# Homemade Generator Problem



## motdaugrnds (Jul 3, 2002)

My son is making what he calls a "PEG" generator. "Portable, Electric, Gasless" Generator. It's basically a battery and inverter in a box he made from some scrap OSB board with a solar panel and 2 small wind turbine generators fastened to the outside of the box. Keeping it in full sun he figures the solar panel will keep the battery charged except on cloudy days the wind will run the 2 small turbines so they will keep battery charged. Is light enough to carry around in one hand.

Flip the switch to turn on the inverter and he can run a drill, electric chainsaw, etc. anywhere on our property (little over 6 acres) without the need for mass amounts of extension cords to reach from a power outlet to wherever he is working.

He got everything made and hooked the wires from the solar panel to the battery before taking a break for a few hours. Later came back intending to hook up the wiring from the 2 turbines and noticed the solar panel was hot to the touch (battery and inverter inside the box were still cool to touch). Disconnected to solar panel and it slowly cooled down. Tried to hook up the turbines and found out the battery was making them turn so realized the solar panel must have been draining the battery as well, is why it got hot.

Anyway that's his problem. He needs something that will prevent the electricity from going from the battery to the solar panel and turbines (only wants the power to come from the panel/turbines to keep the battery charged, not having them drain the battery when connected). Also doesn't want to "overcharge" the battery.

Does anyone have any suggestions what he is missing here?

Thanks


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## PD-Riverman (May 24, 2007)

Its called a blocking diode. Only lets power go one way. They come in different amperage/sizes. Needs to use one some bigger than the solar panel is rated.






motdaugrnds said:


> My son is making what he calls a "PEG" generator. "Portable, Electric, Gasless" Generator. It's basically a battery and inverter in a box he made from some scrap OSB board with a solar panel and 2 small wind turbine generators fastened to the outside of the box. Keeping it in full sun he figures the solar panel will keep the battery charged except on cloudy days the wind will run the 2 small turbines so they will keep battery charged. Is light enough to carry around in one hand.
> 
> Flip the switch to turn on the inverter and he can run a drill, electric chainsaw, etc. anywhere on our property (little over 6 acres) without the need for mass amounts of extension cords to reach from a power outlet to wherever he is working.
> 
> ...


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## Jim-mi (May 15, 2002)

Sounds like he got the polarity backasswards ..............

He's in for a rude awakening about those "wind turbine" toys.......


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## Ed Norman (Jun 8, 2002)

Describe these little turbines please. I had thoughts of a small wind turbine that I could stick in a rod holder on the boat, and recharge the battery to and from the lake. It's a few hundred miles.


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## sandc (Apr 26, 2010)

Ed Norman said:


> Describe these little turbines please. I had thoughts of a small wind turbine that I could stick in a rod holder on the boat, and recharge the battery to and from the lake. It's a few hundred miles.


My buddy pulled the axle out from under his boat and installed the rear axle from a toyota truck. He is a circle track racer and uses a bracket that mounts his alternator to the rear axle to take the drag off of the motor. He fabbed up a similar bracket onto the toyota rear end and uses a regular gm 2 wire alternator to charge the 6 batteries in his boat. He has that many because he bowfishes at night. I think his total cost was around $200.


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## mightybooboo (Feb 10, 2004)

Ed,I think just getting a battery isolator and using cars alternator would be a far better solution cost and performance wise,no need to reinvent the wheel IMO.


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## farminghandyman (Mar 4, 2005)

IS he using a charge controller?


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## Ed Norman (Jun 8, 2002)

Well I have a 30V ? DC motor from a treadmill that I thought I could use with a regulator. So it would be more of an experiment than an invention. 

The axle trick is pretty inventive. I could see bolting a pulley onto the lug bolts and mounting an alternator on the fender, with flapping wires in the wind. Might as well bolt an AC compressor on the other fender to make bubbles for the livewell.


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## 12vman (Feb 17, 2004)

motdaugrnds..
The "PEG" needs two things. Isolation between the three charging units by using blocking diodes and a way to regulate the charge to the battery.

A charge controller will isolate the battery from everything. It has blocking diodes built in. If all 3 charging units are combined to one charge controller, they need a "check valve" or a blocking diode to avoid them from fighting each other. (Power from one unit going to another)

Example.. Sunny day with no/low wind..
The solar panel is making power but the wind gennys ain't doing much. Without a "check valve" between the panel and the wind gennys will cause the gennys to become a load and nothing will go to the charge controller. Each charge unit needs a way to avoid becoming a load to the other. Even if you have wind and no sun, the panel will become a load to the gennys. (As you seen by the panel heating up from the battery)

Hope this helps..


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## motdaugrnds (Jul 3, 2002)

Hi 12vman, this is David motdaugrnds' son.

I have installed a diode to the POS battery port and this seems to have corrected my problem.

Here's my set-up (as best as I can describe it):

Inverter running off battery (both inside the box)
Outside the box: Solar panel fastened to the top of the box (which is also a hinged lid for easy access inside the box) with 2 small wind turbines on either side of box
Connections inside the box are:
All 3 NEG leads from solar panel and both turbines connected to NEG port on battery
All 3 POS leads from solar panel and both turbines connected to POS end of diode
NEG end of diode connected to POS port on battery

So far this seems to be working. Is dark outside ATM so can't test if the sunshine on panel will make my turbines run but I seem to be reading that this is what you are saying will happen. Which means only part of the power generated by the panel will be reaching the battery (or vise versa on a cloudy/windy day the turbines will be sending some of the power to the solar panel).....

It sounds like you are suggesting installing 3 more diodes (one on each of the POS leads from panel and turbines) BEFORE connecting those 3 wires together and then to the battery (via the diode I put in from the POS port on battery).

Quick question: If I put those 3 diodes in so none of the power from any one of the 3 "chargers" will go to the other 2 chargers, why do I still need that 1st diode I put in from the POS port on the battery?


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## Roadking (Oct 8, 2009)

Had my own "revelation" yesterday...had two little panels, 12v, 1.5 watt battery cahrgers and wanted to tie in parralel...white stripe to white stripe, right? WRONG! Same manufacturer, same panel, but wires were reversed...white to black and black to white. Took about 10 minutes to figure out why it wasn't working...10 minutes to actually believe a mass produced product could be so botched up.
Working now, and charging my little portable power pack...
Matt


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## 12vman (Feb 17, 2004)

David..

One diode in the Pos. lead from each unit connected to your battery. The extra one at the battery isn't necessary. All commons (Neg.) connected together.

I'm not clear on the type of diode(s) you are using. If they have a band on one end, the band should be away from the charge unit(s) towards the battery.


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