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  Topic Review (Newest First)
11-14-2008 09:24 PM
johnnyboats thanks for the encouragement, yeah any kind of long range has to have a hybrid system. ive found two generators that produce 100 amps at 48v, one is at, the other is at, i recomend checking the later site out if your curious about electric drives, this system is different but i think has the most pros for any system. ive still got a few months till my boat even leaves the dirt, so plenty of time for more research!!
11-14-2008 05:37 PM
tomaz_423 Johnnyboats,
It is nice to read you are planing to use generator.
I was afraid you would hope to motor based on solar alone.
I am interested to hear the progress. Please keep us posted.
11-14-2008 05:00 PM
waltsn Good for you for trying.. Im wondering where you will find the 48 volt DC generator? Most of the small gas gensets you can buy (like the Honda's) put out all the higher power at 110 VAC only. Some have 12 volt outlets but its usually low power.
11-14-2008 03:53 PM
chucklesR Makes sense Johnnyboats, and seriously if it's a good plan for you then it's a good plan.
11-14-2008 03:06 PM
johnnyboats the electric drive system i would plan on using uses 40-60 amps cruising, about 150 at full throttle. i plan on having a generator producing 100 amps @ 48V, enough to keep up with any decent cruising speed, that would burn 1/5th gallon an hour, i would only run just electric for short periods, like entering harbors or docking, keeping the battery bank from draining any lower than 40% drained, greatly improving their lifspan.
11-14-2008 02:16 PM
chucklesR I don't know SD, I tend to take them on faith when they say that an electric motor has full torque at 1 RPM, and it's torque that moves the propeller not HP and because of that the boat only needs 1/2 to 1/3 the horsepower when compared to a diesel.

That said, the chart at the link shows 65 amp's (3120 watts) or 4.1 hp pushing the Islander 28 test boat (7000 pound displacement) at 5kts. With 220ah of batteries on board..make that 8000 pound displacement.
Maybe they have something there, maybe not. I don't have an Islander 28 to test with a 4hp outboard.

Of course, real world independent testing has proven otherwise.

We'll purposely skip the fact that they say 3 hours of use to take the battery to 80% drained because no good skipper would KILL his batteries that way.

dang it, I was going to stay positive..
11-14-2008 01:56 PM
sailingdog Chuckles-

Everyone knows that you can always trust a manufacturer's claims on their product completely. They'd never exaggerate or lie... would they???
11-14-2008 01:23 PM
chucklesR Max current on the 48v Solidnav is 150 amp, at that rate there would be on one hour total run time at full throttle before cycling (damaging) the proposed battery bank.

As I said in my post, I was trying to be positive

SolidNav :: The first alternative for everyone

of course the controller is rated at 4kw, so the max you can get out of it is somewhere around 5.3hp, disregard the link's stated 24hp equivalent - that would be at 150amp x 48v, 7200 amp controller needed.

Gosh, reckon they are fudging the numbers a tad?
11-14-2008 12:42 PM
waltsn Also worth mentioning... 30 amps at 48 volts is 1440 watts - a little less than 2 hp. Works OK on a 16 foot boat but may not get you out of trouble on something even slightly larger.
11-14-2008 12:20 PM
chucklesR 10 ah a day would be 15 days to fully recharge from a 50% drain with no other source of charge (mooring or no generator).

Powering a (48v) 30amp motor with 150ah of usable battery gives you 5 hours of run time, and if you are day sailing you'd need roughly a hour or less to just get out and sail (location dependent of course).

That 30ah for a day sail would be replaced in 3 days. Doing it twice on a weekend cruise plus minus overnight drain for house circuits (I run 40ah on average, but that's at 12v, you can call it an additional 10ah equivalent) and you'll be pretty much good to go week after week, if everyday is sunny enough to get you 10ah, 100% efficiency etc.

If the motor takes more than 30ah, adjust your throttle, run time etc.. and you'll be fine. Make sure you don't go short on system monitoring (meters).
Note normally I'm as anti-electric motor as it gets, for me this is a very positive post
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