As long as your routinely don't draw the batteries down to a low level then slowly put juice back in, then draw them down, etc. It will work, of course, over a day -- I just think it causes issues.

I had a friend with lead acid batteries that had an issue with the controller on his unit and he boiled-over the batteries. He had a French unit (don't remember the name) on his "new" Beneteau that didn't like the charge rate near his drawdown with his refrigeration. Ultimately, we got him into gel cells which were didn't have that problem -- but they got sulfated. Then he replaced his unit. His charger was supposed to be "smart", but then like Lake Woebegone (wear all of the children are above average), it wasn't that "smart" ;^))).

The way to check the charger's real output capacity is to put into a load demand that should produce "full" output. Let the charger run a bit and monitor what the actual amperage output is. In a post above, you might check-out my response to Brian's post.