22 months ago I pulled the engine out of my '32 coupe and had it completely rebuilt. I kept a tender on the battery and it appeared to keep it charged. We started the engine 2 days ago for the first time since August 2016. We had to recharge the battery. The next day the battery was dead again. I'm not really surprised that the battery needed replacing. I bought a new battery. I bought an 8-VOLT BATTERY. Everything seems to work better than the old 6-volt battery. The engine cranks over very strong. The lights are just a little brighter. The amp meter reads 7 to 12 amps. I'm looking for any other opinions about using an 8-volt battery - good or bad.

There have been many discussions here in the past regarding an 8 volt battery. You can do a search and probably come up with some of the previous discussions. Anyway, the overwhelming opinions in the past are not to use an 8 volt battery. One of the main concerns is the generator output for an 8 volt battery. I would suggest that you return the 8 volt battery and install a 6 volt battery with a minimum CCA of 600. Also install a 00 or a 0000 positive battery cable.

Question...............how does a generator that produces like 7 volts keep an 8 volt battery fully charged? A system with a voltage regulator could be adjusted for voltage but not a pre-volt regulator system.
Or for that matter a battery charger that is designed to charge a 6 volt and/or a 12 volt battery.

With an 8 volt battery the voltage regulator needs to be adjusted to charge more, this can be done if you know what your doing. The light are brighter because they are rated 6 to 8 volts, but you will burn bulbs a lot more. Don't crank the starter very long or it may get hot and fail some day. My 6 volt cars start and run like they should. My last battery lasted 10 years and never burned a bulb or replaced a starter or generator.

Toss the 8 volt and get a good quality 6 volt battery. The switch to a 8 volt merely masks the problem not remedy it.

A well cabled, tuned and adjusted engine designed to run off a 6 volt doesn't need no stinkin' 8 volt.

Just my opinion.

Charlie

I agree with Charlie! Surprised???

You are temporarily hiding the real problem that will catch up with you later. A good 6 volt battery, clean grounding, and proper size cables work great.

Going back to my question how does a 6 volt system generator charge an 8 volt battery on a car that does not have a voltage regulator. There are no adjustments that can be made.

"Olsarge" has a 1932 Chevrolet and if it has the stock charging system there is no voltage regulator......just a cut-out relay.

Mercy! Don't get me started.


Charlie, did you intend that as a pun?

I appreciate all the input. Did you ever ask a question kind of knowing in the back of your mind what the response would be? Well, i pretty much knew what you guys were going to say. That being said, I'm going to keep the 8-volt battery, at least for now. I was already aware of most your concerns. The only real issue I see is the lights may have a shorter life. That's not a major concern as the car is rarely driven at night. As far as the generator, the 6-volt generator with the cut-off switch will charge the battery just fine. Several Model A friends have been running 8-volt batteries for years without issue. The starter doesn't mind the 8-volts as long as you don't grind on it. I've jumped this car off with a 12-volt battery without a problem. The other item is the horn. Again, if you don't hold it down all is good. With the 6-volt battery with an excellent ground the lights were never very bright and were always kind of yellow just like every 6-volt car I've ever seen. Please don't get me wrong. I truly appreciate all your expert advice. That's why I asked and that's why I joined the VCCA over 10 years ago. I will keep you posted. If I suffer any negative consequences I'll surely let you know.

The headlights will be bright on 6 volts if the reflector has been replated. The best solution I have found is to have them nickle plated and then aluminum vacuum sealed. When I restored my car 18 years ago I had the reflectors polished. After a couple of years the silver on them had dulled again. A few years ago i did the above and now they are bright and no yellowing. I may be wrong but I believe the maximum voltage you will get out of a 6 volt generator is 7.8 volts .

I agree. With vacuum sealed aluminum reflectors the 6 volt headlights are as bright as sealed beams making an 8 volt battery totally unnecessary.

Well, I agree with Charlie on this subject ...... a well maintained 6 volt system works just fine.

This is 1 of only a few of Charlies posts that makes sense to me as well.
Tony

olsarge,
it would be very interesting and educational if you could tell us what the charging voltage is when it is running and what the voltage is with the engine not running.

I may have said "don't get me started" in another forum but I don't think so in this one. I'm not smart enough to come up with a decent original pun.

Charlie

Sorry I just saw your post. It's 8.5 volts with the engine not running. I haven't checked it when it's running. I'll try to do that and report back.

The 3 brush generator on open circuit will produce a high voltage depending on speed, at least 30 volts. this high voltage causes a higher current to flow thru the field coils producing an even higher voltage. Eventually something gives in and usually the field coils burn out, Early 3 brush electrical systems had a fuse in the field circuit to prevent this from happening, blown fuse no field current and no output voltage. A 3 brush can easily charge an 8 volt battery but would need a voltage regulator adjusted to 10 volts to reduce the current once the battery is fully charged. The limitation on the generator is the heat produced in the armature due to the charging current which is usually limited to 20 amps. The 6\8 volt headlamp globes have a life of only 100hours so running them at 8 volts will reduce their life even further.

Ok. I checked the system this morning. With the engine at an idle the voltage at the battery reads 8.5. I checked on either side of the cut out switch and it also reads 8.5 volts. The ammeter reads 8 amps at idle and about 12-14 amps under acceleration. I don't have a tach so I don't know the RPMs under acceleration.

I can guarantee that it is only a matter of time before 14 amp generator output will begin to melt the solder in the armature. Those generators do not have a vent or enough air flow to keep the temperature down at the higher outputs.

I totally agree! 14 amps on that generator is way too high. Should have a max. output of about 10 amps.

Thanks guys. I will adjust the third brush to give a max of 10 amps at speed. I'll update this post when I do.

Good move. 10 amps is plenty to take care of any requirements unless you have halogen replacement bulbs or another other high draw component.

No, the car has all original lights. I wired the cowl lights with the headlights but that's not an issue. I had the generator rebuilt two or three years ago. Then 22 months ago I pulled the engine for a complete rebuild. I was told to set the generator to 7 to 10 amps. It's 7 amps at idle. I'll set it for a max of 10 amps and disregard the idle amperage.

I set my generators for 6-8 amps at speed. Don't have a problem with battery running down unless I drive an extended period with lights on (which I occasionally do to keep for over charging the battery). Higher amperage boils the water out of the battery and reduces the battery life. If the underside of the cell caps is black then you are over charging.

Ok. I found a document titled Chevrolet Confederate Series BA and Series BB Delco-Remy System. I tried to take a picture of it and upload it here. I couldn't figure out how to do that so I'm typing it out for you guys. I would very much appreciate your comments.

GENERATOR : Model 943-J. Third brush regulation. To adjust generator output, loosen small round headed screw on commutator end plate, take off cover band, shift third brush counter-clockwise to increase or clockwise to decrease charging rate, tighten the locking screw. Rotation counter-clockwise at commutator end. Maximum charging rate 18 amperes (cold) at 8.2 volts reached at 1700 R.P.M.

GENERATOR DATA
Cold Test: Amperes 16-18 - Volts 8.2. - R.P.M. 1700
Hot Test: Amperes 11-13 - Volts 7.55-7.85. - R.P.M. 1750-1850.

These numbers seem to be significantly different from what everyone is telling me.

Please comment.

As stated several times above, since the 943 J generator is unregulated the max. generator output should be 10 amps. The specs. above are used on the generator test bench but on the car the output should be 10 amps max. You can set up your generator to the 18 amps as shown on the spec. sheet but don't expect your generator to last long when the generator armature starts to throw solder and your battery boils because of the constant overcharging. Again, on the 943 J generator 10 amps is max.

The above amps are at the generator proper. If you are going by the ammeter one or two amps are being consumbed by te ignitin so with 10 amps on the ammeter the generator is actually producing 12 amps.Also test is made with generator hot.

Like with any third brush system, you have to adjust the current (via the third brush) in such a way that your battery does not get cooked too bad. What this means in plain English is that you would NEVER set to the maximum rated current. Since there is no voltage regulator you have to pay attention and dial it back, way back.

The goal is to keep the battery full without boiling it. You guess, based on your driving habits. If the battery goes dead or boils,you crank it up or down a little (at the third brush) and try again. No matter what you do it will never be right all the time. Such is life with a third brush.

P.S. If Junkyard Dog says it will overheat and throw solder at something over 10 amps, I believe him, no matter what the book says.

Everything you guys said makes sense. It's one thing to test the generator to make sure it's working properly. It's something else to adjust it so it's doing it's job. I'll set it at 10 amps. I know this topic has been beat to death in dozens of threads. Thanks for the help.

Ok. That was easier than I thought. Third brush set at 10 amps under acceleration. Doesn't seem to matter at what rpm over about 1200 to 1500. It goes to 10 amps and stays there. Drops to about 4-5 at idle. Drops to 0 with parking lights on. Drops to discharge with headlights on. Does that sound right?

Yep, that sounds correct. With the lights on the discharge will vary from -3 to -5 amps at idle depending upon the resistance of the wiring and etc.

Thanks Dog. I feel pretty good about it now. Just one more question and I'll shut up. Doesn't that mean with the headlights on and discharging 4-5 amps the engine is running off the battery and will kill it over time? I do drive the car at night but no more than 10 or 12 miles.

The -3 to -5 amps discharge is with the engine running at idle. At driving speed with the lights on the amp meter should show around -1 amp discharge to 1 or 2 amps charge. On tour guys will drive with their lights on from time to time so that the battery will not get overcharged and boil.

Ok, thanks. And thanks to all.

With a 1-3 amp discharge you can probably drive about three days before the battery is so low the car will not run.

With a much more modern car with 12v, fully charged battery and alternator not charging I have driven for 3 hours at night before the lights were ineffective. I havent been unfortunate enough to need to try this on a 6v system though.
Tony

Teacher: "Children, children, please take your seats. Class will come to order. We're going to have another lesson on Chevy 6-volt generators."

Olsarge: "Teacher, teacher, I have a question. On my 1932 Chevy the tab says 946-C. I know it's not the correct generator. It belongs on a 1936. Is there any appearance or functional difference in the 943-j and the 946-c?"

Teacher: "Very good question. Junkyard Dog, would you please explain the difference between the two generators in both appearance and function? Anyone else can comment too."

Teacher: "Johnny turn around and leave Sally's pigtails alone."

Hey, Teach! Teach!
I can answer that. The original 943J generator was not vented, did not have a fan next to the pulley and only one wire coming out of the case. That wire went to the cut-out. It was the power wire from the generator to the battery. Later generators had vents in the end plates and a fan to move air through the generator. They were capable of higher outputs because the fan and vents kept them cooler than if they were closed. The power output for the 943J was regulated by a "third" brush that was installed between the other two brushes. That brush controlled amount of power to the field coils, therefore the magnetic field and output. If the generator was intended to be externally regulated the wire to the field coils was taken out of the generator to a regulator mounted on a fender, core support, firewall inside the engine compartment or to the light switch. It is the light switch connection that confuses a bunch of people.

Hey, Teach I see the Dog digging up a bone. Nope it is a beer can. Silly dog that can is empty. When he realizes his mistake he will be here shortly. Got to stop at the fire hydrant first.

Hey Teacher!!! Will you get that Dippy Chippy to pay attention in class instead of looking at Laura May's boobs so that he will know what is going on in class? If Chippy would have paid attention like he should he would have noticed that the Mutt was burying the empty beer can and not digging it up because the Pooch drank all of the beer outta the can first! Next the fire hydrant stop to see what is going on there.... that is if the hydrant hasn't been moved since the Dog was there last.

Yep, the description that Dippy Chippy presented above pretty much explains it all. Class dismissed!!

Teacher: "Chipper, you move to the head of the class. Now read all the posts above and tell the class if that changes any of the settings about the amperage output. Should the third brush be readjusted to higher for the 946-c than the 10 amps specified for the 943-j? I'm sure Junkyard Dog will be along soon. I saw him chasing a squirrel up a tree."

Sorry Dog. I guess you came in while I was writing on the black board. For being tardy write "I will not chase squirrels" 100 times.

Teach!
Unless you have an issue with the battery losing charge there is nothing good that comes from upping the output. In most cases 4-6 amp output is far better than higher values. It will keep the battery charged (except for multiple very short trips) and not over charged. Higher outputs will overcharge the battery and reduce its life. Guess the Dog has been "burying" too many cans.

Thanks Chipper. You can skip the test on Friday. You already have an A.

The Pee Dog agrees with the Dipper Chipper........less output is better than more output.

Gotta go bury some more cans.................

Without a doubt we have run the battery down in this thread. The best solution is to use the correct 6-volt battery and correct anything on the car that hinders the correct operation. That will solve most of your problems.

In view of the above I will lock this thread.