Tony Kenny wrote:
("Paul E. Bennett") wrote in message
...
In article
"Tony Kenny" writes:
snip
So, a 12v 140 Amp-hour battery on a 4kW motor will last 0.336 hours?
Or have I made a tits-up of the calculations there? At half speed
that would give 1.344hours? Seems like I'll need an extension lead in
the water with me 
try looking for heavy-duty milk float or oil rig batts. Or the larger
yacht/boat batteries.
I used to work with someone who was going to build an electrically powered
canal boat. He was going to have a bank of oil rig batteries or the like,
and an electric motor mounted inboard. His plan was to cover the roof with
large sloar panels. He reckoned that for one days charging he could get one
days cruising. This means either(a) travel every other day, then charge for
a day or (b) travel at night and chage during the day.
Look at solar and wind power to keep your batteries topped up.
Simon