You'll have to make sure that you keep it adequately charged so your lead acid battery doesn't get sulfation problems. This means the resting voltage needs to stay above 12.5V or 12.6V, I forget, but you'll want to look that up. Lead acid batteries are best stored at 100% charge to avoid these issues. Ideally, this means at the end of each trip your battery is fully charged (as it would be with an active alternator). However, the guys running without an alternator usually plug in daily.
Here is some additional info on sulfation:
Sulfation and How to Prevent it - Battery University