8 volt battery regulator setting

Dad put an 8 volt battery in his 1950 Farmall H some years back. He is almost 90. It does not hold a charge. I told him he probably needs to tweak the voltage regulator higher. I am pretty sure that it has a regulator instead of a cutout as I remember nothing about having to play with the light switch to control charge back when it was used every day, 40 to 50 years ago. Maybe the generator doesn't even charge. I need to talk my brother through it when I know what to actually do. Please let me know what steps to take. He is talking about changing to a 12 volt alternator, but I think that would be a wasted effort. It is used very little now, and only in the summer. The lights have not worked for years, so that is not a concern. I was there today and it would not start. I was going to look at the electrical gauge (probably an ammeter) to see if it was charging. He said that when they need to use it, they pull it to start. That makes me think that the generator is putting out enough power to fire the ignition system. What would the correct charging voltage be. I am thinking around 9.7 to 9.8 volts. Should that be at idle, half throttle or full throttle. With a generator does the speed (rpm ) make a difference at what the charging voltage should be. I don't live that close and didn't have a meter to check the system with me. Please let me know and thanks in advance.

Charge the battery to see if it is worth troubling with. An H will start well on 6v with 0gauge battery cables, and a good battery. If the battery voltage is 8.4 (not connected), and it stays at 7.5 volts while cranking, it will spin the engine. The charge rate might not be as high as you indicate, it would be ideal if it did, but I predict 9.3 to 9.5 on a good day. John T charging system diagnosis *search in the archives) will help a lot, though it is not specific to 8 volts. Jim

Does it have distributor ignition or magneto? Battery could very well be bad if tractor has magneto. Any idea how old the battery is? When you say it wouldn't start is that when trying with the starter or when pulling it?

Measure the voltage at the battery terminals when the engine is running. If it's 9 volts or higher, that indicates the generator is working.

Where is it located in case someone is close enough to give you a hand in person.

I believe it does have a regulator, and yes it would need to be adjusted to get the benefit of an 8 volt battery.

But even if it were not adjusted up, as long as it was charging, it would still keep enough in the battery that it would work. That is "if" everything else were in good working order, as in the starter, cables and properly tuned for good starting.

If you can get it running, and it is charging, yes, 9 to 9.5 volts would be good. A generator does need to be revved up to charge, probably 1/2 throttle or better.

Couple of tractors i did some repair they didnt do anything to the charging system and they had been that way for yrs. Just for fun i checked the batts with a hy and they were ok. Just take reading on the gen when tractor is running and if the lites dont work mite have trouble someplace check fuse those bulbs will be ok with 8v older bulbs said on the box 6-8v.

A 6 volt system will do the job very well, if in good condition with the right battery cables. However, the generator only puts out a few amps. Maybe 10-13 max. When these tractors were used all day long, they had plenty of time to recharge the battery. Now days when we back them out of the shed, drive them across the yard, shut them off and start them again to put back in the shed, the battery doesn't fully recover. Battery life is shortened when not kept fully charged. After parking in the shed, make sure the battery has a full charge. I frequently use a 6 volt automatic charger to insure a full charge. If an automatic charger is not used, do not allow the battery voltage to exceed 7.5 volts.
The greatest advantage of converting to 12 volts, is the alternator. The alternator will provide quick battery recovery. When converting to an alternator, use a 60 amp gauge and you will see that after initial startup, a high charge current. Maybe 30-50 amps as apposed to the 10-13 from a generator.
Alternators can be configured for a 6 volt system, however, I prefer to used a standard alternator readily available from the auto parts store.

Check the battery , see if it is good. Put in [some years back].

12 V LED lights will work just fine on an 8V system. Nominal charge voltage should be 9.2V.
Odds are the battery is done from age and operation at partial charge .

I ordered a 10 watt 4 ohm resistor to drop charger voltage to get it charged. My brother questioned whether jumper cables got put on wrong and reversed polarity. More research to do. Might not get to it before spring. Might need to take to a shop. Surely need to check brushes and bearings or bushings. It has an international distributor.