Fed up of always worrying about power in my first two vans I installed a 230ah underseat lithium battery and a btob along with a battery master to maintain hab battery when not being used, no solar required. Everything works really well, the only potential problem is that I have never seen the lithium drop below 70%, although its a long time since the novelty wore off and I rarely look at the app now. I usually do not stay more than one night and the btob recharges on the subsequent drive. I would say 60% of the time I am off grid, however, if there is a site near by or a CCP then I happily use them, once again no battery draw as I use their leccy if included. I don't in any way regret fitting lithium as it has taken all worry about hab power away, I am worried that it may be harming the battery.