Rob, I'm not a fan of the 12/6 batteries. And they don't look original. How about converting to 12v, then getting one of the 12v alternators that look like a generator? This way you get all the bennies of going to 12v . . . brighter lights, the ability to buy bulbs anywhere, ability to add modern accessories such as a hidden radio, cruise control, and A/C if you ever want to.

Park,

Thank you for your comments.

If I may ask; why do you not like them?
I can understand the part about not looking original, but then a 12 volt battery doesn't look original either.

Isn't the conversion (to be able to use a 12/6) simply adding an alternator and the new battery and running the cars original 6 volt system off half the 12 volt battery, and using the 12 volt capacity to run the modern accessories?
I may be missing something, but wouldn't this bypass all the issues and expense of replacing bulbs, adding resistors, changing horns, starters, etc.?
Using "one half" the battery more than the other may shorten its life a bit, but that would be pretty minor if you replace batteries every 4-5 years anyway for reliabilities sake, no?

Rob

First, my feeling is that if you don't plan on putting A/C in it and don't have any other reasons except an idea that 12v is better, why change any part of the system to 12v? For a 12v radio, just get an appropriate 6 to 12 inverter gadget and run the radio off of that.

As to your Q on my dislike of the 12/6 batteries, I just think it's needless complication and there are better solutions. It's really not that difficult changing to all 12v. Only a couple of places needing resistors. And a starter needing conversion, especially if it's a Hydramatic car. And why continue running anything on 6v? What's changing out a few bulbs in terms of either cost or time? The 6v devices draw almost twice the current of their 12v counterparts, putting more load on the generator or alternator and making those (6v) circuits more sensitive to corrosion, etc..

I am curious about air conditioning. Why does one need 12 volts instead of 6 volts?

Park,

Thank you for the clarification.

As I stated in my original post, adding air conditioning is the number one reason, along with a radio and charging outlets for electronic devices.
I'm not of the opinion that 12 volts is "better" I'm fine with 6 volts, it has always worked well for me as long as all the connections are clean.

My thoughts were that if the existing 6 volt system is okay and working fine, I could leave it as is.
The 12/6 would continue to run the 6 volt system with the only change being the alternator.
The 12 volt side of the system would run the air conditioning and other desired accessories.

The 6v devices draw almost twice the current of their 12v counterparts, putting more load on the generator or alternator and making those (6v) circuits more sensitive to corrosion, etc..

So in general, if someone is considering a conversion, you advocate doing away with the 6 volt system for these specific reasons?
If so, then converting everything to 12 volts would seem to make more sense.

I've read about the starter conversion on your conversion data sheet, I'll study it further.
Thanks for my continuing education.

Rob

Per, there's nothing inherently wrong with a 6v A/C unit if you can find one. Except that it's just another high current-draw device being added to an inefficient 6v system. And 6v units are getting pretty rare.

Rob, I think I've said enough about 12 v. 6. Anyone who has a different view is certainly welcome to it. I merely offer my take on the way to convert to 12v for anyone who wants to make the change. My suggestions are based on working with automotive and aircraft electrical systems since the fifties, and an EE degree from U of Ill to help understand the scientific aspects. Needless to say, there are other opinions out there.

Park,

My apologies if I came across as challenging your expertise. It was not my intent to do so.

I'm just trying to learn and understand about that alternate system.

I appreciate all the help you've offered on, and off line and have no wish to offend you.

Rob

Not to worry, Rob . . . no offense taken. This subject is one of those that have multiple solutions. I've merely been explaining how I look at it, which is a more conservative approach than some folks choose. For example, a fair number of Hudson owners are running 6v overdrive systems on 12v and have had no problems. I prefer to make the changes needed so the unit is experiencing the voltage it was designed for, to minimize the chance of a failure on the road somewhere.

For what it's worth, I have a Hudson friend with a '54 coupe, original 6-volt, with a modern 12 volt air conditioner added. He did something to the compressor (I think), loosened or tightened the spring (in the relay or solenoid switch?) which allowed 6 volts to operate that solenoid or relay. Sorry I can't be more specific, but the thing works on 6 volts!

As to converting 6 to 12 volts for accessories, I thought there was some sort of converter or transformer or rectifier or something, which would do that? If only for "small" accessories?

Jon, I think "inverter" is the proper term for a "lower to higher" voltage changing unit, but the commonly used term seems to be "converter". Anyway, whatever it's called, it's an electronic box that does the job. In planning, one should take the current draw of the 12v equipment, multiply by 12 to get the wattage, then double that figure (for safety margin) to see what the wattage capability of the inverter/converter needs to be. They're available in a wide range of power (wattage) capacity. Sometimes the 12v equipment will have the wattage figure on the data plate, etc., but often it lists only the current draw (amperes), so you have to calculate the wattage.

Jon,

Thanks.

I'm not experienced enough with air conditioners to start making modifications like that, though there are some very brilliant people out there...

The accessories I was referring to were 12 volt outlets/cigar plugs, for such operations as cell phone charging.
An inverter, as you were thinking, would give you 120 volts for household plug in items.

Rob

Rob, Don't forget all the differences between AC & DC systems. To get 120 volts AC out of your car is very different than 12 v DC

FYI
I go 12v on everything. The Instruments reduce down to 6V with an Itermittent regulator (IVR). Just change the bulbs and install a GM Alternator with an Internal regulator then discard the 6V regulator.If you dont crank the starter long it holds up fine for me at least.. If worry get the Starter Field Coils changed to 12V.

Rob, Don't forget all the differences between AC & DC systems. To get 120 volts AC out of your car is very different than 12 v DC

David,

Thank you for your thoughts.

I'm not planning to install an inverter to produce 120 volts, I was just commenting on the inverter Jon mentioned.
All I'm planning on is a couple 12 volt cigar plugs to charge a cell phone, etc.

Rob