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Final dumb Magneto question for the weekend

Posted: Sun Mar 29, 2020 4:58 pm
by Marshall V. Daut
O.K. I'm convinced. I'll try to talk my friend into having his coil ring rewound professionally. Thanks to everyone for the leads and recommendations as to who should do this.
Looking ahead once I receive the NEWLY rewound coil ring, I intend to recharge the weak magnets before reassembling the engine. I have done this with three 12 volt car batteries long ago, but it was always a hassle rounding up three good batteries and all the necessary connecting cables. I'd prefer to do this with a professional grade battery charger available to me, namely a Solar 480 model. See the attached photos of the charger and its specifications along the top of the front face. Will this be sufficient to charge the magnets? I know that three 12 volt batteries equals the recommended 36 volts (even with my poor math skills and using the New Math, I can figure THAT out!). But will this battery charger supply the necessary amps to do the job? What is considered "enough" amps to recharge the magnets? Should I use the highest setting @ 12 volt boost? If not that one, which setting? I looked through past threads on this topic and never did find the definitive answer. Lots of dancing around in answers, but no Yes/No input. So, yea or nay on the battery charger?
'Sorry, but electrical things have always been a bugaboo for me.
Marshall[image][/image]

Re: Final dumb Magneto question for the weekend

Posted: Sun Mar 29, 2020 5:17 pm
by Marshall V. Daut
I should mention that the plan is to place the coil ring on top of the magneto when charging the magnets. I will not be charging the magnets individually.
M.

Re: Final dumb Magneto question for the weekend

Posted: Sun Mar 29, 2020 5:23 pm
by AndreFordT
Marshall,

I don't think 12Vdc is enough to recharge the magnets. I once did it, during a ride, with a 12V and 6V in serial 18Vdc. It worked and the car is still running on this recharged magnets.

I use two 12V and two 6V battery (that is all I have in stock) in serial they give me 36V.
What is important is that you put the North poles of the magnets on the South poles of the coil loop.
Make a good contact with the + connection of your battery loop and flash a few time with the - connection.
If your batteries are Ok and you did the recharge right you should need a pry bar to separate te coil loop from the magnets.

Good luck
Andre
Belgium
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Re: Final dumb Magneto question for the weekend

Posted: Sun Mar 29, 2020 5:53 pm
by Marshall V. Daut
Good stuff! Keep it coming. The main reason I asked about using a battery charger is because of these two VERY short videos:
https://www.youtube.com/watch?v=1gTv8JNz_Mo
https://www.youtube.com/watch?v=zzQJLGt ... e=youtu.be

It sure looks more efficient than hooking up a bunch of batteries. In the video the man says his charger puts out 300 amps. Will THAT be enough to do the job? He got the magnets in some places up to 100 Gauss. He says to shoot for 80+, but 70 didn't seem to bother him much. Without a Gauss meter (a VERY expensive toy!), how does one tell if that magic figure has been achieved? Is it necessary to know that? I will assume that after charging the magnets, if I have difficulty separating the coil ring form the magneto, the magnets must be sufficiently charged. Or???

Marshall

Re: Final dumb Magneto question for the weekend

Posted: Sun Mar 29, 2020 8:08 pm
by Tom D
Marshall, I have read lots of people with different methods of recharging the magnets. And many of them have posted that their various methods have been successful. So it might not really be that critical just how you do it. However, over the years I have gathered great respect for John Regan and his advice. He seems to be an advocate of being more careful then some, and not using too much power to recharge. Here is a post of his. Look down at about August 1:

http://www.mtfca.com/discus/messages/25 ... 1343922852

Tom

Re: Final dumb Magneto question for the weekend

Posted: Sun Mar 29, 2020 8:28 pm
by Philip
I use my dc welder It has to be a dc welder not a buzzbox. It works great.
Do a search and you will find instructions philip

Re: Final dumb Magneto question for the weekend

Posted: Sun Mar 29, 2020 8:52 pm
by Wayne Sheldon
I would like to hear from a couple of our BEST electrical engineers on this. I know a lot on the subject, but i also am well aware of what I do not know.
Personally, I would think several times, and hesitate at the idea of using a battery charger for this. My reason? I tried something similar a few times. And it didn't always work out too well for me. Somehow, over the years, I have acquired a few (4? 5? 6?) mediocre 6/12 V battery chargers. None of them are cheap "trickle" chargers, but none of those are really well built expensive units either (I do have a somewhat better charger in decent condition, but I haven't been willing to risk it).
I have often been short of batteries to abuse with such things. So I have several times used battery chargers to work the de-rusting (electrolysis) tank, or charge magnetos. When I needed the voltage charge a magneto, and had only one or two batteries available to use, I tried using the charger in series with the battery or two. I also tried using the battery charger for de-rusting (and I found it worked better on the 6V setting). Both efforts, several times worked fine. No problems. However, I managed a few times to "break" my charger. They would blow diodes inside, and one of them blew the amperage meter on the charger. I replaced the blown diodes, and had to note on two of them that the meter could not be trusted. I still have two of them that need to be fixed from my last failed effort.
If your better charger is well enough self-protected? It should be able to do the job just fine. But if it isn't well enough protected? It would be a much bigger loss than my few that most I got for free (and I still have my better one if I need to charge a battery).

Battery chargers aren't designed to power anything. A battery in decent condition in itself acts as a suppressor that acts to protect the charger. Small limited draw devices won't hurt a decent charger (current/amperage demands and limitations is the key). Powering something like an electrolysis tank could "over draw" from the charger, and if the charger doesn't have an adequate protection circuit?

Re: Final dumb Magneto question for the weekend

Posted: Mon Mar 30, 2020 2:40 pm
by fbergski
I experienced poor results using the field coil to recharge my magnets, instead I found a dedicated magnet charger through my club. Using a 12v lawn tractor battery I've recharged all of them individually then checking to see if they can lift a cast iron piston, all passed.

Re: Final dumb Magneto question for the weekend

Posted: Mon Mar 30, 2020 2:42 pm
by tdump
if you live in a nieghbor hood that allows golf carts, a 36 volt golf cart is ideal for a power supply.