8 volt battery C-1

[Jack H.]

Re: 8 volt battery C-1

Thanks, Duke! Think of a battery holding charge as a pail holding water. In order to put water into the pail you must pour from ABOVE the upper rim of the pail. The analogy holds for charging a battery...

In order to restore lost charge (charge in motion is called 'current'), the driving voltage has to be higher than the battery's nominal voltage level. So, a voltage regulator dialed in for charging 6V batteries will be at a disadvantage when it tries to maintain or 'top off' an 8V battery.

WAY back when, it was reasonably common to get better engine cranking performance by substituting an 8V tractor battery for a car's 6V battery. But, the good ole electrical shop boys who did these swaps also 'tweaked' the voltage regulator to match.

It just turns out that 8V is close enough to the loci of charging conditions for a properly designed 6V system to work. But, you are 'pushing' the v-reg and generator towards their outer limits...

Since batteries are always charging/discharging in an automotive setting, the absolute voltage level of the electrical system is dynamic. Various electrical components in the system HAVE to be designed to work across the system's dynamic range and are therefore tolerant of different specfic voltage levels.

That's why the 'tractor trick' works. The 8V level falls within the typical range of a 6V system's variance. But, if the voltage regulator is dialed in for 6V nominal operation, the 8V battery will be maintained below its peak...

[Troy P.]

Re: 8 volt battery C-1

Ted, the correct positive cable is 14.5 inches. So the Packard number would have a 14 in it not a 16. Also the 1L means it has a lead terminal. The correct cable would have a lead coated brass terminal. So for close to original you need a Packard CP-14 or 1U-14.

[Russ U.]

Re: 8 volt battery C-1

If having the word Delco on a battery cable makes anyone's car crank more rapidly, then by all means jump on that $160 battery cable before it slips away.

However, if the word Belden would work just as well, go to your NAPA store and spend $18 for part number 711431. This will also get you a 1 gage, 14" cable.

Jim

This has been a very helpful thread, so thanks to all the participants. And a special thanks to Jim Lockwood for providing the NAPA part number - 711431. The NAPA online system does NOT associate this part number with 53-54 Corvettes, so you have to ask for it by the part number.

This thread reminded me that my 54 turned over and started much more briskly than my 53 does now. I could not figure out why - everything on the electrical side seemed pretty much the same between my old 54 and my 53. After reading this thread, I checked the positive cable on my 53. Sure enough, the cable on my 53 was one of the skinny 4 gauge types sold by the Corvette parts houses.

So I went to my local NAPA store, and they had 2 thick positive cables in stock (part #711431). I hooked up the cable, and then cranked the engine. Yep. A lot more oomph.

Thanks guys.

Russ