A square back will help a lot, but the rest of the system has to be in good shape, too. Have you read the MAD article? Have you looked over your harness, and bulkhead connector?
How about the headlight harness? Do you run headlight relays, and what are you running for headlights?
And adding "more battery(s)" unless the one you have is completely inadequate, is no solution. SOMETHING has to charge it/ them back up!!!
So far as alternators, there are several ways to go. Hell, way back in the mid 70's I used to run a Delco integral unit on my 340 Landcruiser. This was before Al Gore invented the internet.
