MTFCA Forum

I would like to use a 12 volt battery with one of my Model T. I already made the change for the starter taht will allow me to use 12 volt. My other T work on 6 volt as well. Which 12 volt battery you recommended?

I believe that the 12 volt "yellow top" Optima is a good choice, because it is still an excellent "starting" battery, but if the battery will undergo repeated deep discharges instead of being continually "topped off", the yellow top is designed to be able to withstand many more deep discharges than the Optima "red top". If it is the yellow Optima or other one 12 Volt battery please provide me the number.


Kind regards,

I had a yellow top 12 volt gel Optima in my 1915 for about a dozen years until it finally crapped out last month. I wanted to go back to 6 volts on the 1915 T just for "fun" which I just did, but darn these Optimas are expensive, the 6 volt Optima gel cost me $220! The 6 volt is only half the size of the 12 volt. Keep in mind that you need a relatively new charger for the gel batteries. My old charger from about 1970 had to be replaced since it would not detect or charge the gels if they got too low on juice. People with old chargers will think the gel batteries are no good since they run down and won't recharge, but actually the charger can't "see" the run down gel battery unless you hook a couple up in series...weird.

I've used Odyssey batteries with great success in my experimental airplane and M38A1 Jeep. Much less expensive than Optimas.

FYI The Optima battery is not what it used to be.
https://www.jalopyjournal.com/forum/thr ... sa.270258/

If you have a generator or alternator, just use the least expensive one that will fit. If not, a deep cycle would seem the best, but I'd use a marine deep cycle that is about the size of the old group 1 batteries.

Hi Tim which model of Odyssey you suggested for a Model T?

On the 6 volt cars (the coupe and speedster) I use the 6 volt red top Optima battery. The 1914 Touring was built up for my daughter with a 12 volt system. We initially used a battery from a 1967 VW and it worked well. I have used the same style on several other customer cars and no complaints so far. I believe it is number 42. The great thing is that they are readily available at NAPA stores.

I get all my Optima batteries from Summit Racing. Good price and free shipping. If you are going to use continuous charge and discharge cycles, you may want to consider the Optima Blue Top marine staring/trolling series. If memory serves me correct, they put out 650 CCA which is more than enough to roll over most Model T's and power whatever electrical systems they have. For recharging I just hook them up to a Battery Tender Jr. and let it get trickled up to full charge. And yes, they work well on gel cells and SLA batteries as well.

I use a compact twelve volt battery for both of my '13s. They are about the same size as a Model T coil.

Thank you Gentlemen for all inputs. The 12 volts battery I'm looking for is for a car with a starter. Hope that help.

It seems to me that the best of both worlds would be to build a larger battery carrier and use 2 cheap 6volts in series. Tap the starter cable and horn wire off the first battery so the starter and horn gets 6volts. Tap the rest of the electrical system for lights, coils, and the charging circuit off the last battery so those circuits get 12volts and both batteries get charged.

Adam, that is an excellent idea, thanks!

I love the idea of 2 x 6 volts battery but I thought I will prefer keeping just one 12 volts instead of 2 x 6 volts.

I've used the Odyssey PC625 but the 680 and 925 are very popular. The number represents the initial cold cranking amps. Depends a bit on how much space you have to mount it.

If you don't have a generator, you can either charge it with smart charger between trips or use one of Fun Projects Hot shot chargers to charge it from the magneto. FWIW - you should be able to get a few days of starts from a single charge if you don't run the headlights from it for any extended time.

Shop around as prices vary widely.

Mario,

I use the cheap ones from Walmart, O'Reilly, etc. and have had great luck. Half the price, put on a charging every 6 months deep cycle, still going strong 7 years later. As others have stated, high dollar gel-cells are not what they use to be.

All the Best,

Hank

I carry a small solar panel mounted on a cooler on my running board when touring and put outside when in the garage. I get 6 to 8 years on a plain jane group 1 battery in my 26. Just need to keep any battery topped up when stored.

Ah yes, a battery thread !
A simple answer is the following :
The standard Model T generator will not deliver enough voltage to keep a modern battery fully charged, Optima and other gel batteries and modern 'Calcium' batteries need a fairly high voltage to accept a charge.
If you want your T to charge your battery you'll need to install an old fashioned Lead-Acid battery, they're cheap and available from most Farm equipment dealers.
If your T does not have to charge your battery, you can fit anything you like, but if you want to use your electric starter you'll need one with enough cold cranking capacity, that is often printed on the battery sticker as CCA or Cold Cranking Amperage with a number, you'll need a reasonable CCA of about 250 minimum to crank the low compression engine of a T.
As mentioned before here; if you decide to go for a modern gel type like Optima, you'll also need the appropriate charger that has enough Umpf to charge it.
Hope this helps !
Leo

When looking at batteries its clear there is a price break between wet, gel, and agm batteries. Each with their distinctive charging, discharging, motion, size, weight, and price rating.

To me the "best" battery would be something that balances all of these. Something that fits well in a stock T box without side terminals that may short out. I would like to see which batteries fit and then a comparison between these batteries with their positives and negatives whether it's cost, longevity, modifications needed, etc.

I am currently using an old age unknown Optima 6 volt battery in my two model T's.
While on my way out to get the paper this morning (in the dark) it occurred to me that a lantern battery might be a good source of 6 volts for running the coils in the 15. the 25 has a battery case to confine the battery.
The 15 being a crank start doesn't. As soon as my new to me carburetor arrives I am going to try it.

My "T" came with 12v when bought it it has a Duracell 26R from Sam's club. It has only been in the car since 2011 (feb) It seems to tolerate long periods without use and I haven't had to recharge it yet. It only has top post so I don't worry about a short out.