maineolds

Anyone know how many CCA a 6v battery had in a 1949 Olds 88 back in the day? I can’t seem to find any specifications for the batteries that were used back in the day other than the simple fact they were 6volt.
my NEW Oprima 6v with about 800 CCA turns the 303 v8 over very slowly. That’s with a perfect starter and 00 gauge cables. If I hook up another battery in parallel like I’m jump starting it the olds turns over with ease.
I’d like to know how todays batteries compared to the old ones when it comes to cranking amps.

Olds64

Have you put a multimeter on your new battery to test the voltage? I've gotten a bad Optima 12V battery for my 71 Oldsmobile in the past. Luckily, I bought it at Summit and was able to return it.
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maineolds

Yes, I’ve tested with a multimeter and a carbon load tester. The battery is good. It “works”, but it’s SO much better with another battery in paralel. That’s why I wonder about the stock cranking amps.

Vintage Chief

Ensure you're using the absolute shortest cable runs since the longer the run the greater the resistance which can/could impede CCA being delivered.

Charlie Jones

What thickness battery cables do you have?
You need big, thick cables on a 6 volt system.
At least 2/0 gauge.
A skinny 12 volt modern cable will cause this problem.

VC455

You're right about there not being much historical information on 6V battery capacities.

But there is information on later 12 V capacity. Between 1949 and 1970, there wasn't much difference in battery technology other than thinner cases and thinner separators--both of which allowed more active material in the battery. We can use data from 1970 to develop a conservative estimate.

A 1970 Delco 12 V, Group 24 had 335 CCA. A NorthStar Group 24 AGM like I currently have in my Vista Cruiser has 840 CCA.

An Optima 6 V AGM currently advertises 800 CCA. So if we go back in time, following the 12 V regression, we would have had a 6 V in 1970 with 320 CCA.

The 1949 value would have been less because of the thicker case and separators, but this gets you in the ballpark for that 1949 CCA.

maineolds

Thanks for the thoughtful response! Just what I’m was hoping for. Happy thanksgiving!

Tedd Thompson

AS I remember it, most all 6v engines turned slowly. 49 isn't far from the human crank start engines days, and they all seemed to get started in the Olden Days. Hard starts were usually the cause of pitted points, old wires, corrosion and too small of battery cables. If every thing was up to good or better, cars would start with a slow turnover. It's that we have gotten used to 12v cranking and instant key starts with modern cars... Tedd

BangScreech4-4-2

"Good" and "works" are subjective terms. What actual value did you get?

maineolds

Quite right Ted. One reason I’ve kept a 6v system is because it dosnt hide weakness. If things are as they should be the car will run as it did when designed. My question was not to compensate for problems but rather to see if anyone was familiar with old specs. Thanks to the research and wisdom shared here we now know what those would have been. Now future enthusiasts can find the answers. It’s a great thing to be able to share wisdom in this would before our time is done. I’m thankful for this group and all the helpful input.