Optima battery

[BuickTom87]

Anybody running a 6volt optima battery, im planning on using them on all my cars. I just want to see how some of you mounted them up ..

 

First, I plan on putting one in my 41 century and then my 38 century . Just want to see how it looks and mounted up in the engine bay . 

[EmTee]

Looking at my '38, you'll obviously need to fabricate a specific hold-down.  The batteries have a great reputation for performance and reliability, however, if I were to install one in my Century I'd probably integrate a cover into the battery hold-down so that it doesn't stick-out visually inside the engine compartment.

[edinmass]

I resisted them for years, and now they are in all our cars. In the old days, it they would  be good for 10 years, now that they’re made in Mexico they’re good for about six.  There’s definitely a learning curve with them and you need to know how to charge them if they get substantially discharged. I installed two of them in every car. I like the extra amperage. Of course, the cost is very substantial.

Edited April 20, 2023 by edinmass (see edit history)

[Brian_Heil]

Invested years ago in a smart 6V/12V trickle charger I move around to the different cars.  I get at least 5 years out of the Tractor Supply 6V batteries.  Optima is a fine battery but their life is not worth the price. 
 

 

[edinmass]

The best argument for them is no hydrogen gas or acid damage to a high point restoration. Having two in one spot also is convenient if you have a bad cut out so there is another battery to run on, of course you need to keep the back up charged. 
 

For the record, I had one go bad and ruptured in place. The gel leaked out. 

Edited April 20, 2023 by edinmass (see edit history)

[Brian_Heil]

High point restoration, what’s that?  Ha. 
 

An inexpensive acid neutralizing battery mat is another good investment.  They don’t last forever so keep that in mind. 
 

Hydrogen gas build up can be an issue especially in an enclosed battery box such as on a pleasure boat.  Required by law but always thought of them as counter productive for this fact. 
 

The 100+ year old floor boards above the 6V don’t seem to mind.  No comment about methane. 

[27donb]

I used an optima in my 2754cc Buick and my 62 VW that is converted to 12 volt. 

 

All my car batteries are kept on maintainers year round to try and maximize battery life (I can only drive one car at a time while others sit). 

 

The optima batteries performed fine and lasted about 6 years.  My complaint is that they died without warning, and when they were done they were DONE.  Couldn't even light the headlights on the Buick. 

 

My 54cc now has a conventional 6 volt battery.  It is about 6 years old and last year, it seemed to crank a little slow, so I know I am looking at a new battery this year or next. 

 

Both optima's died with no warning.  No slow cranking, just click, dead. 

 

They never lasted longer than regular batteries for me.  Cost and inconvenient no warning failure considered, I don't use them anymore. 

 

My 2 cents... 

Edited April 20, 2023 by 27donb (see edit history)

[Barney Eaton]

This has been ask before and I have not changed my story..... 

My '39 Century would go thru a conventional battery every year.   After about 3 years I decided it was time to try another route. 

I went with the Optimua  and the main benefits were... it was easier to install did not weight as much as the old original version and I was getting 3-4 years out of them. 

My solution to the bright red color was a cheap plastic waste basket from the dollar store.   Drilled holes for the + and - terminals and cut the sides to length. 

I never used anything but heavy duty cable ties to hold it in place.    

[JFranklin]

If you are getting such short life out of both types of batteries, I think you should search for the reason why. I get 7-10 years from conventional batteries so I never considered an optima. 

[nat]

13 hours ago, edinmass said:

if you have a bad cut out so there is another battery to run on, of course you need to keep the back up charged. 

     One battery and a pirate's vocabulary is all that anyone used to use.  If two batteries are to be used a "1, 2 both" switch allows them to charge/power equally, separately or to be isolated as a backup.

     They are available for half this price but here's one that should be reliable.

https://shop.hamiltonmarine.com/products/dual-battery-selector-switch-3-8-stud--315-amps-cont--450-amps-int--57463.html

[edinmass]

Interesting switch, but no where near heavy enough for a six volt car……….would need a switch that can handle 1200 amps minimum.

[Hubert_25-25]

For many of us, the Optima does not show.   Woodys custom shop is making a box for them which I use in the cars where the battery needs to be hidden.  This is the Optima in this box in a 1941 Bantam Jeep.

 

https://www.woodyscustomshop.com/porsche-356-items/

Hugh

 

  

[Morgan Wright]

34 minutes ago, edinmass said:

Interesting switch, but no where near heavy enough for a six volt car……….would need a switch that can handle 1200 amps minimum.

Yeah, and you'd need 00 gauge wire all the way to the switch and back.

[Shootey]

I had a traditional battery installed in the trunk of my 1966 Lotus Elan with a plastic hold down clamp. At a track day at Laguna Seca the hold down got blown apart  and the terminals sheered off.  I don’t imagine old Buicks will be doing track days at Laguna Seca. My fix was to fabricate a metal strap to bolt the battery to the rear bulkhead. A little unauthentic but safe. 

[critterpainter]

One of the advantages of using an Optima 6v battery in the older Buicks is that you are getting 800 CCA not 600 or 650 CCA like most lead acid batterys produce.   Its realy noticeable on a 320 engine.

 

[Bloo]

The biggest thing of all is that the posts do not corrode with an Optima.

[Morgan Wright]

One great thing about the Optima is, for early cars, it fits right in the original battery box. Diagonally, but it fits.

[Den41Buick]

I am wondering what the reasonable longevity should be for a trickle charged 6 volt Optima battery? I am at 10 years and I am having to jump on high but it still starts.

[Hubert_25-25]

10 years is about the life of these batteries.  I would save yourself the trouble of it failing out on the road and replace it.  

[BuickTom87]

I saw someone where on here but not sure of some Packard or Cadillac running 2 optima 6 volt batteries but they are ran in away that it’s only really one . 
 

Im wanting to do that on one of my cars and see if the voltage stays flat. My 38 Buick the voltage drops basically really low if have the headlights on and other accessories. We swapped out the voltage regulator it got better but . The mechanic recommended we ditch the battery and go with a optima 6 volt 

[Bloo]

34 minutes ago, BuickTom87 said:

I saw someone where on here but not sure of some Packard or Cadillac running 2 optima 6 volt batteries but they are ran in away that it’s only really one . 

Connect them in parallel, + to + and - to -.

 

34 minutes ago, BuickTom87 said:

Im wanting to do that on one of my cars and see if the voltage stays flat. My 38 Buick the voltage drops basically really low if have the headlights on and other accessories. We swapped out the voltage regulator it got better but . The mechanic recommended we ditch the battery and go with a optima 6 volt 

Generators charge very little at idle if at all. That is normal. On the other hand, if the dimming is happening revved up, it might depend on how many accessories you are talking about. A 38 Buick charging system is capable of about 25-28 amps. I don't recall exactly. 1937 has a 25 amp generator, and as I recall 38 has ever so slightly more.

 

If your battery is fully charged, and you don't exceed the current (amps) the generator system can supply, you should have the voltage the regulator is set to as you go down the road. That is probably 7.5 volts at room temperature.

 

If your accessories do draw more current (amps) than the generator system can supply, then you are starting out at about 6.3 volts with a fully charged battery, as that is the natural voltage of a 6 volt battery. It goes down from there as the battery discharges. The bigger (electrically) the battery is, the slower it drops. The difference in brightness between 7.5v and 6.3v is a lot. You can easily see a 0.2V difference in lights.

 

 

Edited December 9, 2023 by Bloo (see edit history)

[Hubert_25-25]

Tom,

This is an interesting post because this is exactly the same situation that I am currently working on.  My client has a 38 Buick Special.  The 6 volt optima is the battery to buy.  In this case, 2 of them.  Instaling them in parallel keeps the voltage the same but doubles the capacity of charge on hand.   The Buick has a long battery box that can hold the two 6 volt batteries, but they are one behind the other, and not next to each other.  So the wiring is like in the "6 v Batteries wired in parallel" drawing that is shown below.  Then I found these cables that look like they are up to the task because they have an extra post, so there is no need to make any modifications to any wiring.  There is a common set of these kind of cables that are 7" or 8" long each.  These are great for batteries that are "side by side" to each other.  You can find the red or the black on Summit or Rock Auto.  I listed the part numbers at the very bottom of the attachments in case someone wants to put 2 batteries next to each other.  The short cables are readily available.

They also make these cables 14" long each.  You need this extra length for "end to end" batteries.  The red postive cable appears only to be available from "Quick Cable", so order both red and black from them.  Part number is 7755-001 (black) and 7756-001 (red).  Note that there are lots of pictures of these on the internet, and they look like a pair, but the cables are sold separately.  I have also ordered the red cable from two other companies trying to get the correct red cable, and they ship the wrong one.  Order the 14" cables direct from Quick Cable, as they are the manufacturer. 

 

I would post a picture, but I keep running into problems with other vendors trying to get the red 14" cable.  Zoro has the wrong one listed, then I tried another vendor and I am still waiting.  Once I resolve with the last person, I will either have the correct cable, or I will order it direct from Quick Cable.  I work on numerous 20's and 30's cars.  A single 6 volt optima works great, but in many of the 8 cylinder cars, there are dual 6 volt optimas installed to provide that insurance of having more starting power. 

Hugh 

 

Edited December 10, 2023 by Hubert_25-25 (see edit history)

[Brian_Heil]

And the CCA (cold cranking amperage) which is what you are really after is additive as well in this configuration.  The 6V Optima I just looked up is 800 CCA so you would have 1600 at the ready.

 

Well done as always Hugh.

[MCHinson]

This doesn't answer the original question about how it looks in the engine bay, since the battery is mounted under the seat on a 1937 Buick, but on my 1937 Roadmaster I have two Optimas wired in parallel. I have nice heavy duty cables on them. They provide more power than needed but I use two of them because I like to use the original tube type radio (which draws quite a bit of current) when parked at shows. I have 40's tunes downloaded onto an ipod and use a small "Micromitter" AM transmitter to send tunes to the radio. I don't play the music obnoxiously loud but people really like to hear period music while admiring the car. I can leave the car parked with the radio on for several hours at a show and the car still starts just fine. When I get home, I use a charger to top off the batteries so the car is ready for the next show.  

[BuickTom87]

Thank you for everyone help, I have 2 optima’s 6volt batteries ready for my 32 Buick 97 series . Since the battery in there was shot and leaky . 
 

The battery box there already in the car , we are going to re fabricate  it since it has some damage from the years of battery acid. 
 

 

[alsancle]

A single one of those batteries is more than enough to crank that engine forever.  Consider a 3 way cut off switch that allows you to switch between either battery and Off.   This is my new way of doing things.   It eliminates the need for a jump in a bad situation.

[Skidplate]

I was wondering when the 6V battery conversation was going to come up. Having a background in electronics it seemed well within reason to run 2 6v batteries in series; run a modern 12v alternator to feed the top battery, then run all your lights and 12v accessories off that point and pull off the middle (the 6v point) for the things you don't want to convert, I.e., factory gauges and fans. I installed a few High capacity switches where necessary to energize what I wanted power to in any particular scenario... and so far everything has worked. My gauges are accurate, My lights with all new 12v bulbs all shine really bright. My electric fuel pump with the feedback line back to the tank (new fuels don't work too well with the early confirmations) works great. 
I had to figure out what cables I needed between the two batteries and from the alt and to the rest of the system. But given infinite time and money and patience and did I mention time, money and patience? All has worked out. So far.

[Morgan Wright]

21 hours ago, Skidplate said:

I was wondering when the 6V battery conversation was going to come up. Having a background in electronics it seemed well within reason to run 2 6v batteries in series; run a modern 12v alternator to feed the top battery, then run all your lights and 12v accessories off that point and pull off the middle (the 6v point) for the things you don't want to convert, I.e., factory gauges and fans. I installed a few High capacity switches where necessary to energize what I wanted power to in any particular scenario... and so far everything has worked. My gauges are accurate, My lights with all new 12v bulbs all shine really bright. My electric fuel pump with the feedback line back to the tank (new fuels don't work too well with the early confirmations) works great. 
I had to figure out what cables I needed between the two batteries and from the alt and to the rest of the system. But given infinite time and money and patience and did I mention time, money and patience? All has worked out. So far.

 

It seems to me that if you have two 6V batteries connected in series that will be 12 V no matter where, but maybe you can show us how you made all your connections and switches and diodes and solenoids and transistors so we can do the same, lots of people want a 6V / 12V car including me.

[drovak]

I would be concerned that there's nothing to balance the batteries, but maybe it doesn't matter so much with lead acid. 

[BuickTom87]

For my 32 and 29 , what I’m going to do have a box made to support it in the factory location with better support . 

[drovak]

I was referring to electrical balancing of the cells, rather than the mechanical consideration. 

[Barney Eaton]

Those short double ended cables are used on electric golf carts and should be an easy find on Ebay or other places. 

i never had a problem on my 320 Buick with one Optuma ... the question I would have  using 2 batteries is could the charger overcharge

one ...I don't understand electronics enough 

[edinmass]

If you need custom battery cables…..long or short, go to Brillman as they make anything you need overnight, at very reasonable prices. Since I run two optima batteries in all our cars except our Auburn, they have made me a bunch of special order cables.

[Skidplate]

Ok so to start, I'll try to explain a few electrical facts. And this may be a little difficult without a drawing or two but let's give it a go.
Let's say you have 2 identical 6v optima batteries that you've connected in series, I.e., the positive side of one battery is connected to the negative side of the other and neither battery is connected to anything else, just to themselves. If each battery produces 6v then using a multimeter and checking from the far end of the first battery (the negative terminal) to the far end of the other (the positive terminal) you will read approximately 12v. If you then connect that negative terminal to your vehicles chassis and you connect the positive terminal to a working 12v alternator and start the car, both batteries will get equal share of that 12v source. As in, the first battery will see the entire 12v but because the negative terminal of that battery is actually 6v away (because it's NOT the battery connected to the chassis), it only sees 6v. And likewise because the second battery is 6v away from the 12v source, it too only sees 6v. A typical 12v alternator produces maybe 14 or so volts, the first battery gets around 7v which will keep it charged properly and the second battery gets 7v too.
Remember, this all only works as long as the two batteries are connected together. You put 12v on a 6v battery that is connected to ground then all bets are OFF.

Does all that make sense?

Edited December 12, 2023 by Skidplate (see edit history)

[Skidplate]

So then, at the risk of kinda oversimplifying things, you buy two 12v high current relays (I'm thinking I used something like 50amp relays to be really safe) and a fuse box for everything that you want to use 12v. Connect one of the relays between the 12v terminal and to the 12v fuse box. Connect the other relay between the 6v terminal and to your original 6v circuitry. That will satisfy the original 6v requirements.
You connect a separate wire from the 12v terminal to your original ignition switch removing the original 6v wire from that switch. You connect the output of that switch to both high current relays (relays have 4connections. Input voltage from terminal. Output voltage to the load bank of choice. 12v from the ignition switch. Connection to ground) and those two relays will feed both systems 6v and 12v.
Sounds like a big deal but it's a lot easier than rebuilding all your gauges. You can choose what to keep 6v and if and when you wish to upgrade certain components to 12v, you already have everything installed. I wired my headlights to 12v and changed to equivalent 12v bulbs and they now rock and role. Purest be damned.

And finally I'll say this. If you ARE a purist and want to keep everything vintage original then I apologize for wasting your time. If however you want to truly drive your car into a substantial part of this century, upgrades of some kinds are inevitable. Now I've said it, and let the shouting begin. Cheers

Edited December 12, 2023 by Skidplate (see edit history)

[Barney Eaton]

can you put that in a schematic?

i might be able to understand 

[Skidplate]

I can I suppose. Give me a day or two.

[Hubert_25-25]

The reason that I use the special cables (see my earlier post) with the additional post on the terminal connection is that the contact area of this connection set up is large.  Using a 5/16 eyelet terminal end and the 5/16 bolt that clamps to the terminal is a rather small connection and would not pass as many amps.   The quality of the wire used in these jumpers is very high, but the connection lets it down.  

 

Edited December 12, 2023 by Hubert_25-25 (see edit history)

[Skidplate]

Sorry for helping hijack this post but it's such an interesting subject, it was bound to happen. So here's the schematic. My crayon wasn't very sharp but non the less. Not sure if it's going to be legible until I post it. I'll redo it if necessary.
Another note: if you have a 12v starter, you just pull that part of the schematic off of the 6v relay and onto the 12v. Ask if you have questions.

 

 

Edited December 12, 2023 by Skidplate (see edit history)

[Morgan Wright]

My head hurts.