8 volt batteries

[Richardonly]

Hi All,

I have seen pics of 6 volt cars in which they have installed 8 volt batteries.

I do not believe that bulbs, wiring or anything else has to be changed, but I do have several questions.

At present, I do not have any trouble with the 6 volt in my 1948 Fleetwood.  However with power windows and an air conditioning system (supposedly installed in 1951), I do notice the generator indicator on full charge when running the car in the city.

What is involved with installing an 8 volt battery and what benefits are there to it?  Does the 6v generator restore power to the battery easily or does it work harder to do so?

What is the main benefits to doing such a thing?

Thank you, Richard

[KD]

I was wondering the same thing, My 1940  series had one in it when I got it
Ken D CLC#26801

[Dave Shepherd]

Assuming the 6v battery is in good condition, the wiring is is good shape as well as all the connections, proper size battery cable and grounds, reg and gen outputs are correct,. 6v can get the job done.  That said 8v has more back up power but the gen would be pushed to its limit to maintain a 8v battery which generally is at about 8.5 volts fully charged.  I have done this conversion on an older Buick and the best I got out of a good gen was about 8v, more than that is was really running hot.   

[Jay Friedman]

Years ago I installed an 8 volt battery in a daily-driven 6 volt '51 Oldsmobile which would not start well when the engine was warm.  With the 8v battery tt started better but sealed beam headlights would not last very long.  So I cleaned up the grounds, bought new battery cables, switched back to a 6 volt battery and the starting and headlight problems were both solved.

[bcroe]

8V is a band aid fix, which isn't needed if the electrical system is brought up to par. 
Bruce Roe

[Richardonly]

Thank you all for replying.

It appears that the 8v may give it a "kick" in starting, but beyond that, it strains the system and components.

Imagine a 33% voltage increase going through 64 year old components!  It truly does not sound like a good mix.  It makes one wonder how changing a system to 12v can stand the change.  I was aware that in the 12v converstion, the bulbs must be changed to handle a "TWICE the voltage" powering it.

They originaly changed to 12v as it was more reliable, and it must be so as we are still useing it over 50 years latter.

It was not something I needed, but was trying to find the pros and cons to changing to an 8v.

Thank you again.

[pauldridge]

The primary reason for the change to 12V systems was to cut down the size and weight of the wiring (same reason some lux. cars are now going to 24V).  More voltage, less amperage required, hence smaller wires needed to power a given component.

That said, there is no cause for concern in converting an older 6V car to 12V, as the original larger gauge wire in those 6V volt systems will be loafing when asked to pass just half the amperage of a 6V system.

I've switched my '40 60 Special over to 12V, including replacing the generator (and regulator) with a modern and inexpensive self-regulating alternator.  I now have plenty of power for my added air conditioner and electric cooling fan.  Be happy to pass along my installation notes and updated wiring diagram if anyone is considering a similar upgrade.

If your primary concern is the fact that your generator is working overtime to keep up with the demands of an A/C system, you might want to consider installing a 6V alternator.. these are widely available, even in Positive Ground versions, and include voltage regulators, so you can eliminate another source of problems in your original system.  (And, it would probably be cheaper than buying a relatively rare 8V battery, and re-adjusting your regulator)

[cadillacman]

Hi two words..... Optima Battery 

fitted it to my 49 (6volt yellow top) car has improved, i also changed the leads OO gauge wires and 6v electric ign.
overkill..but their is nothing worst than going to show and the getting the jump leads out to go home.

[Jeff Maltby 4194]

Hi two words..... Optima Battery 

fitted it to my 49 (6volt yellow top) car has improved, i also changed the leads OO gauge wires and 6v electric ign.
overkill..but their is nothing worst than going to show and the getting the jump leads out to go home.

You meant Red Top 6v Optima.

[cadillacman]

ermm no their yellow in the UK 

[Jay Friedman]

Cadillacman,

If you have a 49 you ought to join the Forty Niners Chapter of the CLC.  It's a non-geographic based group within the Cadillac LaSalle Club devoted to '49s.  Dues are $8 (or £5 if you're in the UK) per year, in return for which you'll get a quarterly (March, June, Sept., Dec.) 8-page illustrated newsletter, The '49 Times, on running, repairing and restoring '49 Cadillacs.  (Your story about installing an Optima would make a good article.)  We have over 200 members.  If interested send a cheque for $8 or a 5 pound note to: Jay Friedman, 1530 September Chase, Decatur, Georgia 30033 USA.

Jay

[Jeff Maltby 4194]

ermm no their yellow in the UK 

Yellow tops are 8 volts.

[cadillacman]

Hi, they 6volts and they are fitted in the back of VW for the media in the UK.
I have also PM'd you about the 49 chapter

[robert G. smits]

The best advice you have received is from Paul Auldridge.  Adding extra battery reserve power will not solve the problem of overloading the generator because of added electrical equipment although it will help with starting when hot.  Get an alternator that will handle your load and quit worrying, especially if you plan to tour.  Just my two cents worth.  Bob Smits #2426

[76eldo]

Properly rebuilt Generators and Starters will have NEW field coil units.  If you have excellent working components and good clean grounds, you have no need for an 8V battery at all.

Make sure you have a ground strap from the engine to the sheetmetal of the body, and also a good ground connection from the engine/trans to the frame.  You can add this discreetly down by the trans mounts.

Brian