12 conversion

Reading half the real current is fine by me. In some circles, folks say a voltmeter is better for seeing the condition of the charging system anyway.
 
With this model of charger, the alligator clips can be removed and the ring lugs connected to the battery. Then the polarized plug at the other end can be routed to the engine compartment for easy access. Found at https://www.batterytender.com/Battery-Tender-6V-12V-1.25A-Selectable-Battery-Charger They have other 6v chargers.

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another two cents worth.... 6v batterys are getting hard to find , expensive, and from my own experience and what i hear around the grape vine, they ain't very good quality any more... short life span. i try to convert everything i have to 12v bulbs etc are more readily available. i don't like the external ballast resistor, you can get a 12 v coil with built in resistor (don't know the # right now) the problem is the pimple faced kid in the auto parts can't find anything that's not in the computer, you have got to find a guy that will do a little digging.
 
larry harding said:
another two cents worth.... 6v batterys are getting hard to find , expensive, and from my own experience and what i hear around the grape vine, they ain't very good quality any more... short life span. i try to convert everything i have to 12v bulbs etc are more readily available. i don't like the external ballast resistor, you can get a 12 v coil with built in resistor (don't know the # right now) the problem is the pimple faced kid in the auto parts can't find anything that's not in the computer, you have got to find a guy that will do a little digging.
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Standard Motor Products UC15T , can be purchased on Amazon if you like.
12 volt with internal resistor .
 
Coils, by their name, already are a resistor of sorts in relation to the primary winding. The 3-Ohm primary type coils are made to work on 12-volts. The 1.3 to 1.5 Ohm ballast resistor or resistance wire is only necessary on a 1.5 Ohm coil being operated on 12-volts. Manufacturers were slow to go to the 3-Ohm coil. The 1.5 was used clear up into the late 60s & early 70s. Electronic ignition systems finally made the manufacturers change.

External ballasts kept the heat on the outside of the old coils. Many had an oil insulator inside that could leak under extreme conditions. Modern coils use a high temp type epoxy resin inside that can take the heat.
 
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The car started just fine in 1929/31 using low octane fuel. and batteries that were probably not as good as what we have now. I show my 1914 Cadillac at the national meet, it starts great on 6 volts on the coldest days in Oklahoma. Spend some time cleaning Conections, scraping paint from the flywheel housing where the starter mounts, and learn how to use an Ohm meter to check for resistance
 
As posted above, 6 v batteries are harder to find, more expensive, poorer quality, shorter lived, worrisome for some to jump start, etc. in my opinion, at this time, and in my place. Your Mileage May Vary as some say.
When a child, we played "musical chairs", one less chair then the number of players. My wife says i play "musical batteries". The nice cars sit out the salt season. Their batteries age, (despite battery tenders, trickle chargers, and in boat yards, a heated shelf with all the batteries hooked to on central charger). I find it easier to have all the tractors, wood splitters, modern cars, beaters, English cars, and the model A to have the same 12v and neg ground. I have changed batteries since my teenage years to fit the occasion. One, or only a few, commonly found, simply available, Group 25 12v can fit all of the above, with regular use is always pretty well charged, COSTS LESS (important to me), etc. Musical batteries plays much easier if all the players use the same battery.
Side note:"Musical License Plates", if played appropriately and safely, works too. I've seen several Model A's with the same serial number stamped on the frame ,right inside the edge of the floorboard. Before I'd pass one of these on to a new owner, of course, I'd wipe that out. A correct number is ,very likely, hidden under the body, if inquiring minds really must know. YMMV.
Nothing else to see or say here, let's move along,
Russ
 
To change the starter over to 12 volts, rewire or replace the field windings. See https://www.snydersantiqueauto.com/product.htm?pid=976153.

You will need a good soldering iron. I have found the Weller brand, the kind with the trigger, works the best.

The 6 volt windings are two in parallel and 2 in series. The 12 volt winds are all in series.

The screws that hold the magnet poles in place can be removed by using two large C clamps to clamp the poles to the case and take the pressure off the screws. The same procedure is used to put the screws back in.
 
nkaminar said:
To change the starter over to 12 volts, rewire or replace the field windings. See https://www.snydersantiqueauto.com/product.htm?pid=976153.
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Those are the field windings I said failed (in post #15). They were the wrong shape and soon shorted to the body of the starter. IMO, they were poorly made so I now use originals. They have worked for well over 90 years and continue to do so.
In addition, a set of those would cost close to $100 here. My conversion costs me nothing but a little time (and some wire and solder)
 
If 6 volt batteries ever become unavailable, I might consider changing over, but even in my small city, there are several places to get them.

6 volt cars crank slower than what we are used to in our modern cars, but I have never had it not start. The exception was when I left my lights on and drained the battery, which would also happen with 12 volts. I am perfectly good with leaving something that has worked reliably for 94 years in place.

For charging, rather than pulling the floor board, just lift the hood and connect the positive (red) charger cable to something grounded such as a head nut, and connect the negative (black) cable to the nut on top of the starter where the cable connects that comes directly from the battery. Very easy.


So, I am leaving well enough alone.
 
Can anyone suggest a 12 volt battery for a 30 model A. Les Andrews says to use a group 25 675 cold cranking amps. The only problem is they only make up to a 550 cca batteries the group 25 that will fit. Any suggestions?
 
To add my 2 cents worth for 6volt. My A's have worked fine for 90 years on 6 volts and it has already been said that if everything is set up properly it will continue to do so. As far as a battery maintainer, I have a pigtail run up beside the starter that I plug in whenever they will sit for a while. I also have a safety fuse at the starter that protects the car. It has been suggested to me that when they sit for a while to pull the fuse, so when I raise the hood to plug/ unplug the maintainer, I also plug/unplug the fuse. As Bighammer mentioned, I have had my A start on 6volts when my newer ones wouldn't.
 
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