Battery charge from magnetio?

[DCwom 78]

So I've got a Raider 12 which I believe was converted to a points ignition system at some point, I'm not 100% sure. In any case the battery doesn't charge, because, well, there isn't any charging system, the battery has to be connected to a wall charger after use to keep the battery up. There appears to be a couple of wires (cut) coming from the engine cover, I assume they are from a magneto, they go no where. The engine looks to have a starter only, not a generator/starter combo, so I'm wondering what might the charging system look like, can I put a rectifier & voltage regulator on these cut leads from the engine? And if I can, how can I test these wires to see if I'm getting good power, I'm thinking I'll need an oscilloscope.

[wallfish 17,023]

The charging system and the starting system or ignition system are completely different circuits

For charging there a system of coils called the stator. Under the flywheel.

What you want to check on those cut wires is for AC voltage. You will need a simple multi-meter to measure AC and DC voltage.

If those cut wires are putting out 30 ish AC volts then the stator and charging system will work with the addition of a rectifie/regulator. A rectifier will change that AC voltage to DC voltage which is what the battery is. Then you can use the multi-meter to measure the 12v DC out of the rectifier/regulator

First step is to test those wires for AC voltage.

[Handy Don 12,282]

If you can get the info (and a picture) off the engine spec plate, we can give you some more specific info. Also pictures of the wires on the engine!

 

Magneto and battery/coil engines can both use points (or some form of sensor/spark trigger) to control the spark timing.

 

Stators/magnet setups for generating electrical power from the spinning flywheel are common on both kinds of engines, too. Like @wallfish, I sense some problem with the stator(s) led the PO to give up on having the engine charge the battery. If you have working stator(s), then yes a rectifier or a voltage regulator (you don’t need both) could put you back in the battery charging business and maybe even give you enough extra juice for some LED lighting.  

 

Check those stators! 😄 Look for AC voltage between the two wires and between each wire and ground. Let us know what you find.

Edited November 6, 2023 by Handy Don

[wallfish 17,023]

4 minutes ago, Handy Don said:

(you don’t need both)

Rectifier --changes voltage from AC to DC.

Regulator "regulates" the DC voltage output so it doesn't over charge the battery.

Yes. you need both unless it's a low charging system. But most "regulators" designed for these engines are in fact rectifiers too all in the same component

[Handy Don 12,282]

12 hours ago, wallfish said:

Yes. you need both unless it's a low charging system. But most "regulators" designed for these engines are in fact rectifiers too all in the same component

Yep. Was trying to keep it simple until it’s clear what engine and charging system is there! If you buy a regulator, you don’t also buy a rectifier, right ?!

[DCwom 78]

Ok, now that I've got daylight I took a picture and measured the voltage on the two wires coming from the engine. Its about 16.5 VAC on my Fluke multi-meter at a medium idle. I'm not sure is that's normal, low, or high, but its what I measure.

 

Here is a pic of the wires from the engine.

Edited November 11, 2023 by DCwom

[pfrederi 17,743]

If you have a 10 amp system which was commonly on Chargers (but who knows what has been changes...what is spec # of you r engine

 

 

[Handy Don 12,282]

53 minutes ago, DCwom said:

measured the voltage on the two wires coming from the engine. Its about 16.5 VAC

If this is the voltage between the two wires, then you probably have the 10amp stator (alternator) and it appears functional. Hooray!

Note that the voltage should vary along with engine RPM, dropping to below 12 VAC at idle (1,000 RPM)

 

A couple other quick checks to confirm:

- the resistance of both wires (separately) to ground -- should be infinite on both (no or measureable resistance could indicate a short circuit)

- the resistance across the two wires -- should be very small but finite (<5 ohms -- the resistance of the coil of wire wound around the iron cores of the stator)

 

It the above check out, then by adding a voltage regulator, you can again get on-tractor charging for your battery!

[DCwom 78]

2 hours ago, Handy Don said:

If this is the voltage between the two wires, then you probably have the 10amp stator (alternator) and it appears functional. Hooray!

Note that the voltage should vary along with engine RPM, dropping to below 12 VAC at idle (1,000 RPM)

 

A couple other quick checks to confirm:

- the resistance of both wires (separately) to ground -- should be infinite on both (no or measureable resistance could indicate a short circuit)

- the resistance across the two wires -- should be very small but finite (<5 ohms -- the resistance of the coil of wire wound around the iron cores of the stator)

 

It the above check out, then by adding a voltage regulator, you can again get on-tractor charging for your battery!

I'm getting 20.5 VAC at full throttle, so it seems to be ok per pfrederi's post, no shorts on either wire and about 1 ohm of resistance on the windings, so I guess it worth a try, the question of course is what regulator to buy, and where/how to mount it on a Raider 12?  Any suggestions for a model? I do have a regulator on a non-running 1054 with a gen/starter, the 1054 also has its electrical system hacked and its regulator is not wired to anything, so its suspect.  I'm inclined to buy something new rather than mess with something salvaged, that's mounted on a generator. I think the picture below screams, buy something new!

 

 

Edited November 11, 2023 by DCwom

[Handy Don 12,282]

Believe it or not, the type of voltage regulator shown in your picture is usually very well sealed against the elements and its working parts may be pristine inside! I would not abandon that one for use on the S/G 1054 but rather clean it up and test it. Clearly, though, the terminals and external wiring need some attention!

 

Someone with specifc knowledge of the Charger will chip in and suggest the correct regulator. My instinct would be to post a “Want” in the classifieds as several vendors and members may have what you are looking for.

Edited November 11, 2023 by Handy Don

[pfrederi 17,743]

Can't use that regulator for the Charger

You need one like this.  note yours is a 10 amp system but you can use a 15 amp regulator  (usually cheaper easier to find)

 

Mount it inside the hood stand

 

 

[Handy Don 12,282]

8 minutes ago, pfrederi said:

Can't use that regulator for the Charger

You need one like this.  note yours is a 10 amp system but you can use a 15 amp regulator  (usually cheaper easier to find)

 

Mount it inside the hood stand

 

 

  

 

The two wires from the engine go to the outside two terminals of the regulator (interchangeable because it’s AC ). The middle wire goes to the battery “plus”, typically via a 15 amp fuse.

The battery negative and the regulator housing must be solidly electrically grounded. There MUST be a battery connected for the regulator to function.

Edited November 11, 2023 by Handy Don

[DCwom 78]

 

2 hours ago, Handy Don said:

The two wires from the engine go to the outside two terminals of the regulator (interchangeable because it’s AC ). The middle wire goes to the battery “plus”, typically via a 15 amp fuse.

The battery negative and the regulator housing must be solidly electrically grounded. There MUST be a battery connected for the regulator to function.

Look what I found! I've never looked up under the dash, I'm not sure how to get my hand up there? Time to get some wires to see it it works.

 

 

 

 

 

Edited November 11, 2023 by DCwom

[pfrederi 17,743]

Lots of corrosion I would take it out clean it up  need a good ground.... the terminals should be labeled  Engine wires go to AC the BAT goes to ignition switch

[wallfish 17,023]

2 hours ago, DCwom said:

Any suggestions for a model?

https://www.tractorsupply.com/tsc/product/tisco-voltage-regulator-vr1820

[DCwom 78]

Ok, an update.

 

I wired up the old regulator and got nothing, about zero VDC. A new regulator arrived today from Amazon and after wiring it, all I got out was about negative 2.5 VDC, at full throttle, no load. I slapped a 10 ohm load resistor on it and the voltage went to zero. The negative voltage has got me scratching my head, I double checked my meter connects and they were correct polarity. The DC voltage did vary as the engine speed varied, so there seems to be some correlation with the AC.

 

The 2 AC leads from the engine read about 20 VAC and are attached to the AC leads on the regulator, I've got a bolt and wire from the regulator case to ground and put the meter across the regulator output and ground at the regulator case, seems pretty straight forward. I suppose the new regulator could be bad, but that would be just bad luck.

 

Any thoughts? Is 10 ohms too large a load, it would be about 1.2 amps, but this is a 10-15 amp regulator.

 

[gwest_ca-(File Mod) 11,072]

Turn the key to the run position with the engine not running. Do you have battery voltage at the 12VDC terminal on the regulator? You should have.

[DCwom 78]

3 hours ago, gwest_ca said:

Turn the key to the run position with the engine not running. Do you have battery voltage at the 12VDC terminal on the regulator? You should have.

I'm not actually that connected at the moment, the regulator is isolated, connected only to the engine AC wires and a voltmeter on the regulator output. Also my key switch doesn't have a "run" position, I have a separate switch for engine (coil) on/off, the key switch just triggers the starter solenoid. Here are a couple pictures of the regulator connections. The yellow wires go to the engine stator and the black wire is grounded to the frame.

[Handy Don 12,282]

As noted earlier, it is MANDATORY to have a 12v battery (even one in not great condition) connected to the DC out terminal for the regulator to function properly. It’s likely that both regulators are working.

10Ω is not a problem as a load, but recognize that as long as it’s connected, it’ll be drawing current from either the stator (if it’s providing enough voltage) via the regulator or else the CONNECTED BATTERY.

Edited November 17, 2023 by Handy Don

[gwest_ca-(File Mod) 11,072]

Add a jumper from the DC+ to the battery (+)

Check voltage on that wire with engine not running.

Start engine - voltage should increase indicting it is charging.

 

The regulator must see battery voltage before it can regulate the charge current. Powers the regulator on so to speak.

[DCwom 78]

21 hours ago, gwest_ca said:

Add a jumper from the DC+ to the battery (+)

Check voltage on that wire with engine not running.

Start engine - voltage should increase indicting it is charging.

 

The regulator must see battery voltage before it can regulate the charge current. Powers the regulator on so to speak.

I put a jumper to the battery and yup I got 12 volts with the engine off and 13+ something that varied with engine speed when it runs. That's good enough for me to wire it in and mount the rectifier/regulator tomorrow morning.

 

This has got me to thinking that the rectifier/regulator isn't a voltage regulator at all, but a current regulator, and its not acting like a dedicated battery charger would.

 

I assume that the rectifier DC output should wire to the coil side of the on/off switch so that the rectifier output is disconnected from the battery when the engine is off.

[Handy Don 12,282]

2 minutes ago, DCwom said:

rectifier/regulator isn't a voltage regulator at all, but a current regulator,

Good news on the functioning regulator.

It regulates both current and voltage. Many WH tractors’ stator AC output can run up to 40 VAC. That would cook a battery quite quickly.

 

2 minutes ago, DCwom said:

assume that the rectifier DC output should wire to the coil side of the on/off switch

I strongly recommend not making assumptions. Instead, download the wiring diagram for your tractor from our files and follow it and learn from it.

[DCwom 78]

Just to close out this thread, thanks to everyone for their help. I've got everything wired & mounted, time will tell if this keeps my battery up, but the voltmeter indicates it should. The hardest part was working by feel to mount the regulator up under the dash area, I ended up getting some extra long carriage bolts for a better "feel", then used a deep socket.