Easy/cheap generator for charging batteries?

DUDE, thats almost $70 worth of stuff! A very big thank you to you, sir! That charger should eliminate the need for a regulator. I may still need a rectifier though, but I think I still have one from my old lighting setup. The charger box will actually make the whole thing very easy to install. Just need a bit of solder and I'll have it done in an afternoon. I think Tuesday (my next day off) I should be able to get the whole thing set up. Thank you very much again, sir!
 
I got the generator and the mini-charger today. I sent a message to mightywonderful, the seller of the mini charger, and according to them the mini charger has a rectifier, regulator and a fuse. So that means I should be able to just install the generator, the charger and hook all the wires up correctly and be good to go. Thanks again, Harold!
 
Harold, do you know what the green wire on the mini-charger is for? Both red wires are positive, and both black wires are negative, just don't know what the green wire is for. Also, the fuse is blown. Perhaps that is why it did not work for you? I'm not mad about it or anything. Replacing a fuse is cheaper than having to buy all these parts new.
 
I had very little to no luck with the minigen even after adding the high output secondary magnetto coil. But then that was with a two stoke and some incandescent bulbs in the mix. If it doesn't work for you or your application I'd say salvage what you can and pitch the rest. My understanding is the green wire goes to a light switch. The eBay link has the connection details. Maybe the Mightywonderful sellers will stand behind it if there is an issue. I forgot about the fuse. Bummer because I carried spares. Don't get too excited and you won't be too disappointed if it doesn't work out. None the less, good luck!
 
I'm going to buy some different amperage fuses. If one blows, I will go to a higher amperage one until they stop blowing. I think maybe the reason the mini charger didn't work out for you is because of the way you had all the wiring connected. There was a white wire soldered to the battery positive terminal, and the green wire had also been spliced into the battery positive. I also noticed that you had a ground wire and another wire connected to the same connector. That may have caused some sort of short. I cleaned everything up. The green wire has been shortened and capped off with some shrink tubing pinched shut over the end of it since I don't plan to use it. The white wire was removed. The connectors have all been removed, except for the one on the end of the battery positive wire. The blown fuse has also been removed. I will go to either advance auto or walmart tomorrow and get replacements. Also, without the hardware for the generator, the only place I'm able to mount it securely is to my front fork to be driven by the front tire. Since I have front suspension, I'll need to figure out a way to keep enough slack on the wire coming from the generator to the charger without it getting snagged, as I have exposed springs on motorcycle triple trees.
 
I was able to find a way to mount the generator over the rear tire, where I originally wanted it. I didn't want it on the tire sidewall, due to my wheel not being 100% true I was concerned about the generator roller not making contact the whole way around the wheel. So I took two metal pipe clamps and flattened them, then placed them so the clamped around my frame right above where you would normally mount a fender. I placed the generator so that the roller sits directly on top of the tire, ensuring contact 100% of the time. I also mounted the mini charger on my luggage rack. Tests with my multimeter confirm AC voltage from the generator as well as DC voltage from the mini charger. It works! Now the only things left to do are get some fuses and mount my power distribution terminal and connect everything to it. I'm thinking with the power distribution, I should really only need one battery. I've been running two batteries, due to the fact that I've got two lights and needed to be able to disconnect the batteries for wall charging. Now I shouldn't need both batteries anymore.
 
I was able to mount the power distributor and use only one battery. All the wiring is connected, the only thing left to do is replace the fuse. I activated both my lights after connecting them to the power disributor, everything works properly. There is an auto parts store near the bank where my wife and I are going to set up a new account today, so no need to make a special trip on my bike. I only got a few hours sleep, and I'm too tired to drive anywhere. I'm very excited to get this fuse. I can't believe I got this setup working in just a few hours with very little sleep, lol. It was really a lot easier than I thought it would be.
 
I just went back out and cleaned things up a bit. Added a new connector to the wire coming from my brake light switch to the battery. Now all that's left to do is go get a new fuse and I'm good to go. Since the charger is only 12v and my batteries tend to read about 16v after a good wall charge, I'll be checking my battery with a multimeter a few times after riding to make sure the system is actually charging the battery and not draining it, as my wife's brother-in-law seems to think it will. I think it will be fine, but we will see.
 
After doing some reading on nicad batteries (the type I currently use), it seems that in order to reach a full charge, the charge voltage must be more than the battery voltage. I am fairly certain this will affect my system, and I may need to switch to an sla battery. sla batteries can charge at voltages closer to the capacity of the battery, therefore a 12v battery will charge at 12v. I will still continue to test my battery every day and check my lights to see how they work. If the system can charge efficiently, I'll stay with the nicad battery. If not, I'll have to switch to sla.
 
So I got a pack of 4amp fuses at advance auto. I installed the fuse and went to test the voltage. I did this by starting the bike on the center kickstand and giving it gas while touching my leads to my bike. The mini-charger is supposed to have a voltage regulator built in, but the voltage was all over the place. Is this normal? Or did I test it incorrectly? I tested it by touching the positive lead of my multimeter to my power distributor, a positive terminal with 5 connections. The voltage spiked way over 12v. Also, when the bike is on the stand, there is no load on the engine or wheels. The generator gave off a few sparks and got a bit warm to the touch. Not hot, just warm. Is this normal? Maybe it won't get warm when there is a load on the rear wheel? Maybe the voltage in the charging unit wont spike either with a normal load on it? Any ideas anyone?
 
Sparks!? Hopefully that stopped. What was sparking? I would assume the generator voltage would fluctuate a bit since the drive wheel is neither perfectly round or perfectly concentric to the shaft. The rear wheel is not likely to be truely round either. That would make the generator tend to speed up and slow down making the voltage vary. Not sure about spikes.

The minigen had some issues which is why I had a couple of the leads tied together that are normally not. The guy at Mightywonderful had said they should be connected internally anyway so he suggested soldering them together. Perhaps reconnecting them will make a difference. It has been several months since I messed with that and don't recall exactly the problem it was supposed to correct. I would suggest contacting Mr. Mighty again.
 
After thinking about it, the voltage is probably correct. My battery when fully charged reads 16V+. And I know that you can't charge and discharge a battery simultaneously (although you can charge one cell and discharge another, but to my understanding that only happens with a balanced charger, which this obviously is not). So I didn't think the battery voltage and charger voltage would read at the same time. I figured if the charger is producing current, then my meter should only read 12v. But it read 28v+ with the generator running, which would be the voltage from the battery and the voltage from the charger combined. But I am going to need a 12v sealed battery. Testing with the multimeter confirms that because the voltage produced by the charger is less than the capacity of the battery, it is actually draining the battery instead of charging it. I am going to look on ebay and amazon and see if I can find a sealed battery that's within my budget right now. Hopefully I will find something reasonable.
 
I just ordered a 12v 1.2Ah SLA battery on ebay for $6, plus $5.95 priority shipping. If they ship it tomorrow, should be here by Saturday. I think in the meantime, I'll disconnect the charger from the generator and insulate the wire with some electrical tape. With it disconnected from the charger, the battery I have now should stay charged until my other battery arrives.
 
To follow up on what the vendor told you about connecting the leads internally, he is incorrect. A circuit basically consists of four connections. A positive and negative input, and a positive and negative output. Obviously the negatives can both go to the same ground, but the positives can not be connected to one another. As far as the green wire, if it just goes to a switch, I don't see how connecting it to either positive would have any effect at all. If anything, its just causing the current to go in a useless loop between the two wires. I'm not criticizing you Harold. You just went by what the vendor said, and that's understandable. I don't know why you were having bad luck with the charger. I do know that all I did was remove the extra wires and make sure everything was connected to the right places, and replace the fuse. The charger is working fine for me, so obviously there was nothing wrong with it in the first place. The generator also works fine. The only reason I am saying this is because the best way to learn about electronics is to research it. I had a member whose name I won't mention give me some bad advice (possibly on purpose) about batteries and charging circuits. I wont get into all the details, but by the end of it I decided to do my own research from then on. When it comes to electronics, you want to make sure you are doing things right. Doing things wrong can only result two ways. One, you lose money on something that doesn't work for you, or two, you fry something, and that can cost you more money as well as personal injury. I'm very appreciative that you gave me these parts to use, but I do feel bad that they didn't work for you. When it comes to people giving me things, I don't have a "your loss is my gain" attitude. So I hope whatever lighting system your building on your new bike works out for you.
 
I couldn't be happier in that you are getting good use from parts that were otherwise scattered about my garage. I am confident the system would not have been up to the task on my bike. There are two 450lm LEDs in the tail light and a 1440lm LED in the headlight. The headlight LED requires a buck/boost. That's "so far". I'm considering running lights or turn signals and that would ad four 450lm LEDs minimum. I haven't decided on the front fender running light yet.

Perhaps running the minigen with a bottle generator is a better use for that regulator. I had it on my two stroke wired into the magnetto coil. The issue for me was that it is a black box. Everything is potted so there is no tracing a circuit. Had it not been at the end of the riding season, and that I needed to completely rewire the bike for a couple of LED industry shows I might have stuck with it. As it was I chose not to.

My loss, your gain? Nope. I could have dumped them on eBay for a few dollars but instead chose to send them to you. I hope in the long run it works great for you so your gain. If so I hope others with the same or similar parts can make lighting systems for their bikes and we all gain. I also hope a small gesture creates some good will and therefore I certainly lost nothing!
 
I'm glad that you feel that way then. You're right, this charger probably isn't capable of running high wattage bulbs. I have no idea the actual lumen of my bulbs, but the headlight is 5w and the brake light is 3.6w. I chose them specifically for their low wattage. The brake light is not super bright, but bright enough. The headlight is extremely bright. But again, they are very low draw. With a charging circuit, the battery only runs the lights when the power supply is not producing (in case that doesnt make sense, when the bike is moving the generator is powering the lights. Only when the bike stops do the batteries take over). So high wattage bulbs might overwhelm the charger, regardless of what's driving it. Like I said, I'm glad that you gave me this stuff, and its working great for me. Just to clarify, what I meant when I said I dont have a "your loss is my gain" attitude was that I'm not one of those type of people who greedily takes anything that someone else is willing to get rid of without being considerate of the reasons why they don't want or can't use it. That's why I said that I'm glad you gave me these parts, but I do feel bad that they didn't work for you, and I hope that your new lighting and electrical system works out much better for you. I just didn't want you to think I was saying something negative.
 
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