do.

 

[Azteccamper]

Pull the two Roof ECU fuses and will be sufficient. I advised that all the batteries should be disconnected, but now I understand more about the system, the two roof ECU fuses will do.

Sorry but I thought there was just the one 30A fuse under passenger seat? Where are the 2 x roof ECU fuses please? Thanks again for your input and help.

 

[flying banana]

My starter battery died very suddenly and wouldn't hold charge for 1 night. Once it starts failing they go quickly and battery testers volt meters etc still show the battery as good ,but it isnt. Mines 2016. Changed it myself for 132 quid and then got a code man to code it.

 

[vbk1975]

Sorry but I thought there was just the one 30A fuse under passenger seat? Where are the 2 x roof ECU fuses please? Thanks again for your input and help.

For T6 - Roof ECU (not control panel)

Ign feed is fuse SC55 this also feeds the control panel E153 (T32b/32) as well.
Perm feed from Fuse SH17

 

[Meoncoast]

Same experience as @flying banana

 

[WelshGas]

Ok. Get that, however the usb is always plugged and not an issue if the fridge is off. It’s only when fridge or heater etc are in use without ehu the starter battery fails. I guess a leisure battery heath check is required either way.

On some T5/T5.1 it has been found that on EHU when the Leisure Batteries are full then the Engine battery receives a trickle charge.
This may explain why , when on EHU, the engine battery is fine and when not on EHU the engine battery is flattened . Nothing to do with the Leisure batteries which may be failing but is coincidental. More likely engine battery has failed.

 

[Azteccamper]

For T6 - Roof ECU (not control panel)

Ign feed is fuse SC55 this also feeds the control panel E153 (T32b/32) as well.
Perm feed from Fuse SH17

Brilliant. Thanks for your help @Lambeth Cali and @vbk1975 - 2 yrs ago charged £750+ by VW to change 2 sensors. Did the back 2 sensors today for £36 (sensors) and £25 on some tools.

 

[GreatResigner]

I have found that when my T5 SE has been left standing for a while the engine battery depletes fast. I have had an aftemarket (Sony) receiver fitted recently and I am wondering whether this is the culprit. The engine battery responds to a charge up (by alternator or battery charger) and seems to hold charge, after testing with a multi-metre.

 

[Grumposaur68]

Everything forward of the front seats use engine battery.
Everything rear of the front seats use leisure battery.

 

[vbk1975]

I have found that when my T5 SE has been left standing for a while the engine battery depletes fast. I have had an aftemarket (Sony) receiver fitted recently and I am wondering whether this is the culprit. The engine battery responds to a charge up (by alternator or battery charger) and seems to hold charge, after testing with a multi-

I have found that when my T5 SE has been left standing for a while the engine battery depletes fast. I have had an aftemarket (Sony) receiver fitted recently and I am wondering whether this is the culprit. The engine battery responds to a charge up (by alternator or battery charger) and seems to hold charge, after testing with a multi-metre.

It is worth checking that the power feeds are the correct way around. Most aftermarket radios have a low power permanent feed that keeps the clock and settings memory active but the rest of the radio is powered with a switched feed. A common issue is for those two to be the wrong way around and the radio remains fully powered all the time. (Even although it my appear off)

 

[TwoDogs]

Everything forward of the front seats use engine battery.
Everything rear of the front seats use leisure battery.

This isn't necessarily true on 5/5.1s