15 HP electric outboard production unit

[angus63]

Came across this

www.whisper-electric.com

Wanna plane off with your trolling motor?

 

[tashasdaddy]

Re: 15 HP electric outboard production unit

did not see any pricing. but interesting.

 

[JB]

Re: 15 HP electric outboard production unit

Hmmmmmm. 15HP is about 11.2KW. Even at 120volts (Ten 12V batteries) it would draw nearly 100 Amps and suck those ten 100AH batteries dead in an hour or less.

Trying to run it on 12V would be damned scary. 1000 Amps is more than most big rig starters.

That assumes that there are no heat losses, and heat losses at those rates of current are guaranteed.

 

[Silvertip]

Re: 15 HP electric outboard production unit

That motor runs on 24 to 72 volts. Maximum current draw is 75 Amps at about 250# of thrust. So with six big (group 27 or 30) batteries you have the equivalent weight of a mid range outboard. About the only use I see for what is likely a very expensive motor is on an electric only lake and on a pontoon.

 

[JB]

Re: 15 HP electric outboard production unit

Well 75 amps at 72 volts is only a little more than 7HP, assuming no heat losses.

Which claim is correct? They can't both be correct.

 

[Silvertip]

Re: 15 HP electric outboard production unit

Those are their numbers, not mine. The web site has a current draw/thrust chart.

 

[Saskatoon2005]

Re: 15 HP electric outboard production unit

The price of this is $4,495.00US. That seems like a ton of cash to spend on this motor...when you can get a used 15HP outboard for $300.00, or even a new one for $2200.00 new.

 

[kandil]

Re: 15 HP electric outboard production unit

That is nice kind of pricey http://www.martiniboats.com/whisperelectrico.html
I wonder if the prop guard on it a good thing or a bad one?

 

[angus63]

Re: 15 HP electric outboard production unit

Yup, had all the power out ,weight, power source, price, consumption considerations you guys mentioned. I think their claims of equiv. to 15hp must include weight:thrust considerations. Anyway, I did not choose this motor for my hydrogen fuel cell boat, but went with two smaller Minn*Kota's to achieve hull speed with lowest power draw. Cost made my eyes spin too!!!​

 

[TerryMSU]

Re: 15 HP electric outboard production unit

Here is my guess on the rating...

The thrust of their "15HP" is claimed to be equivalent to that of a 15hp outboard. If you read the brochure, it claims that "thrust exceeds that of a 9.0HP gasoline motor at 60 volts". Exactly what the test conditions on either motor were was left unstated (prop, rpm, etc.) Still, I think they are playing games with specifications. If you compare it to a badly set-up 15HP outboard, maybe it will match the tested thrust values. This is a common marketing ploy. 15 HP at 72 volts requires 155 amps. Basic high school physics.

On the other hand, if I took that prop setup and put it on a decent low horsepower gas motor, what would it do then? That shroud and prop combination could really bump up the efficiency of the motor (at least until it gets caught up in the weeds).

TerryMSU

 

[angus63]

Re: 15 HP electric outboard production unit

If the power out exceeds the power in, even if 100% efficient with no losses, it's called marketing. Let the buyer beware.....

 

[Wee Hooker]

Re: 15 HP electric outboard production unit

Clearly a "green age" marketing product to suck in those with a green mind who have more $ than technical/practical knowledge. Any consumer claims of "it's not powerfull enough" are likely to be met by teh factory with accusations of "you didn't supply it enough electricity."
No doubt they could achieve a good big electric motor but battery size /capacity continues to be the long pole in the tent to overcome. (Our own Navy spends Millions /year trying to improve battery technology and has been only marginally sucessful.)

 

[pvanv]

Re: 15 HP electric outboard production unit

Plus, consider the additional costs: weight, monetary and environmental, of having all those deep-cycle batteries to buy and maintain... and dispose of after a few years.