T-Pain Is On A Boat: [Electric Boats] Re: Re-Powering a Catalina 27

Tuesday, August 18, 2009

[Electric Boats] Re: Re-Powering a Catalina 27

Gary,
Welcome. I hope you find an electric solution that works for you. Both Keith and Eric offer great perspectives, each recommending the safety of long motoring times. If you can get by with 20 minutes instead of 20 miles (without a generator on board), you would have a light, inexpensive, simple, reliable but short duration auxiliary propulsion system. There is much available in 24 to 48 volt motors and controllers, both brushed (cheaper DC) and brushless (efficient AC). Higher voltages are great for higher efficiencies and much higher costs and weight and power. There are also smaller, lighter AGM batteries, or cheaper FLA, and I recommend each with its own smart charger. LiFePO4 batteries are at most half the weight and size, and at least twice the power and cost, but at least four times the longevity.
The ballpark of most battery-electric vehicles is one gallon of fuel (can go about as far as a similar vehicle with 1 gal). Would you be happy with one cup of fuel? Just slip and harbor tacking help?
Mark Stafford
Herreshoff 55 project (96VDC, 1,000 lbs golf batteries)
GreenMarineRePower.org

--- In electricboats@yahoogroups.com, "Eric" <ewdysar@...> wrote:
>
> Keep in mind that a single AGM 12v Group 31 battery that is rated at 100AH weighs 78 pounds. A bank of 4 will weigh 312 lbs and have a little over 3kwh usable capacity due to AGMs allowing for a deeper discharge. The eight batteries suggested below will weigh over 600 lbs....
> Eric
>
> --- In electricboats@yahoogroups.com, "aweekdaysailor" <aweekdaysailor@> wrote:
> >
> > Hi Gary,
> >
> >
> > There are several companies, some who monitor this list, who provide drop-in replacements for Atomics. Pricing varies from ~ $2500-$4500 excluding batteries. You can DIY with a kit for about $1500 but the mounting brackets, etc can be tricky.....
> Keith