Grand California roof bed

[Wondering Star]

If on a hook up it's not a problem as the main starter battery will receive some charge, also when we wild camp the alarm is not set when in the van.
To be honest your biggest concern will be the leisure battery. On my last trip to the lakes our two 95 amp hr AGM's lasted 2/3 days and that's with 200watt of solar.
In the UK any camping in the winter months will be compromised and you will need hook up.
You could consider upgrading the batteries to lithium but at a cost and possible wiring upgrading, lithium 95 amp hr battery £1200 ish.
If you want to wild camp and not be reliant on hook up a considerable investment is needed.
Check out the new Winnebago EKKO camper to be launched shorty in the State's and you will see how to be self sufficient in power and water.
The majority of European vans are not really suited to all year off grid camping.
I tend to listen to music through my phone and blue tooth mini speaker, generators tend to be noisy even the so called quite ones and some sites may not allow use.
I plan to keep my set up standard for now but for next winter I will fit two lithium batteries but I don't expect much change out of 3k

 

[Wondering Star]

I'm not sure about the phone, but when I viewed the fix on YouTube it was suggested to only remove one of the two wires to allow other features to work.
When I get round to doing mine I will test phone operation.
Expensive sound system with appalling sound quality!