T-Pain Is On A Boat: Re: [Electric Boats] Re: Battery charging time

Saturday, July 10, 2010

Re: [Electric Boats] Re: Battery charging time

Thanks Kirk

I am just trying to use the honda 1000 as an example compaired to a 10 kw.

I want to go with an electric drive but my sailboat weighing in 20,000 lbs would suck up a battery pretty darn quick. I am getting the idea that I may be able to run about 4 knts using only 4kw of available power so a small generator would give me that plus a little bigger to charge batteries while running.

Aaron

--- On Sat, 7/10/10, Kirk McLoren <kirkmcloren@yahoo.com> wrote:

From: Kirk McLoren <kirkmcloren@yahoo.com>
Subject: Re: [Electric Boats] Re: Battery charging time
To: electricboats@yahoogroups.com
Date: Saturday, July 10, 2010, 4:18 PM

I dont know if the new Honda works better than the one Home power tested a few years back but their review wasnt as well as one may like.

A resistive load takes current proportional to the voltage but a battery is a no load until the output voltage equals the battery voltage plus rectifier drop.

They intimated the units reulator was a bit upset at this and only achieved about 2/3 of rated output.

Might want to read about it if you can.

Kirk

From: hardy71uk <p0054107@brookes. ac.uk>
To: electricboats@ yahoogroups. com
Sent: Sat, July 10, 2010 5:28:23 PM
Subject: [Electric Boats] Re: Battery charging time

Well I estimate on the back of an evelope as follows-> takes about 1.2kw hours per battery . so 4.8kwh total . if you had a 100% efficient charger that would take about 6 hours for an average input of 800watts. Say 8 to 10 hours for a reasonably efficient real charger. I'm guessing that the honda 1000 could probly provide 800watts continuous.
Efficiency wise I think we are talking around 6.5KWH input for about 4KWH to the motor.

Chris S

--- In electricboats@ yahoogroups. com, Aaron Williams <akenai@...> wrote:
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> If I had a 48 volt system with 4 12 volt 100 amp hour batteries how fast could they be charged. If I had a 10 kw generator how much would be wasted.
> What I am wondering is if one of the Honda 1000 gen sets is more than adequate?
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> --- On Fri, 7/9/10, hardy71uk <p0054107@...> wrote:
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> From: hardy71uk <p0054107@...>
> Subject: [Electric Boats] Re: Anyone have experience with 144 volt motor systems?
> To: electricboats@ yahoogroups. com
> Date: Friday, July 9, 2010, 2:38 PM
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> Good points . but usually the greatest efficiency loss comes from using a gen to charge batteries . Best practice might be to charge from shore power and run the motor some of the time from the generator to conserve the battery power. DC motors can be run from an ac supply via a simple rectifier.
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