the Peukert Constant. Yup, been there, cheated with that, but it doesn't really solve the problem. I find that usually shore power will rectify the problem in a matter of hours too, but it has taken as long as two days on shore power. I think that's because I have two chargers and only one is 'on the system'. The other, takes longer.
My 'good' charger died and as been replaced but I'm not usuing it as much until I get used to it and move back aboard for the summer. It seems that Mastervolt no longer makes a charger compatible with my monitor and inverter So now, they don't 'talk' to each other. They watch each other but don't talk. According to Mastervolt I'd have to replace everything with the new network system! Cool. Not. Seems like most marine manufacturers think they have figured out that if they just make new stuff every few years that's not backwards compatible, we'lll 'have' to buy all new systems more often.
Now you know why my 'next' boat will be comfy but really, really simple. (btw, Simple means to me that each system stands alone and that the boat can be cruised comfortably without needing special connections and printed circuit boards and that I have the capability to fashion my own many of my own parts or substitute readily available, common parts for critical systems, i.e. plumbing/heat/sail handling)