In the Baltimore area of Maryland there are 3 reservoirs that are electric only and to obtain permits you can not have a gas motor at all.  There are Ray electric motors (and others) that make 48 and 60 volt electric motors cabible ofpuching an 18 foot boat all day very well.  

Normally they are used with 6 volt batteries (10 or 8 total) but why can't you use 12 volts and save the weight and space?  I know the 6 volt will last longer but how much longer.  There are several boats that use 2 12 volts on 80 lb Minn Kotas and zip along pretty well.  They also seem to last all day too.

So to any electrician, or battery guru, how much more run time will I get with 6 volts versus 12?

Also, does anyone have any experience with Minn Kota's new eletric motor?

Thanks

Fish MD the 6 volts will give you a little less then twice the run time.  The issue is that the bigger Ray motors draw 85 plus amps which will drain the 12 volt batteries very quickly.  They don't have the capacity that 6 volt batteries have.  You will not see much difference in the speed performance between the weight of 6 or twelve volt batteries.  After all most boats were not designed to be push  they were designed to run on top of the water, no electric is going to do that for you.  Since you can't plain the boat with electrics you are only going to go so fast, maybe 6-7 miles per hour tops.  What I am trying to say with all of this is to get the 6 volts you will be much happier in the end.

Tom D.