Talking about one of my long mental side trips...

[James_Douglas]

After following the Delco recommendations, and finding out that my car has a total vehicle electrical load requirement of approximately 75 AMPS…I have decided to convert to 12 Volts.

Delco recommends that the alternator output should be 50% greater than the load requirement.

I checked with several vendors and apparently the MAX amperage you can get in the 10SI series alternator in 6 volt positive ground is 53 AMPS.

So, no matter what I do, if I am driving on a rainy night and have everything going, I will not have enough alternator output to keep from draining the battery. On a long x-country trip, this will be an issue.

So, I need to start doing some planning. Radio needs to be re-built for 12 volts; the wipes and fans need step-down transformers or resisters, the coil needs changing as well as the starter. The starter will be a problem as the Desoto uses a special solenoid and I do not know if it can handle the extra voltage.

Oh fun fun fun…James

[TodFitch]

I should probably keep my mouth shut. (Keyboard silent?)

If I recall correctly, all the accessories and lighting you have is basically factory stock. So it seems to me that the original factory electrical system should probably be able to support the load.

You installed an Optima battery because it was "better" than the original.

However the charging characteristics of the Optima when used with a generator and mechanical regulator on a daily basis caused problems with generator.

So you went to a 6v alternator.

And now you don't have sufficient power for all the accessories, at least at idle. Hmmmm. How come they can't run off the battery when at idle just like they used to do with the original battery and generator? Isn't the Optima up to the task?

Anyhow you are now considering converting to 12v which will entail further effort especially with regards to the radio.

How about revisiting the original change: What is so good about the Optima battery that it makes all the other travails worth the effort?

[Don Coatney]

After following the Delco recommendations, and finding out that my car has a total vehicle electrical load requirement of approximately 75 AMPS…I have decided to convert to 12 Volts.

Delco recommends that the alternator output should be 50% greater than the load requirement.

I checked with several vendors and apparently the MAX amperage you can get in the 10SI series alternator in 6 volt positive ground is 53 AMPS.

So, no matter what I do, if I am driving on a rainy night and have everything going, I will not have enough alternator output to keep from draining the battery. On a long x-country trip, this will be an issue.

So, I need to start doing some planning. Radio needs to be re-built for 12 volts; the wipes and fans need step-down transformers or resisters, the coil needs changing as well as the starter. The starter will be a problem as the Desoto uses a special solenoid and I do not know if it can handle the extra voltage.

Oh fun fun fun…James

James;

Tod mentioned everything except your radiator cooling fan. Exactly how many nights do you plan on driving in the rain with an over heating engine playing the radio (full blast) with the heater/defroster running on high sitting at a stoplight with the brake light and turn signal on, cigar lighter pushed in just waiting to light the next stogie, honking the horn at the baseball bat weilding butt hole who pauses at the stopight in front of you because you stopped too close to his rear bumper:D

I always thought the fun of driving a 50+year old car was the challange of beating the odds. Seems you want to remove all the fun.

[James_Douglas]

Tod,

I do appreciate the point you are making. I do think that battery is beside the point.

What I am really after is the ability to sit at idle on a rainy night at a traffic light with the wipers, headlights, radio, brake lights on, the twin heaters on high and being able to see the dash and know that a car behind me will see the brake/tail lights and not slam into me.

Based on the calculations and the recommended procedure by Delco for generator/alternator sizing I have concluded that the original generator and the alternator I am using are both below the recommended threshold.

That is why I have concluded that I need to make the change.

When everyone was driving slower and the candle power was less driving the car as designed was not a problem. But, I use mine a lot and a night a lot and in the rain a lot. Coupled with that I do it in some of the most intense driving areas in the world as you well know as you drive in it too.

I am also looking at Sondra and I making a three week trip to the south west in September. Being able to use our laptop for navigation and to be able to charge our cell phones would be an added plus.

I just talked to a guy who can re-wind the power transformer on the radio for 12 volt. That plus a 4 post 12v vibrator and a set of tubes and I am back in business radio wise with having to gut the thing and go solid state.

I think the optima thing is just related to some mechanical regulators as my flying magazine article showed. The other issues I think are wiring things like oxidized terminals and the like.

All that said, I REALLY do appreciate your point and I have pondered it over the last few days. But in the end , I think the switch to 12 volt will have more good points than bad. If I was not going to use the car as extensively as I plan to then I would not make the change.

Best, James

[James_Douglas]

Ok Don, What voltage is your car running....

[Normspeed]

Tod, from what I've read about Optimas, they actually carry a lower voltage at full charge than lead/acid batteries. Something around 11 to 11.5 volts in the 12 volt models. No advantage there. (A lead/acid 12 volt is well over 12 at full charge.) I think the big advantage in Optimas is the sealed construction, although spillage has never been a problem for me with a stock lead/acid batt.

I'm not against upgrading our old Mopars but it seems like a lot of the folks are beating themselves up replacing original type systems that worked well for a lot of cars over a lot of years. JMHO. I start mine, it starts instantly. It charges. My headlights are bright enough for safe driving. Even short trips several days apart will keep the 6V +ground setup well charged. I just don't see the advantage to the upgrade.

Edit: James, I'm sure your rig has the ability to draw more amperage than a Plymouth due to more and bigger accessories, dual heaters etc. but the 46-54 Plymouth manual lists only three generator/regulator setups, at 35, 40 and 45 amps. Seems like your present alternator should be able to do the job.

[Don Coatney]

Ok Don, What voltage is your car running....

James;

I am running 12 volts but my car was half fast converted when I bought it. However the 12 volt conversion has not added much driving ability to my car. I do not even have a radio in my car but I do run with my 12 volt GPS. My battery stays charged. Does yours?

[James_Douglas]

James;

I am running 12 volts but my car was half fast converted when I bought it. However the 12 volt conversion has not added much driving ability to my car. I do not even have a radio in my car but I do run with my 12 volt GPS. My battery stays charged. Does yours?

So far it does...But at night it is har to see the lights with the heat on....

[Norm's Coupe]

I'm still running with the old original 6 volt system in my coupe. Have a level 1 lead acid battery to boot. That's what the battery shop said I needed. Granted I do not use the headlights much. However, when I do they are nice and bright and I can see well. I can also see the dash lights with the heater on or off and the brake lights on. I've added two extra stop and turn 6 volt led lights in the rear also. Still have nice bright lights all the way around, day or night. Don't play the radio, in fact I took it out because it didn't work and I wouldn't listen to it anyway. Wipers are not a problem with the electric because they are the original vacuum wipers. Regardless if the car sits for a week or just overnight, it starts right up on the first try. In fact, many times it does not even do a complete turn over before it starts.

Now, of course I don't drive the coupe every day and don't plan to. However, while stationed at Granite City Army Depot, Granite City, IL back in 1963 I had a 52 Dodge. Never had a problem with lights on it either, even with heat and electric wipers going. I put about 25,000 to 30,000 miles on that car in about 6 months with driving it back and forth to Louisville, KY every other weekend, plus running around southern Illinois and MO. One weekend the battery was dead when I was getting ready to go home for the weekend to Louisville. Had a guy give me a push to get started, then drove all the way to Louisville (about 300 miles), in the dark and in the rain with a dead battery running off the generator only. Lights were nice and bright and the wipers worked. Even had the radio playing most of the trip. About half way home stopped to eat. Me and another guy riding with me pushed the car, started it and kept on going after eating. Did not hurt anything doing that either. Simply bought a new battery in Louisville the next day and was good to go again. It's hard to kill these old Mopars with their old electrical systems.

So, if your electrical system is up to snuff everything should be working properly.