The Stovebolt Site Forums The Shop Area The Electrical Bay Never Enough Juice to Go

Let me begin with my ranting, this is the second stovebolt I have restored, this one being a 49, 216 model 3100 panel truck with a stock 6VDC generator system. The common and most concerting problem I had with both vehicles is dead or near dead batteries with hardy enough power to start, if they did start. To answer your question; the truck has a stock 6VDC system, new high amp circular cell battery, new battery cables, clean and tight electrical connections, a rebuilt generator, starter, and regulator. To answer your second question, to the best of my knowledge there is nothing draining the system while shut down. SO WHY is the battery always dead or near dead. I charged it for two days after failing to start the last time and the only thing it did was grunt and would not start. I just finished a full body off restoration and insured it but I dread taking it out for fear of it not starting again for me. Please, what the heck is the problem with these 6 volt system that one can’t rely on them to get the engine going? Please, and any all help is greatly appreciated.

God bless,

Dave

What are the load test numbers on your battery? "New" doesn't necessarily mean "good". Unless you can load the battery down to 1/2 its cold cranking amp rating for 15 seconds, and the voltage stays above 4.5 volts with the load still on, you haven't tested it yet.
Jerry

Dave,

If your battery is draining while sitting for short periods, that sound like you have a short somewhere. Have you checked for shorts (and, how)?

What size battery cables?

Are your ground cables bolted to clean metal (no paint)? This might not be the trouble, but it is worth checking when someone says they have just done a body off restoration. I use a anti-oxidant conductive copper grease from NAPA on the bare metal at ground connections.

Does the ammeter show charge (and eventually goes towards zero) when driving?

Good luck - try to stay cool but be persistent in trying to figure this out.

Thanks guys, Jerry, How do I load test it, and what will that show me. Tim, I think this truck is a GMC in disguise (Garage Mans Companion) it likes to stay in it's comfortable little den. (that's a joke) Clean means ground to bare metal, not once, but twice, but as to your grease, do you mean that product that comes in a little packet. I was advised that that stuff is a insulator not a conductor. Proper cables means new 6VDC starter and ground cable, not 12VDC wires. No shorts means I tested the system with my VOM meter and could not detect anything draining the battery when the truck is turned off, but anything is possible. Staying Cool means, I plan my work and work my plan item for item, and build upon know and proven results, but I must admit I'm not sure where to go from here. The amp meter shows some deflection but not alot when charging, it moves from positive to center when drawing from the battery, could the meter be faulty? Please forgive my frustration, but after 6 years of restoration that special moment is fast loosing it's luster.


Dave

Most auto parts stores will load test your battery and check your charging system.

"High amp circular cell battery"- - - -What, exactly, does that mean? Do you have a brand name and model number handy? I've got a feeling you're using one of the sealed, all-position batteries. Those things are notorious for failing to produce the rated current flow, and requiring special charging techniques if they ever get discharged.

A load test involves putting a high current draw on the battery with a carbon-pile load resistor, and monitoring the terminal voltage while the load is being applied. As a hypothetical example, let's assume the battery is rated for "600 cold cranking amps". This information should be somewhere on the identification tag for the battery. A current draw of 1/2 that amount, or 300 amps, is put on the battery with the load tester for 15 seconds. After the 15-second load is applied, the terminal voltage at the battery posts is checked while the load is still applied. A 6-volt battery should have at least 4.5 volts at the terminals after the load is applied, or the battery needs to be recharged or replaced. A 12-volt should have aty least 9.6 volts after loading to 1/2 the CCA ratring for 15 seconds.

I'm betting you've got a bum battery. Trash the high-tech sealed battery and get a conventional wet-cell type that can be charged, then test the acid for proper concentration and give it a proper load test. Those horrendously expensive gel cell batteries might be all high-tech, but they're a big pain in the butt as far as I'm concerned.
Jerry

i have three operating trucks that are still 6VDC. there is nothing wrong with mine. in order for your battery to drain you must have a draw. hook a meter too it and start looking for it. three issues people have with 6VDC.
1.small cables
2.bad grounds
3.unattended current draws.

What is ampere hour capacity of battery or maybe better yet cold crank amp rating?
You just may not have large enough battery.

Check battery voltage while cranking. As said prev it should not drop below 4.5 or so.

Put in a known good battery. Drive 3 days and see how works out.

How long has starter been on truck? If that is rebuilt - was it done by good shop who know what they are doing?? Do NOT start fiddling with starter yet. Like most motors it is the least of your problems most likely.

Dan Bentler

Hi:

The battery is an "Optima" and as to good connections, yes they are clean and tight. The starter was bench checked last year and performed well. Two things: 1. what would you recommend for a good, high cranking amp battery, 2. Other than the battery and a possible short, what would be other things to consider. The 39 Chevy I had years ago had the same problem. Further, if any adjustments were to be made in the regulator what would you suggest in order to get the best charging rate. The regulator was also bench checked and found to be good!

God bless,

Dave

Optima batteries have had some problems since they moved their production facilities out of the country. For a quick check of the rest of the system, try a boost start with a 12 volt battery. If the starter runs well, the problem is almost sure to be the battery.

Another method of checking is to measure the battery terminal voltage as the starter is trying to run. If it's below 4.5 volts with the starter engaged, REPLACE THE BATTERY! You have tried repeatedly to charge it, and it's obvious it's not doing the job. Maybe Optima will take it back as a defective unit, depending on how long you've owned it, but I wouldn't trust any battery that I can't open up and check the concentration of the acid. If there is a heavy truck electrical supplier somewhere in your area, see if they can still get one of the 6-volt batteries we used to install in series-parallel truck electrical systems. They're about 50% larger than a stovebolt battery and they have much higher cranking amp capacity. You'll need to enlarge the battery box to accomodate the bigger battery case.
Jerry

Edit: I found a battery on the Optima website that has an 800 Cold Cranking Amp rating, which should be tested at 400 amps. Take the battery to someone with a professional-quality tester that can put a 400 amp load on it for 15 seconds. I'm sure you'll find a bad battery.
Jerry

I've got a cheapie generic 6v battery ... CarQuest brand I think. Truck starts every time unless I flood it.

Every car I've had an Optima battery in (12v Yellow or Red top) has eventually had starting issues. As soon as I go back to a plain jane Auto Parts store, Walmart or Sam's battery things are fine.

How old is it? I think Optima moved production over seas around the beginning of 09.

"I dread taking it out for fear of it not starting again for me"

Dave, don't despair. Every newly completed restoration/street rod build has a couple of bugs to be worked out when the job is done. It's always something simple but finding that simple bug is the challenge.

Just as an example, when I finished restoring my '36 Chevy pickup in 1976 I took it for a test ride around the neighborhood. Suddenly it stopped and couldn't be driven, pushed, or towed! The master cylinder push rod was adjusted improperly and the compensating port was not opening. This caused the brakes to lock at all four corners.

Once I finally got it home that day and fixed the problem it was fine and has not malfunctioned again to this day.

You WILL figure the problem out.

If you were to drive it every day the bugs would work out. I suspect the problem is just sitting too long between runs. Park on a hill where you can drift start it until you are more confident in the electrical system. I have driven cars with a battery having a dead cell in that way.

A different view on the Optima issues. I bought a 6V Optima five years ago and other than finding a way to fit it to my battery box, it's been bullet proof. I even let it run down to dead twice, once by leaving the dome light on for weeks and the second by doing the same with the tube type radio, and while recharging was a challenge it came back roaring both times. Granted my battery was made in the USA so there may still be an issue with the foreign built batteries. The info in this thread is good to know when it finally does die.

Yeah Vern, that reminds me of my first car when I was just 16. A 1941 Caddy flat head with next to no compression whan it was warmed up. That sucker wouldn't start to save your ars when it was hot, started great when it sat for an hour or so. Well I got in the habbit of always parking down hill. Nothing wrong with the battery, just a worn out engine. Now toward the end I would carry a 12v battery on the passengers floor board that would crank it fast enough to fire when it was hot. Still started great on the 6v when cold.
I'm a firm believer that the 6v systems with a lead acid battery are just fine, if every thing is up to snuff. The problems surface when the cables are to small, it has a bad component or there are poor connections resulting in voltage drop somewhere in the circuit. Add to that list a worn out engine or out of tune engine and your sure to have starting problems.
Denny Graham
Sandwich, IL

I have one 6v Optima that is about 6 years old and another one that is almost 3 years old (bought after they moved production to Mexico).

I swear by these batteries, not at them. For the second year in a row, I left the newer 6v Optima in my truck in an unheated garage in a deep-freeze (unheated) garage in northern New York. About a month ago, we had one day that got above 50. There was still plenty of unmelted snow off the sides of the roads, but the roads were dry. I thought that a drive in the Suburban would be a late winter treat (it had been left for hibernation in early November and had not been driven since late September). Without charging the almost 3 year old Optima, I cranked over the engine and it started after about 10 seconds of cranking (time needed to get enough gas into the carbs).

I'll continue to use 6v Optima batteries in my three 6v trucks until I have a problem.

If these batteries are so bad, why would Hagerty Insurance recently suggest that policy owners use Optima batteries? Especially since Hagerty has an excellent add-on coverage for free tows up to 125 miles (towing a truck with a dead battery costs $$$)?

By the way, if you let an Optima go dead, you must use a non-automatic 6v charger (the one time I did this, my cheap 6v charger would not charge the battery, I used a 5-10 amp 6v charger).

Guys:

In light of all that was saidand the fact that everything from the engine to the starter and generator are new or rebuilt, including the Optima battery, that is two years old, what is the best way to check for unintended voltage drains, 1. Take one of the cables off and put an amp meter across the line, or 2. go to the fuse block and go circuit by circuit and see if there is a drain there. Please be specific how I should best proceed and I will give it a whirl and let you know what I find.


God Bless,

Dave

Yes put an ammeter in series between battery and either battery cable. Light bulb will work also. Smaller the watt rating on lite the more glow at a low current level.

MAKE SURE truck is entirely turned off.

Dan Bentler

Dan:

Thank you my friend, I appreciate it.

Dave

This may sound stupid but many people have done it. When you turn off the truck, what position are you putting the key? All the way right (or counterclockwise) is accessory. All the way right is off and straight up and down is on.

I have never seen a switch on any vehicle that way.

yessir. I have 6, 49-52 Chevy cars that are all that way.
3 position: accessory-on-off. all the way left is accessory, straight up and down is on, and all the way right is off.

counterclockwise is left in my world .... there wasn't any accessory position on the 6V truck ignition switch, just OFF/ON - and didn't the 49-52 cars have solenoid starters? > off/on/start

Bill

Yes the did Bill, but if my memory serves me right they had a push button for the starter.
DG