VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Battery Charging issues

Running the 6 volt battery on my 1929 (actually 1930) 194 engine.

I have been having to charge the battery.

Current status:
6 volt battery,
6 volt coil,
943-J Generator with Cut Out Relay.

Measurements with cold engine not running:
6.38 volt at Battery,
6.38 volt at Generator Relay.

Measurements with engine running with lights OFF:
~2.5 discharging at ammeter,
~6.28 volt at Battery,
~5.98 volt at Coil,
~5.12 volt at C.O. Relay.

Measurements with engine running with lights ON:
~13 discharging at ammeter,
~6.19 volt at Battery,
~5.30 volt at Coil,
~4.45 volt at C. O. Relay.

I know I should be seeing higher readings between 7-8 volts while engine is running at the battery, correct?

What should I check first?
I was going to polarize the generator first but was not sure with the cut out relay. Should I run a jumper across the terminals? Do
i do this with the engine off and wires still connected or disconnected?

Thanks in advance.

Bob

Yes. The generator output with the car running and the lights off should be around 7.5 to 8.2 volts. From what you describe it sounds like your generator is not charging.

On polarizing, we have had a zillion discussions on Chevy Chatter regarding polarizing in the past. Anyway, with all wires attached and the electrolock off, attach a jumper wire to one terminal on the cutout. Then touch the other end of the jumper wire to the opposite terminal on the cutout. You should get a spark. Do this a couple of times to make sure that the generator is polarized. If the generator still doesn't have any output then you will need to check the generator as to why there is no output.

Thanks Junkyard Dog. I will try that. I assume when you say "electrolock off" you are saying ignition in the off position?

That is how I thought the jumper was to be connected. And yes I will only connect the second end of the jumper for a less than a second.

Thanks.

Bob

Yes.

I polarized the generator and am still getting low voltage output. 5.39 volts with lights off and 4.39 with lights on.

Next step I assume is to try adjusting the third brush.

How much movement of the third brush can I expect to adjust to reach 7-8 volts?

When I reach 7-8 volts at the battery on my multimeter (with the lights off), should I fine tune to zero reading on my ammeter (with the lights on)? As long is it is below 10 amps with lights off?

Hope this makes sense.

Bob

Before you adjust the third brush clean the commutator on the armature. Once clean, then adjust the third brush so that it is about 4 comm. bars apart from the main brush. At that setting you should show a max. of around 10 amps, fast idle, lights off. If you are getting that on the car's amp meter then you are good to go. If you are still showing low voltage and a discharge on the amp meter, check the cutout to make sure that the points are closing. If the points are closing and still no charge, clean the points on the cutout.

If none of the above works then it is time to rebuild your generator.

shiney up the armature and check the brushes for wear/contact, would by high on my list. jim

Back working on the '29 after a little layoff. Took the generator in and had it examined. The generator was rebuilt with a new bushing, bearing and cut out relay. Electric shop said everything else looked real good.

Installed the generator last night and had the car running in no time.

Battery was really weak but started the car. The voltage at battery now was 6.18 volts with engine running. About the same as before repair. Reading at Ammeter was very similar to above before repair.

Going to charge the battery overnight and see what results I have tommorow.

Just curious, does a low charged battery effect the recharging numbers versus a fully charged battery? In other words, will I get a higher number than 6.18 volts when the engine is running with a fully charged battery?

Will I be expecting to adjust the third brush after getting the battery to somewhat full charge? By increasing the voltage I will be increasing the amps to the ammeter at the same time.

Thanks.

Bob

You have to run the engine for a while to get up to the 7 volt range.
Even on my modern car the vlotage reads just over 12 volts until the engine runs for a while and then it gets up to 14 volts.

If you watch an amp meter and volt meter when you start the car amps will be high and volts low, as the amps come down the voltage will go up, as Gene stated.

Thanks CN. Interesting. I will give that a shot tonight also. All I did was run a fast idle for about 5 minutes.

Bob

I checked my numbers for voltage and amps with my battery fully charged. With the engine running, I have no changes to the Voltmeter (~6.28 Volts) at the battery and dash ammeter reading (~-2 - 0 Amps).

With a new cut out I was expecting better results. Could it be the cut out points?

I adjusted the third brush quite a bit with no changes to the above. Not sure what I am missing. Any thoughts?

Bob

After you installed the rebuilt generator did you re-polarize the generator?

Thanks Junkyard Dog. I forgot to try that. I will tonight.

Bob

Whenever you remove and reinstall the generator you always should re-polarize the generator because if it loses polarity it will not charge.

Thanks Junkyard Dog. I did not know that.

Bob

I polarized the generator through the cut out and adjusted the third brush (away from the engine) with no change to charging. Could it be I need to polarize the generator while jumping from the positive lead on the cut out to the third brush lead directly at the brush?

You only need to polarize the generator from the "Gen" terminal on the cutout to the "Batt" terminal on the cutout.

Thanks.

I tried polarizing again with no changes to charging.

I checked for any parasitic draw loss and it came out 0.00 on the multimeter. With the lights on it drew -4.70 amps at the mulitmeter and a major discharge at the ammmeter.

Since the ammeter seems to be working fine in the way of discharge, I assume there is an issue with the lead from the generator cut out to the battery. Not ever showing movement to the charging side of zero at the ammeter, even after adjusting the third brush.

I have in the last couple of months repaired a (burned in two) wire from the battery to the ammeter. I think this was due in fact to the previous owner running a 12 volt battery. Of course now I am running a 6 volt battery.

I will check said lead for a short. Is there an easy dependable way to test the lead going from the generator cut out to the ammeter?

What would happen if I disconnect the + side at the cut out and start the engine? Any damage?

Maybe the best thing is to disconnect the existing lead and run a temporary lead from + side of the cut out relay to the ammeter and see what that does.

Just curious.

Bob

sounds like a quick simple solution to eliminate said wire. to test the said wire for a short, have to disconnect both ends and test for continuity. but if you get the same results with a test wire of appropriate gauge and length, then you know it has to be something else.

If you disconnect the + lead from the cut-out,do not let the engine run above idle speed.If you run it any faster than idle speed,the output voltage produced by the self exciting 3rd brush generator will burn it out.

Thanks guys. I will disconnect the current lead at both ends and run a test lead to see what happens. I will not run it with the cut out and generator disconnected.

Bob

The saga continues. I ran a separate jumper as mentioned above. I also polarized the generator. I am still getting 6.28 volts at the battery with the engine warmed up and the ammeter continues to stay around ~-2 amps unless I turn the lights on then it goes to ~-13 amps.

I again wonder if the ammeter is bad. If the ammeter is not functioning correctly then therefore it is not sending additional power to the battery.

How do I check the condition of the ammeter? As usual, any help would be appreciated.

Bob

Your problem is the generator.

Thanks Chev Nut. I hated to read that after spending $65 do get it repaired the other day. They told me to let them know if I have any issues. I guess I will.

Bob