I got chills...

[WelshGas]

Check there are NO Diagnostic Fault Codes on the Control Panel.

Press Lower R Button and Control Knob - Hold until Menu changes. You will see an item VW Diagnostics. Scroll through. If there are any Diagnostic Codes registered then Delete.
Back to Main Menu - Press L Lower Button to switch off Control Panel. Wait 30 secs and then Press L Lower Button to switch Control Panel ON and reboot software.

 

[mchbiker]

Check there are NO Diagnostic Fault Codes on the Control Panel.

Press Lower R Button and Control Knob - Hold until Menu changes. You will see an item VW Diagnostics. Scroll through. If there are any Diagnostic Codes registered then Delete.
Back to Main Menu - Press L Lower Button to switch off Control Panel. Wait 30 secs and then Press L Lower Button to switch Control Panel ON and reboot software.

Thanks I'll have a look. Does anyone know what typical voltage is showing when the batteries exhausted and ready for charging?

 

[WelshGas]

See table.

 

[mchbiker]

See table.
View attachment 12529

Currently my display reads 12.4v 50%

 

[TwentyOneThirtyFive]

Stick it on hookup for a day. Not sure what the charge rate is for the modern cali, probably higher than mine. My charger is 9amp, so approx 17 hours to charge from flat in an ideal, lossless world.

You can get an adaptor for the hookup cable to domestic 3 pin plug.

Mine lives on hookup 24/7 when at home. Reads 14.4v when charging, 13.6 or 7 I think when fully charged with no load. As soon as you apply a load, ie. fridge or heater, the voltage will drop. This is normal.

Personally I'd ignore the percentage symbol (the Westy controller has something similar, in bars). No idea how it works it out other than guessing

 

[mchbiker]

Thanks for all the support and ideas. After a 4th dealer visit it's FIXED! I've asked for a full description of the cause so I can post it on here to help anyone else affected. Faulty component was affecting the information from batteries to overhead display, neither of those two areas were at fault.
I finally drove home with a big smile ready for some trip planning!