Some of the more sophistocated charging systems like the dualpro and the many others out there, do the job just fine. That is, if you have the bucks, the space and technical knowhow to install these systems correctly. Anyone looking into an on-board charging system would do well to look at the "StayNCharge". Simple to install, very cost effective and very little space required. A side bonus is that no heat is generated - ever. Check out the web site and become an informed consumer. I just installed one on my new Crestliner and couldn't be more happy. Their customer service is beyond words.