8 Volt (contd)

[SteveG]

This is my last post from the 8 Volt thread. Just in case some folks missed page 2.
SteveG

Here are the readings I'm getting, with a fully charged 8 volt battery, from the relay to ground.

Low idle - contacts are open - 7.9 volts
High idle - contacts are closed - 8.5 volts

My concern is that the relay will continue to be closed while driving, and maybe over charging the battery.

My generator is rebuilt and the came with a Delco relay. The windings may be burnt because they are blue. Maybe it is a regulator/relay?

Maybe this relay may work. It states 6-12-24 volt. Anybody know?

http://www.ebay.com/itm/Farmall-6-Volt-D100-Cut-Out-Relay-for-A-B-C-H-M-CUB-SUPERS-w-3-Brush-GENERATOR-/261211390220

What do you think about the above readings I took?

Thank you.

SteveG

[chetbrz]

Steve,

In the previous thread you stated that:

"Here's an update. I received the 8 volt Battery Tender and charged to the correct level. The car fired right up."

Were you having issues starting the car.  If you had to charge the battery to get a good start I would think you might not be getting enough charge Maybe the generator is not pushing enough current ?  Please explain.  You mention that the windings are blue, did the generator ever smoke ?

Chet...

PS...   If you click on "Profile" than in the Modify Profile area click on "Look & Layout Preferences" check the box that states: "Show most recent posts on top."  Then you will not have to go to the bottom of the thread to see the most recent activity.  It will show in the reverse order with the new post first.

[imoore]

The cut out relay should be closed while engine is running. Whether at idle or driving. The high volts is what is needed to allow the battery to begin charging. But it is the amps that actually charge the battery. This is were the 3rd brush comes into play. If u are doing short drives, you will require a high charge rate then long cruising speeds. I have mine set to about 4amps. If i require heal lights on  then u increase 3rd brush to give u more charge. That way the battery dosent go flat with extra current draw. 
Having the charge rate to high will cauae overcharge of battery and boil the acid.
To low of charge will undercharge the battery causing it to run flat.
These are all caused by the 3rd brush location. From memory the closer the 3rd brush is to the negative (c/o relay) brush the higher the charge.
Hope this makes sense.
An inductive style amp meter helps when diagnosing charging faults.

[imoore]

Also my cut out relay closes at about 550 engine rpm. But i have my idle at about 650-700

[Old Man]

Not to step on anybody's toes here, but the industry would not have installed,1st, a voltage regulator atop the generator in about 1934 ,and then a current regulator relay in the same box a year or so later, if the 3rd brush was already regulating the charge. The 3rd brush remained but only to set the highest current the generator could provide if it ran across a "dead" battery. Otherwise it would just put out 40 or 50 amps,I guess, and rupture the battery case in a little while. Yes you're correct in having to move the 3rd brush to give an average 3-4 amps during most driving. I knew nothing about the practical application and use of electricity in automobiles when I got my antiques but had a background in electronics. I thought I would set the ammeter to "0" ,or very close to it, while driving by using the 3rd brush. Wrong. After an hour's drive the engine started to buck and jump. Long story short, because the car had been running on it's battery all this time,the battery voltage had started to drop below the point where the ignition system would provide a good steady spark. This is the "balance" I've talked about. So I did indeed end up setting the 3rd brush to provide a small "charge" position on the ammeter and that solved the problem. (This really isn't a charge. The battery finally attains a full charge at some point and the current showing on the ammeter is the current the ignition system and the lights etc. are using. The ammeter actually shows the combination of the 2 currents. You have to divine which one you're looking at. In other words, the first current after starting is the charge current and running current and then at some point the remaining current is the car's "running" current. The battery has been charged and only a trickle current will now flow into the battery to keep the charge up. This for the most part is "invisible".)Today I drive with my lights on for safety and the system is set to provide a "charge" of 3-4 amps with the lights on. I live out in the country and if I think I cranked longer than I usually do to get the engine running, I turn off my lights until I get on the main roads and the charge goes up by several amps as the system is unloaded by removing the lights. These settings also give me lights at night,with a positive "charge", if I stay out late. What I'm doing is what the industry designed into their voltage and current regulators. They alternately jump from a full on generator to putting a resistor in the field winding to cut down the charge current. I just do it manually. The problem with our regulatorless cars is the battery is the regulator,brute force regulator. Technically speaking it is the internal impedance of the battery that regulates the whole system. They eventually installed regulators because it was too "hard" on the battery and cars were being used more at night.                   

[SteveG]

Steve,

In the previous thread you stated that:

"Here's an update. I received the 8 volt Battery Tender and charged to the correct level. The car fired right up."

Were you having issues starting the car.  If you had to charge the battery to get a good start I would think you might not be getting enough charge Maybe the generator is not pushing enough current ?  Please explain.  You mention that the windings are blue, did the generator ever smoke ?

Chet - I never saw the relay smoke. It seems to be running good but I haven't had it out for a long drive to see for sure.
Thanx for the info. about setting the post order.

Old Man - Great info. as usual. I am leaving it alone for the time being until a get some miles in. I problems surface, I will get my hands on an induction ammeter to try to determine the position of the third brush.
Do the voltage readings, in the above post, look OK for a fully charged battery?

SteveG

[racertb]

Wow...after reading several pages on this 8 volt topic, I think I'll stick with my 6 volt like the car came with.

[SteveG]

Probably a good idea!

[Doug]

If you use a good quality battery and keep connections clean you will not have any problem with 6 volt. A friend of mine who was raised in Minnesota reminds me of the days when 6 volt wouldn't crank his car when the temps got below 0. I want be riding around in this car when it's that cold.   

[SteveG]

If you use a good quality battery and keep connections clean you will not have any problem with 6 volt. A friend of mine who was raised in Minnesota reminds me of the days when 6 volt wouldn't crank his car when the temps got below 0. I want be riding around in this car when it's that cold.   

For sure!

I'm going to use the 8 volt 'till I know if it will work or not. If not I'll go back to 6 Volt.

Thanx again for all great comments from everyone. I learned a lot.

This is a great site!

SteveG

[PatrickSmith]

New to this forum but for what its worth I have ran an 8 volt (tractor supply) battery in my 31 PA with no modifications since the day I first started her after the restoration. Never a fail to fire or any other problems. I do occasionally plug in an 8 volt battery minder, once a month for 24hrs for maintenance. All 6 volt systems operate perfect, horn, lights, etc. I prefer the peace of mind knowing I get a clean fire every time I hit the starter and she fires right up! I did notice on a recent trip to the $200 store or as my wife calls it, Costco here in AZ that they had a pallet of 8 volt batteries in the service area.

[SteveG]

Good to know you are successful with the 8volt system. Mine is doing good so far since I gave the battery a real good charge and the correct polarity.

SteveG

[Old Man]

OK one last kick at the can. An 8 volt battery is meant to be charged to 10.5 volts,may be 11.0. The internal impedance of these batteries are not reaching their maximum of several megohms because it never reaches a full charge. The electrolyte never reaches 1.250 specific gravity which would equal an internal resistance of several megohms. At this point current stops flowing,drops to a trickle, and the remaining current showing on the ammeter is the current being used by the car's buss (coil,lights,radio etc.) and that's of course coming from the generator. To reach this point with an 8 volt battery would require the reverse current cutout to be set to 10 or 11 volts. This would also then start the cut-out to cycle as it's supposed to. However this high of a voltage would blow all the lights etc. So I think that these 8 volt batteries are being undercharged and will sulphate themselves into a very short life. And I think since the cut-out never cycles ,as it never sees a battery in high impedance, the generator is in full on high current charge all the time and will see a very short life as it burns up. Just my opinion.