On Mon, 29 Jun 2009 04:07:42 -0500, Rick Morel
wrote:

On Mon, 29 Jun 2009 00:34:08 +0000, Larry wrote:

My equations only showed the futility of using battery powered electric
drives compared to an outboard motor, nothing more. They were never meant
to be mathematically correct.

I was trying to point out the obvious and discourage him from this electric
nonsense when what he really needs is an old single cylinder 2-stroke and a
2 gallon gascan.

It's not futile nor nonsense. I've used electric for my dinghies since
1999 with success and happiness. Total weight is little or no more
than an old 2-stroke and extra gas.

I have no objection to an outboard, but remember he's in a situation
where he has no place to store it except in the home or car. A smelly
and very dangerous thing to do.

Rick

Old 2-stroke (3.5 HP) = 30 pounds
2 gallons pre-mixed gas/oil = 16 pounds
Total weight = 46 pounds
runtime = With 2 gallons of fuel? Bwahahahahaha!
recharge time = 1 minute
Additional runtime available in minutes at any fuel dock

Group 24 Deep cycle battery = 45 pounds
SMALL electric trolling motor (.25 HP) = 20 pounds
Total weight = 65 pounds
runtime = Do the math. 35 MAX usable amp hours, motor draws 35 amps at
full speed.
recharge time = 12 hours. Battery must be brought to shore and
attached to a charger for 12 hours before it can be used again.

So, 46 pounds gets you 3.5 HP for effectively unlimited runtime, and
65 pounds gets you .25 HP for 2 or 3 hours of runtime at MUCH slower
speeds before you need to go ashore for 12 hours.