6 volt battery jumping

[Guest JDHolmes]

I need to use a 12v battery to start/jump start my Chieftain. It's been sitting so long (over five years) that the 6v just won't hold a charge long enough to turn the car over enough to start it.

I've tried priming with starting fluid and I can only get about four good attempts with the 6v battery before it needs to be recharged.

Any suggestions? Has anyone used 12v to start/jump the 6v system. I understand that the 12v will cause starter to overheat faster and I need to be careful about that but any other suggestions are needed and appreciated.

[Jay Wolf]

I make no claims as to this being correct but the way I always do it is:

Turn everything off lights, heater etc.

I do not connect the 12 volt till the 6 Volt engine in cranking

and I disconnect it as soon as it starts so 12 volts never go through the 6v accessories of the 6 volt car.

I use a jumper pack with an on/off switch so it is easy, if you use cables it is a little harder.

[Guest imported_JPIndusi]

Since you are not in an emergency situation, I would go buy an InterState Battery from AID or another such auto store. I think that car uses the long thin 6 volt Type 2E battery which is still sold at local parts stores because it may have an application for a tractor or other commercial use. Jumping with 12 volts should only be done a last resort for an emergency.

Joe

[Guest JDHolmes]

Thanks. I've got the Interstate battery. It's very new and has only been used in this car. The problem is the drain down is significant trying to crank this beast. Battery is good. I've checked it with hydrometer/hygrometer (always get it mixed up) and is at 6.7 volts. Motor is free.

[Bob Kinker]

If the battery is as good as you think, I would check out that starter. Sounds as if it may be on it's way out! Just food for thought.

Bob

[Guest chieflander]

I have the same problem on my '51 Chieftain. I finally had to take the battery from the '48 Chrysler NY. It was interesting because the battery is an odd shape on the Chieftain! It started that way. But I can only get 3 or 4 cranks on the battery that goes in it. It's only 2 months old, so the battery is good. I suppose it could be the Gen or Starter. I also changed the fuel pump, and can't get it to pump with either battery!!

[dlh61olds]

This sounds like the usual ground problem. Make sure the starter attaching bolts are tight as well as all connections on the hot side.

Check engine timing as well.

Make sure all ground connections are tight and that there is a ground strap from the engine to the frame. The ground side is most likely the culprit.

Good luck with your project, Dave

[1913Moline]

On a hot day, with my kids in the back seat of my newly rebuilt 29 Pierce- stopped the car and it wouldnt re-start (it had less than 50 miles on it and was pretty tight at first). I knew better, but decided to jump the car with 12V. Battery is just below your legs under floor mat. Wouldnt crank at first, so I reached down to shift the cable on the 6V terminals.

Blew the top off the battery, blew acid all over my legs and the interior of the car. Sounded exactly like a 12 ga shotgun was fired inside the car. The top of the battery blew off and cut my leg.

Once you have a battery blow up all over you, you will be incredibly careful. I wrote up an article on my stupidity in the local Pierce club publication.

All I can say is you dont want to do what I did.

Now the $100 price for an Optima doesnt bug me as much. I will never drop a wet cell battery into another of my old cars.

Put 2 6V optimas in parallel and you will start your car or melt your starter, but you wont be lacking amps.

Greg

[Guest JDHolmes]

Thanks for all the input! Is there a ground strap from the frame to the motor? Other than the battery ground cable?

New starter. New battery. New ignition parts and pieces. Freshly rebuilt carb.

Where can I get/order Optima 6v batteries? Local interstate didn't have them. I will take the advice here though, and will not attempt to jump the car with 12v. I certainly don't want a bad experience as those mentioned here.

[Ron Green]

Give the battery a good charge, connect a quality digital volt meter, disconnect the coil wire and have someone crank the engine. It the meter shows under 4 volts when cranking then the starter needs attention as it is drawing too much. Also check all the cable connections for tightness and cleanliest. Verify that the battery cable sizes are the correct size.

[mrpushbutton]

What dlh61olds was saying (if I may attempt to translate/amplify) is to make certain that there is a BRAIDED GROUND STRAP on the appropriate terminal of the battery, and NOT a pep/sears/zone generic 12V battery cable. 12V systems use less current (more voltage/less current) ergo a smaller diameter cable. 6V systems thrive on current, which demands a large area conductor. Sorta like: pouring soda out of the traditional coke bottle vs. dumping it out of an open glass. Starting the car is like dumping out all the soda at once. Many an old car has had the original cables replaced with off the shelf 12V cables. They are a bottleneck to the flow of current. Braided cables contain a HUGE amount of surface area (many small diameter wires braided together)Go with the optima battries--they pack the cold cranking amps your starter wants. Don't use starting fluid. Get a plastic squeeze bottle with a tapered tip--like the ketchup containers in hot dog joints. Fill a (clean) squeeze bottle with gas and fill the carb. bowl from the bowl vent (usually a brass tube protruding into the air horn at a diagonal angle) feed until the tube "spits up", indicating it's full. Set the choke and start the engine. That bowl full of gas should be enough to run the engine for 30-45 seconds, enough for the fuel system to prime itself. If it takes more than two tries like this to keep the enginge running, start looking at your fuel pump or carb inlet valve.

[Guest JDHolmes]

Thanks. I do have a standard 2 ga. battery cable on the negative side. I have a 1ga. on the positive side. I will replace the ground side with the braided.

Per suggestion, I checked the voltage on starting without the coil...5.5 amps still on the battery, well above the 4v mentioned. Rechecked the battery and all cells are fully charged.

I did, however, check my manual which shows a ground from motor to frame. But, there doesn't appear to be one other than the battery ground cable. As per the diagram, this is a solo, specific cable.

On the way now for the braided strap. Thanks again for all your help.