I would seriously investigate your engine
. Odds are high that it is pretty wimpy in real world charging
capability. If you have room for a large frame alternator
it will make a big difference in main engine charging
time. I found a unit from a bus that will put out an honest 160 amps all day if needed. I made my own brackets but had to buy a couple of pulleys and have less than $500 in the upgrade.
Whether it makes sense to do this or put that money
into more solar
is something to be considered.