1946-1949 6 volt Group 2 batteries

[Jay Friedman]

I've owned my '49 almost 40 years during which time I've bought for it several new 6 volt Group 2 batteries. The last one I had was an Interstate.  It was very good as it lasted almost 6 years, but the last month or so it seemed to be wearing out.  I called the Interstate distributor here in the Atlanta area where I bought it but was told that there were none in stock anywhere, even though it was listed on their web site.  I had previously bought the same type battery from Batteries Plus chain of stores.  When I called them I was told exactly the same thing as Interstate, even though they also had it listed online. The third place I called was NAPA who luckily had one in stock in a branch near my house.  I bought it for $140 and it works fine.

I'm wondering if 6 volt batteries will become more and more difficult to find.  Has anyone else had a similar experience?

An amusing sequel to this tale.  As '49 owners know, the battery is very heavy and is in a difficult place to access, since the battery box is bolted to the passenger's side of the frame way down near the starter.  To get it out you have to lean way over the fender to pull it up with a battery strap. I could accomplish this when young but now that I'm a senior it's not so easy.  So, I asked my wife to help get out the old one. It was a major effort by the two of us with lots of pads to protect the fender, and we had to use a wheeled dolly to carry it to the car. A husky young guy sold the new one to us at NAPA. He carried it out for us with one hand and at the same time held the door for us at the entrance. He really made us look bad. 

[J. Russo]

Jay,

I've had a NAPA 6 volt for a couple years and it has been very reliable.
I also bought a DEKA 6 volt battery and it doesn't seem to hold a charge as long as the NAPA battery.

If you read the fine print, both batteries are made by the same company.

[Jim Miller]

I use 2 six volt optima batteries in parallel on my 41 and 49. Together they fit in box nicely and I can lower one at a time down in that canyon - much lighter. Also adds some zip to the cranking amps.

[Jay Friedman]

Jim, any chance you could show us a picture of how you set up the cables on your 2 six volt optima batteries wired in parallel?

[Julien Abrahams]

In relation to this topic (not hijacking), I was wondering how long do your batteries last in general?
In my cars I get 10 years of life quite easily. The only thing I do is that I disconnect one battery lead when I park the car and reconnect it when I want to drive it.

[TonyZappone #2624]

Jay, I have one Optima battery in my '47.  Its been in there 13 or 14 years, and works well.  Easy to get in and out also

[Jay Friedman]

In relation to this topic (not hijacking), I was wondering how long do your batteries last in general?
In my cars I get 10 years of life quite easily. The only thing I do is that I disconnect one battery lead when I park the car and reconnect it when I want to drive it.

Julien, A friend of mine here in Atlanta had a 6 volt battery last 10+ years in a '49 Cadillac and I have heard of others lasting that long. However, I have never had such good luck. The longest I can remember that I have had a battery last in an antique car or a modern car is 5 years or so. I imagine disconnecting the battery when parking like you do helps a lot. Maybe I'll start doing that.

Jay, I have one Optima battery in my '47.  Its been in there 13 or 14 years, and works well.  Easy to get in and out also 

Tony, I did have a single Optima 6 volt in my '49 many years ago.  It worked well until one day I left the dome light on overnight or something equally dumb (I don't remember), and the Optima became completely discharged.  Apparently there is a special procedure to charge them back up in such a situation, but I couldn't figure it out.  I then went back to a standard battery. Maybe I should switch back and I definitely agree they are easier to get in and out.

Actually, the reason I started this thread was because of the difficulty I had finding a new 6 volt Group 2 battery from the vendors from whom I had previously bought them. Interstate and Batteries Plus no longer seem to stock them. I was particularly concerned about Interstate since my last battery from them lasted a fairly long time and worked well.  I'm wondering if this is a general trend and that it may not be easy to find such batteries in the future.

 

[Classic]

Type 2 batteries are 9-3/8" high.  Type GC2 batteries are 10-5/8" high. Length and width of both are the same.  If you can live with the extra 1-1/4" height, they are a possible replacement.  GC2 batteries are Golf Cart batteries and are widely available - Walmart, Costco, Sam's Club, Interstate, NAPA, etc.  They are used in other applications as well - Motorhomes(4 or 6), old farm and construction equipment, etc.
This may help.
Gene

[toybox]

I have been running Optimas Inside the old stock large case six volts. They fit in on an angle and the posts' are right where the stock ones were before they were cut out. Nobody has ever noticed at showtime. The trick now days is to find the old large cases.  Tim

[TJ Hopland]

Glad someone brought up the Group 2 vs GC2.  I was wondering about that since that is what I see in stock everywhere and the few things I have dealt with (tractors) used likely because space didn't tend to be a problem. 

For the person that is running the parallel ones how did you do the cables/connections?  Custom cables or did you find something for heavy equipment that worked well?

The issue with a weak or dead optima is they will suck every amp of juice you give them which can often overload and or damage what ever you are using to try and charge them.  This could be your gen/alternator if you got it started but it was still pretty weak or your charger. 

Many of the 'smart' chargers today will just overload an shut off.  I found if all you have is a charger available to you set it for its lowest setting, ideally under 2 amps and let it go like that as long as possible.  At some point it will be charged enough that you can switch it to a higher mode and it will do fine.  Some chargers will even trip out or not work that low.

What they say the proper process to revive one is is to get a similar size capacity wise battery fully charged and connect them with a good set of jumper cables.  You can then connect the charger to both batteries or wait for them to equalize then charge one at a time.  The idea is the good battery can supply the 100's of amps it takes to partially recover.

As long as you are aware of that characteristic I really didn't have a huge problem living with them and its not why I quit using them in the normal 12v form for fairly normal applications.  The small form factor of the 6v may be worth the extra hassle if I was to have something 6v. 

[conyankee2]

I would also love to see pictures of the 2 Optimas running in parallel setup!

I've been running an Optima red top for 12 years now and just tested it both at a local auto parts store, as well as on 2 of my handheld battery testers (digital and carbon pile). All results were the battery is in 'good condition'. When not driving I religiously disconnect the positive lead, and hook it up to a 5amp battery tender.

Coincidentally, I've been looking for information about what the OEM battery looked like for my 1947. According to the Authenticity Manual 2nd edition Summer 2021, page III-20 it says all 1942 - 1947 batteries were a 6 volt Delco type 17K3W of 115-ampere hour capacity (modern equivalent Group 2). Specifically, that "the battery has 3 cells each topped with a black cap as shown in the photo below". This is the only reference I can find to the black caps as it specifically relates to a 47 OEM Cadillac battery. Does anyone else have info / photos?

I ask because for authenticity purposes I would like to purchase an authentic/period correct-looking battery, but most I've found specific to Cadillac have yellow tops (see picture below). I would assume the authenticity manual is correct, but just find it odd I can't find any other corroborating information online (or perhaps I just haven't looked hard enough). Any info would be greatly appreciated!

[TJ Hopland]

Did someone maybe mention 3d printing battery cases?  Was it in one of our 3d printing threads or a battery thread?   Seems like a good application for 3d printing and would just fit many of the printers.  Won't likely get you show quality but as far as not standing out in a driver car maybe a perfect option?

[Mike Baillargeon #15848]

Jim, any chance you could show us a picture of how you set up the cables on your 2 six volt optima batteries wired in parallel?

I've been screwing around with a 1940 V16 and this is how I put two 6 volt Optima batteries in parallel.  (see pictures)

The cranking amps that this generates and the use of an electric fuel pump really takes pressure off the starter....

I've had one of these 6 volt Optima batteries in my 29 roadster for 12 years!...And it was working fine when I switched it out for another one.  I figured the old one was going to die at some point and leave me stranded.

I think the key to long life on any of these batteries is having it hooked up to a Battery Tender to maintain a constant voltage even when the car is not in use.

Here is a parallel and in series website....

https://www.atbatt.com/how-to-wire-6v-batteries-in-series-or-parallel-configuration/

For the custom cables I use these guys....

https://www.batterycablesusa.com/00-gauge-2-0-awg-marine-grade-battery-cable-with-ends

You tell them what ends you want and what color and what length....all pretty reasonably priced....I use 00 gauge, but you can go thicker if you want...

Mike

[Jim Miller]

Here a photo re: my earlier post

[TJ Hopland]

So those are top post to stud adapters and home made buss bars?

[Rossoroo]

British Columbia checking in.
Just phoned the local parts place and 6 volt group 2 batteries are available here.
Parts guy owns a 48 Chrysler Windsor and said he got his 6 volt from a tractor supply store.

[conyankee2]

Mike - A V16...VERY jealous. Have always loved those since the first time I saw one. Nice battery setup!

Jim - Thank you for sharing as well, looks good!

Ross - Interesting you say that about tractor supply. The closest batteries I've been able to find 'looks-wise' to what the authenticity manual shows, actually all seem to say 'tractor/farm equipment/commercial'. Show us what you end up w/ along w/ the specs. Do you know what brand?

[Jim Miller]

So those are top post to stud adapters and home made buss bars?

I believe so. Jack Hoffman made this set up when he restored the car. For my 41, I used 1/4 inch copper and made the bars.

[TJ Hopland]

With the stud adapters you would not have to use the bars, you could just use short cables which may be easier to find than copper bars for the average person.  Short cables are commonly used on heavier equipment where they are using multiple batteries.

I do like studs especially when there is more than one wire involved.

 

[Rossoroo]

Ross - Interesting you say that about tractor supply. The closest batteries I've been able to find 'looks-wise' to what the authenticity manual shows, actually all seem to say 'tractor/farm equipment/commercial'. Show us what you end up w/ along w/ the specs. Do you know what brand?
[/quote]
No I don't have any brand names for tractor 6 volt batteries. I heard it from the local parts guy.
The 6 Volt I have in my 49 is a "Power Surge" which I obtained through the local industrial supply shop which I guess is similar to a tractor supply. Mostly mining and logging in this neck of the woods.