Battery power

[CalGoldDredger]

Aww, ain't that cute.

[au_miner]

If you go on ebay and look under dredge there is an electric dredge listed, but it is in austraila

[Hoser John]

And what are you going to be when ya grow lil'HBr??John-- a fella came into my biz with a tiny tinker toy dredge just about that size and gave it to us and we put it in our wet/dry processing area in the store and folks got a laugh outta it for quite a few years. Fun stuff-John

[JasonG]

Look at LiPo batteries, they are kinda all or nothing, they give you full juice until they are dead and then nothing so there is no decreasing power curve, I think they are just about the highest energy density battery you can buy right now too (read: lighter+smaller for equivalent energy). But, any lithium battery can be reactive (explosive) to water so probably not the safest thing to use for a dredge, although they are sealed and you could seal them again for more safety.

Electric motors are much higher torque than combustion type engines and similar or higher rpm, so you'd probably be good with a 1hp electric motor mated onto a standard centrifugal pump from keene or proline or wherever to get the required amount of pressure, might even be able to get away with using a 3/4 hp motor. You can buy them + speed controller for about $50-60 at electric bike stores, I got a 3/4hp one that is powerful enough to push me uphill at about 15mph and 25-30mph on the flats, I weigh almost 200lbs and the motor is pretty light and compact compared to a 2.5hp gasoline engine.

Anyways, it seems like a couple people a year talk about building an electric dredge but nothing much ever comes of it, I guess there is some limiting factor involved that makes them uneconomic.

[urbanminer]

I've been doing a little research and have a few questions. DC motor or AC motor with inverter? I'm also looking at submersible waterfall pumps. One looks real good with 11/2 inch discharge and 50 foot head. I think that would produce enough pressure for a 3", maybe 4"? Battery longevity seems to be the biggest hurdle. Without going bankrupt, about the best running times would be in the 1 to 11/2 hour range and run a solar panel to recharge between runs. I'm throwing this against the wall and we'll see what sticks.

Marc

[Hoser John]

PSI and GPM are the ruling factors-all else fails miserably in the requirements to run a dredge--John

[El Dorado]

non-motorized means no motors and an electric pump is powered by a motor........ you would do much better with a gravity dredge........no motors, no batteries, no pumps. But it is still a fish killer in CA.