Anybody changed a PIV to carry 4 batteries?

The question is why ? Unless youre fishing alot of current i wouldnt bother, but rather run two group 31s instead on a 24v system. If you really need to go with the 36v you will need a plate across the bilge area forward of the seat post(covering the pumps) to place your oil tank on. I think youll also need to move the starting battery rearward a tad as well(this is from memory), but measure to be sure, and there youll have it. Good luck, D.

Buddy of Mine has his P4 set up with 4 batteries, It is a tight fit but he has all three located on the Port side next to his saddle tanks and the crankin battery next to the Oil resevoir, so It can be done, Though I believe he is runnin group 27s not 31s. I have a three battery system and fish tidal currents, I have seen times where a 36v troller (100 lb+) might be more ideal. If just fishing lakes and resevoirs then, just go with two 31 series for the troller and youll be fine. Other option which is what alot of guys run is to rig the 36v toller to all three batteries (includes your crankin battery)