While I never had an issue of the battery going flat, the "crimp fix" raised my running voltage by almost a full volt (from a questionable 12.9 to a more healthy 13.7). I didn't solder it, but rather cut the factory crimp out and used a new butt connector.
There's a great tutorial with pictures at vmaxoutlaw.com. Click the "tech info" and scroll down to electrical.
Also, Max's don't seem to like cheapo wal mart batteries, and if they do they don't last very long, like a season at most. Odyssey batteries are a VMF favorite(mil spec gel cell batteries), though there is one made by Panasonic that's about half the price some users have had good luck with. Sean(one2dmax) also has a mod to install a slightly larger battery for extra capacity.
I run the Odyssey, did the crimp fix, and installed a manual fan switch to keep temperatures down, I've never had an issue with slow cranking or a dead battery.