Pelton wheel gensets for boats, need EV Info.

Thanks, I am planning on a Pelton wheel geared to a one wire GMC or similar 100 amp. alternator in a case mounted to my electric boat transom. I would like to partially replace the 48 volt battery packs use, to extend my cruising range. Total replacement is not a goal, but a 12 or maybe 24v alternator (48 volt ones plenty bucks ) should be able to be stepped to get 48 volts at lower amps. I hope so anyhow ??

What I have is a 48 volt motor, it's best power point is 73.68 amps draw, at 3,800 rpm. the outboard lower unit will reduce the RPM by half. In exchange we get a really big prop with our torque similar to a Isuzu car, but at a lower RPM limit. l will use a high amp hour 48 volt battery setup that is being created now, next time maybe the 72 v. unit. the motor is in the shop and getting ready for water jacket pump, and wiring stuff. I just started on this as a demo. boat for the EV power systems that I show and sell, so it needs to be right, we convert blown up outboards with this set up .

Back to the pelton wheel.

1 -- Can I get enough power from a boat at say 4 to 5 mph, which is a decent lake cruise speed to do any good at recharging a battery pack, once it is stepped to 48 volts ?? Water wheel size ??

2 -- I was just thinking that a common 12 in. pelton, geared maybe 4 to one might do that, but will that wheel size do I need , and can I do a bigger wheel to little wheel simple bicycle drive increase ??

3 -- Can I get a charging rate of (guessing) part throttle, around 10 amps (or more) from a wheel ?? That would help offset the drain as follows. Battery pack is combo series/parallel wired at 48 volt - batteries figure 175 amp hours, but using close to half as possible maybe 100 amps max. that would give a cruise time of about 2 to three hours min., depends on wind, waves etc.


SUMMARY -- Can I get my water time extended by a Pelton wheel, is it worth pursuing for extra range. What size Pelton do I need to make it work?? I see "falling water" figures but that doesn't make lake cruising easier for me to guess at. Sheesh, all I need is to put it in the water, but maybe I can use less amps with a wheel ??


Thanks, Cal

I am not clear on what you're proposing here. However, it seems that you are hoping to tap the kinetic energy of a boat to charge a battery system. Are you considering some kind of regenerative braking system? This doesn't seem practical where frequent stops and starts are not seen. Are you thinking this can be used while maintaining cruising speed to reduce battery discharge rate? If so, then note that if all the relative motion between your boat and the water is due to the energy derived from your propulsion system, then using this energy to recharge the battery cannot provide a net gain. In fact, the losses involved would only deplete the battery system faster, all else equal, as the drive motor would have to increase output to compensate for the added resistance presented by the wheel.

Yes, using both the forward speed, adding whatever wind that pushes the boat opposite the direction of flow, and passible wave action that in some positions will also cause rotation of the water wheel. No, there are no brakes on boats in general, reverse is not used at much over idle speed, so forward or coasting is what we get to use.

I'm not so sure about the force of movement taking away potential power like just air -- water is what ? 200 or more % solid than air, so it should have more force. I'm hoping that at a cruise speed the water force might have enough force to make the wheel spin under the light weight bicycle drive chain load.

I see what you are saying, and I would agree in air forces, but what I am trying to figure is what diameter size pelton wheel that will use water at say 5 mph to generate what i need. I see some at around 12 inches, and wonder if that is big enough, or if there is a different "paddle wheel" or bucket set up that will overcome the generator drag enough to make some power return. Some place must make a drive that will turn a generator with 5 mph pressure, and turn a wheel to return some amps. I was hoping for a source for that as a simple setup to test, or i will just guess, build and try it out.

Does that clarify things ?? ----------- Thanks, cal

Okie Dokie !! It looks like the information is listed on --- www.pumpfundamentals.com/micro-hydro --- they list several wheel types. The only way to learn is to try, and I need a different voltage than they show, so I will build it and see.

Thanks for the comments, always welcome to chat a bit ---- cal

Hello cal,

If you have a boat, it has a motor, it has a shaft, then the last thing you wont is any form of water turbine to place drag on the boat.

Spin an alternator from the motor shaft.