Why voltage regulators fail

[DickB]

I'm on my 4th VR. Call that 5 if you'd count the one I returned as it failed in a day. The original lasted for years. The failed ones with one exception were foreign made...in India I believe. The last to fail was USA made and was just over 2 years old.

I talked to John Brillman (brillman.com) who sold the USA made VR to me; he felt the failure was due to the 6v battery not being maintained and, offering me free shipping (nice of him, I thought) on a new VR, he also offered a suggestion. John felt that a trickle charger was essential to the tractor's set up, and not having one caused the generator (I hope I get this right...) at starting up to push a really oversized jolt of electricity through the VR. And that jolt overpowered the VR for the moment; repeated jolts like this brought about the VR failure--in my case it took just over 2 years. That seemed to me to be a thoughtful considered analysis and I went with it.

Now I have a new VR and a trickle charger (Schumacher SC1319 1.5A 6V/12V Automatic Battery Maintainer). When the trickle charger was hooked up the charge light (yellow) was on for the better part of an afternoon; sometime around dusk it turned to green (trickling?) and in the morning was pulsing on/off green (the maintance mode). Prior to hooking up the trickle charger I'd only run the tractor with the new VR and, BTW, a new battery, just to run through the flow chart #8 to determine what was wrong and to check out the ammeter once the new VR was installed and polarized. So the battery...even with the generator going and the new VR in place still seemed to be a bit in need of a charge. That's what the trickle charger was doing with the yellow light. ...I think....

So, I'm hopeful this will take care of my VR issue. Did I get it right? Other things that go wrong? Of course.....

[ricky racer]

A trickle charger and a battery maintainer are different. A trickle charger puts out a continuous low amperage charge and can eventually over charge a battery.
A battery maintainer monitors the batteries charge and charges once the batteries charge drops to a certain level. Once a full charge has been achieved the maintainer goes into float mode until the battery requires a charge again.
A battery maintainer will help a battery last last much, much longer easily paying for itself.

[TallCoolOne58]

I have the same 'trickle' charger, that I originally purchased for atv batteries. Works great. My Cub is 6 volt, and after starting and running it, I always hook it up. Solid green light=fully charged, that is when it goes into 'float' mode, and monitors battery state of charge, and only charges when necessary. Solid yellow=charging, which I only see if I start and run my tractor for a short period (very rare). Great for winter if you plow, battery always ready to go. Keeps your generator and VR on Easy Street, and prevents your battery from freezing. I am not surprised it took awhile for your battery to fully charge, but you should check for a 'parasitic' discharge, a short somewhere discharging the battery.

Many people make the mistake of thinking a generator or alternator is a substitute for a battery charger.

I always fully charge a new battery before hooking up and putting into service (if you don't, it will never accept or be fully charged). Also before and after storage. If left in vehicle to store, at the very least disconnect the ground cable, fully charge, and leave the ground cable disconnected until recharged and put back into service. They will last a long time this way.

[TallCoolOne58]

Edit: it should also be noted that the voltage regulators used on these older tractors regulate maximum voltage, and NOT maximum amperage. Upon start-up, a voltage regulator will allow current flow (amperage) until the voltage rises above a certain amount, for a 6V system approximately 7 volts. In the meantime, the generator is working hard outputting all the current that the VR is allowing.

[radioguy41]

I'm on my 4th VR. Call that 5 if you'd count the one I returned as it failed in a day. The original lasted for years. The failed ones with one exception were foreign made...in India I believe. The last to fail was USA made and was just over 2 years old.

I talked to John Brillman (brillman.com) who sold the USA made VR to me; he felt the failure was due to the 6v battery not being maintained and, offering me free shipping (nice of him, I thought) on a new VR, he also offered a suggestion. John felt that a trickle charger was essential to the tractor's set up, and not having one caused the generator (I hope I get this right...) at starting up to push a really oversized jolt of electricity through the VR. And that jolt overpowered the VR for the moment; repeated jolts like this brought about the VR failure--in my case it took just over 2 years. That seemed to me to be a thoughtful considered analysis and I went with it.

While I agree a battery maintainer is very helpful I'm not buying the explanation for failure. Original VR's have lasted for many years (my jeep had the original 1950 (dated) VR), long before maintainers were even thought of, and now the new ones fail sometimes within weeks and it's because the battery isn't fully charged? I'd take that with a grain of salt. If the VR can't handle that initial surge, especially at the low RPM's of a Cub, it isn't built right.

[Larry in WNY]

My father had a battery maintainer on his Farmall M and over time it boiled all the water out and destroyed the battery. Case IH replaced it under warranty fortunately.

Larry

[ricky racer]

My father had a battery maintainer on his Farmall M and over time it boiled all the water out and destroyed the battery. Case IH replaced it under warranty fortunately.

Larry

That sounds like a trickle charger or a defective maintainer. Certainly not the norm. I've got at least a half dozen going all the time. They save me a fortune in batteries.

[inairam]

I have purchased one from Brillman as well that failed. I just do not think they know how to make them to last.

I have switched to electronic VRs because of the high failure rate and have been very happy. Unfortunately, my source Clover that I have been recommended went out of business. I have found another source in the UK but have not tested it yet.

[Eugene]

That sounds like a trickle charger or a defective maintainer. Certainly not the norm. I've got at least a half dozen going all the time. They save me a fortune in batteries.

I have 3 or 4 battery maintainers going all the time. No problem.

On the defective voltage regulators, change the tractor over to a 12 volt alternator.

[jsfarmall]

My 6v cub has a cutout relay instead of a voltage regulator. Are these prone to failure like the regulators are?

[Eugene]

My 6v cub has a cutout relay instead of a voltage regulator. Are these prone to failure like the regulators are?

The cutout has fewer mechanical, electrical parts, than a regulator. So less likely to fail.

[Waif]

What incentive exists to build durable regulators?

Competition for niche markets today only confirms there is nothing that cannot be made cheaper ,and sold for more money.

[DickB]

Edit: it should also be noted that the voltage regulators used on these older tractors regulate maximum voltage, and NOT maximum amperage. Upon start-up, a voltage regulator will allow current flow (amperage) until the voltage rises above a certain amount, for a 6V system approximately 7 volts. In the meantime, the generator is working hard outputting all the current that the VR is allowing.

Here we go. This seems to me, an electrical illiterate, to be echoing John Brillman's assertion that the Cub without the battery maintainer eventually does serious damage to the VR. What is that damage? Well..having a bunch of VRs without a future, I pulled them apart (wife interested in the copper wires in the coils). What I found was pitted points. The coils seemed fine, and that's all there is to the VRs. In the past I tried to save VRs, being accidentally on the right path, by dressing up the points. But I no luck with it. There's no info on setting gaps and it is really difficult to view the status of the points. So I'm staying with the battery maintainer as the device that will keep the battery up to its maximum and hope that helps (somehow) the generator to not be obliged to overpower the VR.

Is TallCoolOne 58 on to it? Does this mean that the generator is pushing excess (is it) amps (?) to the VR and that causes pitting? If the battery is indeed up to snuff does that keep the generator from pitting the VR? Oh boy, I should have been forced to study electricity in high school.

[Glen]

Hi,
Below is a page from the Cub service manual showing adjustment specs for the voltage regulators.
A little hard to read, it is up and down on the page.
These are the original Delco regulators. The modern replacement regulators might have different specs.
3 are 6 volt regulators, used over the years, and the 4th one looks to be a 12 volt reg.

http://www.farmallcub.info/manuals/gss- ... 009-04.jpg

My opinion is some of the new replacement regulators have points that are not hard enough metal, like Dick said, his points are burned and pitted.

Only the on and off set of points open, when the engine is off, to shut off the charging system.
The other set of points controls the output of the generator, it is closed all the time by the small spring. The more pull on the spring, the more output the generator will produce.
The output should be tested when the engine is running, using an automotive test voltmeter.

[TallCoolOne58]

A voltage regulator usually contains a cut off relay, and a voltage relay. Later more sophisticated ones also had an amperage relay. The cut off relay is an electromagnetic switch to disconnect the battery from the generator when tractor is off (points open). This keeps the battery from being drawn down. Start the tractor, electrical current present, points close allowing current to flow thru the regulator. The voltage relay is also simply an electromagnetic switch. It is normally CLOSED (points closed), unless the voltage rises to a point where the magnets overcome the spring pressure, on a 6 volt system normally in the neighborhood of 7 volts.

Amperage= current flow, Voltage=pressure. You cannot have peak amperage and peak voltage at the same time. Current flow= voltage drop, less current flow=voltage rises.

When you start your tractor, you have used some stored electricity in your battery. You will have lower voltage because virtually instantaneously the voltage regulator is allowing current flow to recharge the battery, plus the amp draw from battery ignition, if you have it. The battery will only accept a certain charge, so as current flow slows voltage rises. At a preset voltage maximum point, (about 7 volts on a 6 volt system), the voltage regulator opens it's points, and current stops flowing. Actually it does this many times per second, especially after you have run your tractor for a few minutes and the battery is recharged.

There is no great way to 'save' a voltage regulator. Most of us don't own a temperature and humidity controlled garage. That is known as a museum.

Darned if you do, darmed if you don't. If you don't use your tractor, moisture and corrosion will take it's toll anyway. If you do use it, you increase wear and tear.

If your tractor is used often, at least once or twice a week, I wouldn't sweat a battery maintainer. It does give you an edge in cold weather, and helps prevent a slow discharge. A lead acid battery won't take a deep discharge, and recover well.