1928 Powerhouse charging

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00fxd

Member
The battery in my '28 is very old and not at all serviceable. It will hold volts but certainly has no cranking power. My intention is to operate the car by hand cranking only. When running I notice that the charging system is supplying up to 18v!.
Is this to be expected because of the bad battery?
Thanks, Frank
 
18v will blow every bulb in the car and possibly damage the generator, coil and horn. A good working battery maintains the correct generator voltage. Buy a new battery.
 
I know pretty much nothing about powerhouse generators, but looked up a post from Tom Wessenberg, who knew everything about powerhouse generators, and he said that there is a set screw that needs to be loosened in order to adjust the 3rd brush on a three brush powerhouse to adjust voltage. But having said that, I would second the suggestion from ndnchf to just get a new battery and go from there. Working powerhouse generators are hard to come by, so don't risk damaging your generator.
 
Mike - I'd like to offer a slight clarification. Adjusting the position of the 3rd brush does indeed change voltage. But that voltage change is to the field coils, not generator output. The increased voltage to the fields increases their magnetic field strength. While there is a slight increase in generator output voltage, this in turn primarily increases the generator's output amperage. which is read on the ammeter.

Steve
 
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Thanks for the replies fellas.
It is essentially a new battery. 20 or 30 starts on it over the last 10 years.
So IMO buying batteries for this kinda of service is quite wasteful. Not only financially but I think more environmentally. I wonder if there is any work around ideas for this situation?
Hand crank starting this car is fun and easy for me.
 
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The battery is what regulates the 3-brush generator. With a bad battery, there is nothing to regulate the voltage.

Go get a new battery or disconnect the generator and run either on what battery power there is left or a 6-volt lantern battery. Model A vehicles can not function well with a bad battery. It will kill a generator or overwork an alternator if the alternator even come on line.
 
Thanks rotorwrench. That should work. Takin' the old girl [unrestored touring car] out to a meet this weekend - always a hit.
Frank
 
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the output of the generator has to be grounded to prevent burning it up due to over voltage if you plan on disconnecting it
 
Kurt in NJ said:
the output of the generator has to be grounded to prevent burning it up due to over voltage if you plan on disconnecting it
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I was thinking along those lines as well, but me and electricity have never been close friends, waited for someone who actually knows about this to say something.
Question: I know that running a generator without being hooked to a battery will cause the output to go waaaay high, thereby burning out the generator.
So, simply grounding the generator output back to the generator case will not damage the generator when running? I never knew that. Thanks for the info.
 
Mike Peters said:
I was thinking along those lines as well, but me and electricity have never been close friends, waited for someone who actually knows about this to say something.
Question: I know that running a generator without being hooked to a battery will cause the output to go waaaay high, thereby burning out the generator.
So, simply grounding the generator output back to the generator case will not damage the generator when running? I never knew that. Thanks for the info.
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Grounding the output also grounds out the field windings, so the generator will not produce power. No voltage, no current. Nada.
 
Well maintained batteries will last a surprising long time. Katy has the right idea (post # 10). The battery cannot be overcharged or left undercharged. The electrolyte must be kept at the proper level. Charging at 18 volts will fry the battery. You likely will need a new battery. Check all the electrical connections as that may be the cause of the over voltage. They must be bright shinny metallic. And use an electrical grease, available at hardware stores, to prevent future corrosion. You may need an additional ground strap that goes to the transmission, bell housing, engine block, or directly to a starter mounting bolt.
 
Turns out that I have a battery coming. And I like the charging options posted by Katy. Hadn't looked into 6v maintainers - I'm a believer, have them on other 12v cars.
The car gets started a few times a year only, been in the family since '48
Too bad, I wonder what the dirty 30's folks did about compromising the generator when they couldn't afford a battery and so relied on hand cranking...... their old batterys were likely not as bad as the one I have.
Don't wanna hurt the gen that I had rebuilt 30 years ago.
The car gets started a few times a year only, been in the family since '48
Thanks for the ideas all.
Frank
 
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Badpuppy said:
Grounding the output also grounds out the field windings, so the generator will not produce power. No voltage, no current. Nada.
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I don't have any problems, but would like to know exactly how to ground the output of the generator. Would I run a jumper from the cutout output (radiator side) or the generator output (cutout back side) to where? One of the screws that hold the cutout on?

Please explain.
 
Rob Doe said:
I don't have any problems, but would like to know exactly how to ground the output of the generator. Would I run a jumper from the cutout output (radiator side) or the generator output (cutout back side) to where? One of the screws that hold the cutout on? Please explain.
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Run a wire from the generator output to any convenient ground, a cutout mounting screw is a good option.

Do not put a jumper from the output side of the cutout, that would be a dead short from battery power to ground.
 
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