What did you do to your Patrol today!

[Cuppa]

I expect that the 400w solar setup is there for long term static touring rather than a clunky backup to the 300amp alternator. 150ah a day from solar is a great delivery for most things I'd have thought. Way more than I have and plenty for most requirements.

I appreciate the concern over the capacity for the batteries to accept the 300amps for sure. They really need to be connected in series and the full bank getbtue full 300ampd as a shared load I reckon. There is so much supply that I see No reason ever to isolate all 300amps to a single battery.

My expectation of the solar matches yours MR, I only mentioned it as a 'clunky alternative to re-charging a 400Ah battery bank if it had been severely depleted by winching use, if the 300A alternator were not used. It could be a 3 day job. I can't see what connecting the 400Ah batteries in series would achieve - it would not increase the stored capacity, only the voltage (although this would allow for smaller connecting cables). The need for current regulation of a 300Amp alternator feeding into the 400AH battery ban would remain surely. The reason I suggested the possible need to have the 300A alternator only switched through to the 400Ah battery bank was in the absence of any means of regulating the output in normal circumstances when winch9ng was not occurring. I didn't suggest (I dont think) that it should be connected to a single battery, (Ie the crank battery) as this would have pretty much the same issue. What I did suggest was a two alternator setup, with the 300A one restricted to winch use only, unless there were some means of regulating it's current output.

I don't understand your comment about a shared load - shared with what?

It is all conjecture on my part. If you have a 300A alternator, or know of others who do, charging lead based battery banks of less than say 1200Ah how is yours (or theirs) set up? Maybe I am imagining a problem which doesn't exist?

To be honest the more I think about it the more I think a change of battery type to LiFePo4 is probably the best, albeit rather expensive, solution.