VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt Double up on batteries...?

I've always noticed that the 6-V battery I have in my '32 has sufficient power to crank over the motor, but in any subsequent stops where I have to re-start it no longer has any "uumph". My brother noticed the same problem with his 6-V battery on a '49 Indian cycle.

Is this just a common condition with 6-V systems, or a reflection of the limitations on 6-V batteries sold today? I thought about the possibility of tieing in another 6-V battery in the trunk for an extra boost while starting. Is that a reasonable idea, or foolhardy?

Yes, that is one way to go, and Yes 6v batterys have to put out double the volume of power (amps) to get the same wattage as a 12v battery remember:

Watts are a measure of volume of energy. (Volts) X (Amps) = watts. To get 1000 watts it takes (6)vdc X (166.67) amps, while at 12vdc it takes only (12vdc) X (83.33) amp to get 1000 watts, and it takes many watts to crank the engine fast enough to start it, plus furnish enough spark to fire. Also the generator takes longer to charge the battery back up since it charges at 6 vdc and is limited to 30 to 50 amps. ( a 53 Chevy charges at 35 amps)

Hey Ed! How many cold cranking amps is your 6 volt battery? By the way, the 943J generator that you have on your '32 should only put out a maximum of 18 amps cold and 15 hot. The ideal third brush setting is 12 amps at 1,700 RPM generator speed. :eek: :eek:

Your problem may be due to less than optimum ground. As the connections get hotter the resistance goes up lowering available power. Flooding from carburetor perculating is another possible cause. If everything is up to par starting hot is not a problem. My '31 fire truck cranks very well hot and cold. Well not too cold as it is not as cold here as the frozen north.

ChevyChip is right about the ground. Check your ground strap and make sure that there is no paint between it and the area in which it is bolted. Also, on your starter nose cone, make sure that there is bare metal on the nose cone and on the bell housing where the starter bolts up. The same is true for both battery posts. And, you should have at least a 600 to 650 cold cranking amp battery. One more thing, be sure that you are using a 6 volt positive battery cable and not a 12 volt positive battery cable. A 6 volt cable is a big mother compared to the 12 volt cable! :eek: :eek:

On battery cables, A good place to get the heavy gauge cables needed for 6vdc systems (00 is best) is at a tractor supply or a farm tractor parts store, these cables also have the heavy duty clamps that is needed.

Oh! that is also a good place to get a 6v battery and a new 6v - 12v charger.

Super! Great points, everybody. Well, I'll start with the checkups for bare steel in all the connections mentioned above.

Skipper, on two of your points:
- When you say "ideal third brush setting", do you mean that the third brush can be/should be tweaked? I changed the brushes during the rebuild, but I didn't think there was anything else to them.
- Cold cranking amps? *Sigh* I think that might be a contributing factor. I've scoured the auto parts store, and the best I've gotten is 450 CCA. Where could I find them 600 CCA babies?

ES

did you read my reply about the Farm tractor parts places (John Deere, I-H, Case, Massey Fergeson) and Tractor Supply Company? they have a selection of 6v batterys.

Hey Ed! Your '32 should have a 943J generator and the output is adjustable with a third brush regulation. There is a 10-32 slotted screw on the back of the end frame near the flippy top oiler, that you need to loosen. Then, with the cover band off, move the third brush (the one on the very top of the com.) towards you to increase the output or away from you to decrease the output. Then retighten the 10-32 slotted screw. The ideal setting is 3 and one half com. bars between the main brush and the third brush. At that setting you should have a maximum output of around 12 amps.

Interstate Battery sells either a 600 or a 650 CCA battery. Also, some of the jelly batteries are 850 to 1,000 CCA so you might want to check on those as well. The 450 CCA battery that you have is too small, and that could very well be part of your starting problem. :eek: :(

Great...thanks JYD. I'll poke around with the third brush and see if that helps.

Thanks, Mr. Mack - I realized what you were saying after I signed off. We don't have any tractor supply stores anywhere around here. They're way out in Central NY in real farmland. Well - that will be another good reason to visit an event hosted by the VCCA Finger Lakes region...!

OH! You mean that everyone in NY is not a farmer, like here in Texas, Well then who milks your cows, plows your garden, and does all the voteing? LOL

Here are some tips also Ed. Put some never seize on the areas of bare wire and metal. This will allow you to get a good ground without rusting the body. It will also protect the wiring from corrosion. Make sure that whatever battery you get that it fits in your battery box. I have to put a rubber pad over mine in my 46 because the previous owner installed a tall battery. If you go with a Gel Cell make sure it can be charged with a regular 6-volt car battery. Some Gel cells like Powersonic use a lower amp rating at charge. Also for Gel Cells, make sure you use a trickle charger. You can overcharge a Gel cell battery and kill it. It will develop a memory and never charge above that memory. The company I used to work for used Gel cells everyday. They are really great with no mess but you should invest in a good trickle charger for them. Ac Delco also makes a great 6 volt battery for tractors. We use these on our tractors since I'm also into restoring antique John Deere's. Try O'Reilly auto parts or CarQuest.

Here's a place where you can order good, heavey duty "00" wire cables for your 6 volt Chevy. They look great and he'll make 'em any length (and color) that you want.

• Arbee Distributors
• Ron - in Seattle, WA
• 206-365-3615

Another idea, if I'm not mistaken all positive cables for early thirty's cars should be colored black. If you buy 'em in a store, they're usually red... so... don't! ha!

Mudbug - Hey - super ideas! I do have a trickle charger, and it gets me going the first time around. Apart from that, I can use all of your suggestions, as well as the otheres above. And when I go out into farm country I'll stop in the parts store for one of those big ol' 6V tractor batteries. I'll wear my jeans and a Case ballcap so they don't think I'm lost...

ES

Glad to make some suggestions for ya!!

Thank You members for all your sugestions; all of them are a big help in solving this 6 volt problem -----------TOM P.