Electrical: 6 volt batteries in series?

[Lothar]

I want to have a modern stereo in my car, but I would like to avoid the hassle and expense of converting the entire car over to 12 volt. There is plenty of room to set up another battery on the passenger side of the engine compartment. Could I just hook the batteries up in series to the stereo (to produce 12 volts) but have them hooked in parallel to the generator?
I'm no electrical engineer, so I'm not sure about how this would be set up, but it seems doable in theory. Has anyone else done this or seen it done?


1950 Champion 4 Dr.
Holdrege NE

[whacker]

If you want to have a modern sound system, I think you would be better off converting to 12V Negative ground, and be done with it. Your 6V car is positive ground. There are several guides around that describe how to do it, and you can run any modern electronics with it.

[gordr]

You cannot connect batteries both in series and in parallel at the same time. That's what's known as a short circuit. Much smoke and fancy footwork will ensue.

Either do as whacker suggests, or go with a voltage inverter that will accept a six volt positive ground input, and output 12 volts, either negative ground or floating ground. If the inverter incorporates a transformer, and is wired properly, the 6 volt side is isolated from the 12 volts side, and either leg of the 12 volt output could be grounded, as long as the "hot" terminal of the 12 volt side is not connected to the "hot" side of the car's six volt system.

Jeff Hopman (Jeff_H on this forum) has built an inverter for this purpose to use in his car, and electronics is his real-life job, so you know that it was built to last.

Try using the search function on this forum to search "inverter" posts authored by Jeff_H.

Gord Richmond, within Weasel range of the Alberta Badlands

[alanmende]

Lothar,

There are two ways of doing it. One is to have your 6-volt radio converted to AM/FM/stereo. It can still be operated on 6 volts as long as you let the shop know what you want and they put in a 12/6 volt inverter in. I had our radio converted that way by Mike Hagen of Fairless Hills, PA (sorry, no web site that I know of, but you can find him in the Hershey flea market in October). It cost in the neighborhood of $300; that might be too rich for your blood. So the second way is to use a 12 volt motorcycle battery to power just the 12-volt radio. It should have enough juice in it for you to play the radio for a day. Then you can just recharge it with a 12-volt charger. I've seen this done so drivers of 6-volt cars can use a CB radio on road trips.

Kindest regards,

Alan Mende
Hummelstown, PA

I'm not a mechanic; I don't even play one on TV.

[warrlaw1]

I'm thinking of the same problem with my 55 K code. I want the stock radio and am keeping it 6V. I like the motorcycle battery idea and was also thinking of just getting a portable blaster to supply the tunes from the back seat. Then I thought about Ipods and MP3 players with a line out feature. I don't want gangster sounds, just traveling tunes. Think I could line out an Ipod or similar device to the 6V radio? Stereo is great but at 60 mph who can distinguish? The radio in my old Acura has a line level input. Couldn't I do the same with the Stude?

[countryboy]

quote:Originally posted by alanmende

Lothar,

There are two ways of doing it. One is to have your 6-volt radio converted to AM/FM/stereo. It can still be operated on 6 volts as long as you let the shop know what you want and they put in a 12/6 volt inverter in. I had our radio converted that way by Mike Hagen of Fairless Hills, PA (sorry, no web site that I know of, but you can find him in the Hershey flea market in October). It cost in the neighborhood of $300; that might be too rich for your blood. So the second way is to use a 12 volt motorcycle battery to power just the 12-volt radio. It should have enough juice in it for you to play the radio for a day. Then you can just recharge it with a 12-volt charger. I've seen this done so drivers of 6-volt cars can use a CB radio on road trips.

Kindest regards,

Alan Mende
Hummelstown, PA

I'm not a mechanic; I don't even play one on TV.

I agree 100%

That's what I did with my 50 Champion, and 50 Commander, except I used a lawn mower battery. I put the battery between the spare tire and the passenger side of the wheel well, and ran the wire over the headliner while the car was undergoing restoration, however the wire can be ran underneath the car to the terminal board. I have an 8 track tape player in both of my Studebakers, and run the things at car shows to liven things up and I have a terminal board mounted up under the dash where I can add additional 12 volt gizmos to the gambit. Thinking of putting an ARC 45 rpm record player in the car along with a reverb unit. The battery holds up all day with a nice charge level and I recharge it with a BATTERY TENDER PLUS Charging system overnight. http://www.batterytender.com/ I have a 6 volt and a 12 volt charging system that keeps things ticking.

[Lothar]

Gord and others:
Thanks for setting me straight and pointing me in the right (non-flammable) direction. The 12 v lawnmower or motorcycle battery seems like the simple solution. Thanks, guys.

1950 Champion 4 Dr.
Holdrege NE

[studegary]

I have used a commercially purchased invertor/converter to change the six volt positive ground to 12 volt negative ground. I mounted the small unit up behind the dash.

Gary L.
Wappinger, NY

SDC member since 1968
Studebaker enthusiast much longer

[CHAMP]

I have a heavy duty lawn mower battery ( 375 C.C.A. ) in mine. I also use a solar powered battery charger that I got from J.C Whitney. As for the memory I use an inverter.

GARY H 2DR.SEDAN 48 STUDEBAKER CHAMPION NORTHEAST MD.

[Lothar]

Okay, you all said it couldn't be done, and it still might not make sense, but I found the following statement in a discussion about 6 to 12 volt converters.

"Larry Klein (Audio columnist for Electronics Now, formerly of
Stereo Review) told of how he put a 12volt stereo in his 6 volt
Volkswagen. This was years ago, so it might not work with digital
stereos.

He bought a 6 volt motorcycle battery and a double-pole-double-throw
(DPDT) switch. He wired the switch so that in one position the
motorcycle battery was in series with the VW's battery and that
supplied the 12 volts for the radio. In the other position, the
motor cycle battery was put in parallel with the car battery.
After shutting off the radio and car, he would put the switch
in this second position to let the car battery recharge the
cycle battery when the car was parked."


Neat huh? Can any electronics experts confirm that this system would work?




1950 Champion 4 Dr.
Holdrege NE

[warrlaw1]

You want to charge a motorcycle battery from you car generator? I guess you can step it down, but I wouldn't want to do it by trial and error. Most RV's and Marine uses have a dual battery system with the double throw switch: one to run the accessories and one to start the engine if all else fails. They're not contemplating different amperages and reversing the grounds. Sounds like more trouble than it's worth. The motorcycle battery would be the first to explode.

[PackardV8]

Theoretically [u]could</u> and practically [u]should</u> are two different worlds.

Yes, it is theoretically possible, with the correct system of manual switches and/or diodes to run two batteries and a 6v negative ground main and 12v positive ground auxiliary system in the same car.

No, in the real world, too much can go wrong and burn down the car, destroy the electronics, explode acid on you and the nice stuff, to be worth the risk.

thnx, jack vines



PackardV8

[Lothar]

Ok, guys, I'm convinced that this two battery, parallel/series connection setup isn't the way to go. I just liked the elegant simplicity and the self-contained aspect of it-not having to charge the battery with a charger, and not having to buy a 6v to 12 v converter.
I know that the second 12 volt battery system of powering the stereo is widely used, but has anyone in this group used a 6v to 12v converter to power a stereo? As I understand it, they are available commercially from JC Whitney and others, as well as do-it-yourself kits. Do they work ok and provide adequate power?

1950 Champion 4 Dr.
Holdrege NE

[gordr]

quote:Originally posted by Lothar

Ok, guys, I'm convinced that this two battery, parallel/series connection setup isn't the way to go. I just liked the elegant simplicity and the self-contained aspect of it-not having to charge the battery with a charger, and not having to buy a 6v to 12 v converter.
I know that the second 12 volt battery system of powering the stereo is widely used, but has anyone in this group used a 6v to 12v converter to power a stereo? As I understand it, they are available commercially from JC Whitney and others, as well as do-it-yourself kits. Do they work ok and provide adequate power?

1950 Champion 4 Dr.
Holdrege NE

Lothar, I've never used the converter from JC Whitney. It would probably be adequate for a regular AM-FM radio/CD/Cassette (do they even sell cassette stereos anymore?), but would not be able to power big amps and sub-woofers.

You might hear a little whine in the speakers from the switcher in the converter. Make sure the converter you buy is OK for positive-ground cars. If that is not available, you ought to be able to use a negative-ground converter, as long as both it and the radio are isolated from the car body. That would also mean cutting the shield braid near the plug on the radio end, and pushing it back so the shield braid no longer makes contact with the shell of the plug.

If the inverter you choose has its output internally isolated from its input, it would not be necessary to isolate the radio. It all depends upon the inverter chosen.

I built my own inverter once that used two power transistors, and a small transformer with two equal-sized center-tapped windings. Basically, it developed 6 volts pulsating DC across each winding, and the windings were stacked in series (DC-wise) to give 12 volts. This unit HAD to be isolated from the car's body ('54 Champion) as it had no internal isolation. One nice feature it had (quite by accident) was that it started automatically when the tape player it powered was turned on, and it's no-load current draw was negligible. I've since lost the circuit diagram for it.

If you decide to go for an auxiliary battery, look at getting a 12-volt gel-cell (AGM) battery, such as are used in emergency lighting units and computer UPS units. They won't spill acid, and are quite compact. One of those, and a small solar panel to charge it, ought to work just fine, unless you plan on constant use of the radio.

Gord Richmond, within Weasel range of the Alberta Badlands

[Lothar]

Gord
Thanks for your ideas. I really like the gel cell battery/solar cell rig. Now I just need to figure out where and how I can unobtrusively mount a small solar panel. Maybe I should install a sun roof? My Champion might become the first internal combustion/solar-electric hybrid Studebaker!

1950 Champion 4 Dr.
Holdrege NE