We moved to Victoria (Australia) just as COVID was ramping up and this state has had quite a strict and lengthy lockdown which has worked. After being limited to travel within just 5km of home, that was lifted to 25km and now the state is open. I took up a kind offer from old friend Richard who has recently purchased a property in Drummond. Naturally, being a considerate guest, I slept in the van.
The van has been parked under cover for some time and a few days ago I discovered that, despite taking it for a weekly drive, the deep cycle "house" battery was very flat. It was showing 3V and at that low voltage the relay which connects it to the alternator had, correctly, declined to do that. I should have noticed.
Something must have been draining the battery slowly even though everything was off. Happily after a slow charge it doesn't seem to be too damaged.
It was sunny both days and the battery quickly charged and was able to run the fridge over night without any trouble.
I have read that connecting the house battery suddenly to the car's alternator isn't as gentle on it as being charged from solar through a charge controller so for now I'm parking it in a sunny spot and have disconnected the alternator relay.
Speaking of solar.. Richard's place is completely off grid and has an impressive solar system built over many years back to a time when panels were so expensive that it made sense to have them steered to follow the sun.