The Stovebolt Site Forums The Shop Area The Electrical Bay 6v Battery and charging

1953 3100 6v.

I recently bought a 6v 82Ah battery. It is only 82Ah because my distributer in Italy couldn't get more.

Question: Is that enough?

On initial start I had to crank a lot, and then had to do a bench recharge.

Now, I get about two starts out of it (I'm still not able to drive it on the road..just a garage start), run-up at idle, and then I have to remove it to recharge.

I've read the tech tips and have done what I can. I regret to inform that I also removed the negative with the engine running, and the engine did not stop.

Question: Does this mean my generator is charging ok?


Thanks,
Steven

Battery is small. Only way to measure the charging system is with a volt meter. Across the battery while it is running. About 7 volts would indicate it is charging. Might take a few minutes to recharge after starting. Lots of current pulled from a battery that small. There has to be some sort of Tractor battery available even in Italy I would think. Pulling the negative from the battery won't hurt anything. You just removed the load from the circuit.

You might consider putting two of those batteries in parallel if you can figure out some place to mount the second one. That will give you twice as much cranking amperage with the same 6 volts. Be sure the generator is producing 7.5 volts against a fully-charged battery after 20-30 minutes of running time at fast idle after starting. 6V batteries take a long time to recharge after starting, especially if you have to crank the engine for more than a few seconds.
Jerry

Yeahhh...if stuck with slightly too small a Battery...adding a second one would be really good.

If all is well with the Engine ( and properly tuned up and so on ) and with the Electrics and Charging Circuit...

The Engine should start very easily, even in cold weather...just a couple Turns and "Vah-Room!" it should start and be running...cold weather maybe four or five turns to start...even if the turns are 'sluggish'.

So, if it is not starting promptly/smartly, look to the details of the Timing, Plug gaps, Points condition and their Gap, Coil...Spark Plug Lead Wires, Valve clearances, Carburetor and Accelerator Pump, and so on.

I know my 6 Volt "216" 1946 Chevrolet Truck always started with just a flick of the Floor Starter Pedal in ordinary temperature ranges. ( I kept things in good order far as tune-ups and so on ).

A few times, 6 degrees above Zero, it was 'sluggish' and barely turned over at all! But it started on like the fourth or fifth turn...so...if all is well, there is no reason why a 6 Volt system would not perform just fine, and for the Engine to start smartly.

I'm not sure if that's an agreement with my suggestion, or a feeble attempt at sarcasm by someone with a woefully inadequate knowledge of Ohm's law. Either way, it's not worth an argument.
Jerry

Let me re-phrase then -


If one can only get a Battery which is a little too small for Cranking amps, then having TWO such Batteries wired in parallel, would be a good idea, since it WOULD provide the desired cranking amps or amp Hours.

I have no idea Jerry how you managed to take my mention so wrongly.

I was agreeing with you.

OK, no problem. Sometimes the meaning gets lost between the intent and the keyboard. Doubling the available current also has the advantage of less load on either battery which allows for more terminal voltage to make the coil work better. I've diagnosed several hard start situations caused by enough load on the battery to starve the ignition system for sufficient voltage. If our buddy in Italy has problems with battery cable size, and/or poor connections between the ignition switch and the coil and distributor, that could also be part of the starting problem.
Jerry

Yes indeed...

Poor/corroded/rusty/oily/frayed Chassis and Engine 'grounds' can contribute to the woes also of course.

With old vehicles, one pretty well needs to make a list, check it twice, and go through all those details, to make sure they are all in good condition.

Thanks guys.

I have a new wiring harness. I followed the instructions as best I could, and am sure that the wiring is correct. I put in new points and condenser, new plugs (gapped correctly).

What I didn't do:
1. As the plug wires seemed relatively new, I didn't change them.
2. I didn't remove the ground to battery to clean between the cable and chassis. (I'll do that now).
3. I think my battery cables are original. I will replace them.
4. I tried to measure the voltage at the battery at a high idle, but just after start...not after 20-30 minutes, and couldn't get over 6.5v.
5. I will try the two smaller battery solution if I can't find a larger 6v. Wow, the 6v here is expensive.....130 Euro. I really don't want to buy many of them.
6. I didn't rebuild or replace the generator and coil.

Question: About removing the neg from battery while running. Some say that this is a way to know if the generator is charging. Is there truth in this?

Thanks as always. You guys are a BIG help being stuck over here and trying to get the bundle of joy up and running.
Steven

If your old Cables are not corroded within the insulation covering, not frayed or having broken wires in them, they should be just fine...just make sure the ends are clean and free of Oxide layers...and that the Cables are the right Gauge for 6 Volt. ( Sometimes one can find lighter Gauge 12 Volt Cables someone had naively put on to an old 6 Volt system, so...)

You can clean and 'Tin' the non-Battery Post end of the Cables, also, if you want.

Might be a good idea to pull the Starter and the Generator.

Carefully dis-assemble them, inspect, clean, check their Commutators ( and reduce the height of the Mica if need be, and or have them Turned if need be as well ) and check their Brushes...make sure the Brushes move freely in the Brush holders and replace the Brushes if they are too worn down and not long enough to really have good Spring tension to work well any more.

Lube their Bearings well. If they have little Oil Cups on the ends, make sure those are clear and will flow alright.

Make sure the Springs which press down on the Brushes are still good, and still 'springy'.

This is all simple and forthright stuff, and fun and satisfying to do...helps you know your Vehicle, and to make it truely yours!

You can borrow a Reamer from a Mechanic probably, if you need to correct any deformation, or get past old Oxide layers, in the "Eye" of the Battery-ends of the old Cables.

You want to have nice bright clean Lead in there...no old Oxide layers.

Generator may need to be "Polarized" also, for your charging system to work right.


And, possibly, your Voltage Regulator may need to be adjusted, once you are sure the Generator is working well.

Steven,

If you replace both battery cables, be sure BOTH cables are at least 2 gauge. However, 1, 0 (1/0), or 00 (2/0) gauge cables are better but heavier. I use 2/0 (00) gauge cables.

If you cannot find heavier cables, try a welding supply shop and look for proper-sized copper lugs/ends.

Pulling one cable off while running is an old backyard test that the genny is working. If no output from the genny, then no volts at the points. But it won't tell you if the regulator is working properly. Just a quick and dirty check if the genny is working.

Ditto to all of the above. A 6V system simply won't tolerate a loose, dirty, or high resistance connection anywhere- - - -there just isn't enough voltage to push the current past the resistance. That's the primary reason manufacturers switched to 12 volt systems- - -they're more tolerant of less-than-perfect connections and smaller gauge wiring can be used.

When measuring terminal voltage at the battery posts it's vital to have a fully-charged battery. A low battery will give a false reading as the voltage will continue to rise as the battery comes up to full charge. If the terminal voltage is less than 7.5 volts with the specific gravity of the battery acid above 1.265, you need to SLIGHTLY increase the spring tension on the set of regulator points behind the "F" terminal under the regulator cover. A tiny change makes a big difference, so don't overdo it. Good luck, and keep us in the loop!
Jerry

Edit: Pulling a cable with the engine running is an old shade tree mechanic trick used by folks who don't understand how to check things using meters. A generator can tolerate the abuse, but NEVER EVER DO IT with an alternator equipped system. The resulting voltage spikes can destroy the diodes in the alternator, as well as any other solid-state devices in the electrical system. I have seen voltage spikes go to above 100V on an oscilloscope attached to the charging system when that's done.
Jerry