on-board dc alternator charger

anyone ever run something like this?

http://www.cabelas.com/product/Minn...&Ntt=charger&WTz_l=Header;Search-All+Products

I use a 12v non-digital 55lb thrust electric for trolling in the morning and then run my 1982 mariner 2 stroke 150hp motor all afternoon for tubing/skiing, looking to recharge my 2 trolling motor batteries with the main motor so I can troll for a few hrs in the evening again with the electric before heading home for the day, searched KFF and I couldn't find anything about setting up/success with on-board dc alternator chargers, I don't know much about charging systems and I'm wondering if this charger is compatible with my motor and if so is it difficult to set up, any advice would be appreciated

I don't know how well that works but I installed a battery selector switch between my two deep cycle batteries so I can run on one until it gets low then switch to a full battery. I have always been told not to connect your engine battery system to deep cycle trolling batteries in any situation.