The Stovebolt Site Forums The Shop Area General Truck Talk 8 volt battery?

I'm pretty sure the salvage yard guy was pulling my leg. I wanted to buy a 12-volt generator from him for my conversion, but he said all I had to do was use an 8 volt battery --- better cranking and no other conversions needed. Any laughs or thoughts?

By the way --- thanks to all who've helped. My '51 3600 was purchased two months ago and now has new brakes and starts every time. I think it was sitting since '94 but not sure.

Colorada51three-quarter,

No leg pulling in Windsor! They do (or did) make a 8 volt battery, and people did put them on the 6 volt rigs to get them going a little easier.

On Santa's list of the ten dumbest things to do to your rig, it might be real close to the top.

While easier to do than a full blown 12 volt swap, it doesn't get you much.

You will soon see people pop in to tell you a well maintained 6 volt system with all the proper sized cables is the cats meow!

Your original idea of the 12 volt generator is OK too, but better options exist unless you are trying to keep the old truck looking 'factory'.

Stuart

Thanks Stuart -- I wouldn't mind staying 6-volt but the brand new 6-volt battery with good cranking power doesn't hardly even turn the engine. I got good advice last time around about the cables and so on, so might try that.

By the way --- any body listening I need two "Chevrolet" hub caps, 9" inner diameter for the 3/4 tons. Don't matter if they're not perfect.

I have a 1951 3800 truck and tried the 8 volt battery thing. Yes, It had more starting zing but every time I turned around I had blown light bulbs. Headlights, stop , turn signal, dash ect. I cleaned up my grounds and went back to a 6 Volt battery, light problems cured.I think the trick with an 8 volt battery is to balance the output of the generatory via regulator to charge without over charging. My 6 volt generator put out over 12 volts unregulated.

no leg pullers in calif. either. there IS such a thing. I went that route for a while on my pick-up and finally just changed it to 12v.(for stereo,etc)
BUT..automarc is right on..with a properly maintained 6v system you should do just fine.
It also blows a lotta people away,"WOW that things still 6 volt?" clean connections,proper ground straps,right size cables,and,did i mention clean connections?

Okay --- save the 6 volt would be cool. When I had the truck on jacks and idling, the back wheels spun slowly. That was trans friction, no big deal --- but could that add extra load on the starting? The only connection happening in this system is battery-starter-coil-etc. as I've temporarily disconnected everything else. The engine purrs at low idle nicely, so I don't think there's issues there. I guess I should clean all the connections and replace the cables...

There is no "right" way to do an 8-volt battery installation, and I grew up around a shop where we had the best charging system tech in the southeast- - -my father!.

In order to recharge an 8-volt battery, the voltage regulator must be set at 9 volts. That burns out bulbs, headlights and everything else. It's also rough on the gas gauge and all the other electrical accessories including the coil and points. Normal charge voltage is about 7.5 volts with a properly-adjusted regulator working against a fully-charged 6 volt battery.

Big battery cables, #0 or larger, and very clean connections and grounds will keep a 6-volt system starting just fine except in extremely cold weather. Make sure there's at least 4.5 to 5 volts available at the "+" side of the coil while the engine is being cranked. Dirty contacts in the ignition switch or poor connections between the switch and the coil will rob voltage from the coil, resulting in a weak spark, even with good cranking speed from the starter!
Jerry

An 8v battery was a common solution to starting problems on 6v vehicles (often used by farmers who had 8v tractor batteries laying around?).

As stated above, this "solution" is an admission of defeat and of failure to solve the real problem(s):

1. weak/old/ready-to-fail starter
2. weak/old battery - a 6v Optima battery solves this one
3. Wrong (too small) battery cables - 1/0 or 2/0 (0 or 00) gauge cables are preferred (2 gauge were original for 6v, and 4 gauge for 12v)

If you are sticking with 6v, get the right cables. I bet that 90% of people who have a 6v vehicle have wrong-gauge battery cables (especially the ground cable), unless they have already replaced the cables.

I am speaking from first-hand experience (I foolishly put off getting the correct cables for about 5 years - and had to do a lot of push-starting when the engine was warm).

Don't forget about the poor old dude that does all the work! Mr. Starter needs good brushes/springs, clean commutator and good bushings.

Stuart

If you drop in a 6V Optima, use 0 or 1 gage (at the smallest) cables with clean connections and it cranks slow you have a bad starter.

Yes, and then your problems will be over (unless you have bad main bearings and/or a cracked block and/or a . . ).

Tim

I wrote in a few months back with problems getting my 8 volt battery to charge. Those problems are straightened out now, and I am running on an 8 volt battery. The only change I've made so far is to the voltage regulator, like what Hotrod Lincoln wrote. I haven't yet had problems with blown bulbs, other than one headlight that was at least 30 years old anyway, and my gas gauge hasn't worked as long as I have had it. But as soon as this battery kicks, I am going back to 6 volts. I wish I had found this site about a year earlier!

I recently replaced my 6-volt with a new 6 volt.Truck was turning slower and slower but would fire right up with 6volt start on charger or 12 volt booster pack.New battery changed nothing and wires are corect sise with clean grounds.Took my starter in to have nothing found wrong just the usual road grunge and grease.The shop completly dissasembled and cleaned it.IT now cranks over on 6 volts as fast as it did on 12

Slow Rider,

Was it the starter that made the difference?

Stuart

Ihad taken my new battery back to the store as i was sure it was defective.It was not.Thats when i took the starter in.The gentleman that did the work works mainly on old vehicles'He has all the old school tools and testers and does alot of work on those couple of miilion dollar councourse cars.He totaly dissasembled tested,solevent cleaned it.It required no new parts and no machineing.Only the bushing was replaced.The only other thing he noted was that the mash swicth was in need of a little snugging.This is the original starter that had only had the brushes replaced once sinse ive owned it.I never knew a 6 volt starter could turn so fast.Ron

I put in a new Optima 6 volt battery and used 0 gauge wires with the ground to a starter bolt and it really cranks over good, fires the old GMC 248 like a good thing, no need for 12 volts.

Be sure to check in the Electrical Bay, as well as the electrical stuff in the Tech Tips -- Randy Rundle has some good gouge on all of this.

Regards,
John

I cleaned all the crud off my coil (on the 53) and I thought it said 8 volts. I was expecting it to have a 6 but it was 8.

Did these trucks have an 8 volt coil or was this a coil from something else?