I'm installing 4 6v deep cycle batteries in my PM with a 3000 watt Freedom Marine inverter. My plan is to put them inside behind the drivers seat but am concerned about the gases. I am going to put a Fantastic Fan in the roof over the battery area that can vent while charging or equalizing but I'm concerned that the gases can be ignited by the fan as it's sucking the fumes past it. I guess the best way would be to box the batteries in and vent it through a baffle out through the side of the van but I'm not too thrilled about cutting another hole in the body. Any thoughts?