12v battery for 6V equipment

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Migo
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* REQUIRED* Type and Year of Model Ts owned: 1924 touring
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12v battery for 6V equipment

Post by Migo » Fri Nov 10, 2023 2:44 pm

Greetings to all of you!
I believe that i’ve not been here for 2 years or something.
This terrible war that Putin started against Ukraine makes me upset.
But Im still in Russia and trying to live the normal life anyway.

So my 6v battery fell in poor condition and a couple of weeks ago I was needed to ride and put 12v battery instead. Starter worked great (very fast) and dynamo indicated charging the battery.
What except lamps is to be replaced to change the voltage of the electric system?
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RajoRacer
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Re: 12v battery for 6V equipment

Post by RajoRacer » Fri Nov 10, 2023 4:26 pm

Greetings ! You might consider a starter converted to be operated at 12 volts or carry several Bendix drives & springs. The cut-out or regulator should also be exchanged.

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Humblej
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Re: 12v battery for 6V equipment

Post by Humblej » Fri Nov 10, 2023 4:47 pm

You are going to ruin your starter and bendix using a 12v battery. Best to replace with a 6v battery.


Lil Teezy
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Re: 12v battery for 6V equipment

Post by Lil Teezy » Fri Nov 10, 2023 11:24 pm

I use my T almost daily with no genny and no starter. You could change the headlight bulbs to 12v if you need them, disconnect the generator completely and hand crank to start on battery. recharge as necessary every few drives until time and parts for a more authentic solution are available- or don't...it might be a little slower and mileage will be somewhat limited and worse at night if you can't use the magneto. My cars mag doesn't work, but I usually go three or four days of crossing the valley back and forth without charging on just a 6v. The car will let you know when the voltage is low, misfiring at higher rpm or under load and the battery will wear out a little sooner than normal, but there will be no negative effect on the car in the long run and you can continue to cruise it in the meantime as long as you consider the limitations. Good luck! -Chris, in Boulder


Luke
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Re: 12v battery for 6V equipment

Post by Luke » Fri Nov 10, 2023 11:37 pm

Mikhail,

As Jeff has said 12V will be no good for an unmodified starter. However you can fix that without much expenditure - just take the starter out, dismantle it and rewire the field coils all in series (rather than series-parallel as they will be now). This will allow it to operate on 12V without damaging the rest of the mechanism. There are explanations of how to do that on here.

Alternatively Chris makes a good point, I also ran my T without a starter or generator quite successfully. They will run for quite a while on a battery (or indefinitely on mag :)

Otherwise just the bulbs will need changing, and perhaps drop the charging current back if it's too high - somewhere around 2A to say 6A would be best; the least you actually need. The reason for this is that while the generator will happily charge at 12V it will be double the power (assuming the charging current remains the same), and they have limited capacity to cope with that.

Great picture by the way!

Luke.

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dykker5502
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Re: 12v battery for 6V equipment

Post by dykker5502 » Sat Nov 11, 2023 7:05 am

Generator is a 100W unit regardles of voltage, så max 7A and as low as you need to keep it happy with lights on.
Ford Model T 1914 Touring
Ford Model T 1921 Roadster Pick-up
Ford Model T 1922 Fordor (danish build body)
ECCT, Strobospark, HCCT(Sold), Rebuilding coils

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Rata Road
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Re: 12v battery for 6V equipment

Post by Rata Road » Sat Nov 11, 2023 5:50 pm

My experience is the opposite to most.
My first T came with a 12v battery and standard starter. People all said carry extra Bendix springs etc.
Car has been 9 years at least on 12v and never broken a bendix spring plus it has a Z head and the compressions are very high, 80 - 90 psi.
Just make sure you set the lever correct every time you start it.
I have recently purchased a 1914 which has a starter and has been 12v for 17 years with no issues. It broke its Bendix last weekend. Its only a 20 minute job to replace.

We have a tourist Model T railcar in the district that volunteers drive on the weekend which is on 12v. Due to untrained drivers historically this broke a bendix spring several times a season. The auto sparkie that used to replace these all the time fitted a bendix spring on top of the starter to reduce the load from the 12v coming in and it has NEVER broken a bendix spring for years so I believe this method works.
I have now fitted a bendix to the top of my both of my 12v cars.
Its a real simple job to fit.
I have never carried a spare bendix spring in any of my T's.
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speedytinc
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Re: 12v battery for 6V equipment

Post by speedytinc » Sat Nov 11, 2023 6:07 pm

You have been lucky.
That bendix spring atop the starter doesnt limit the engagement bang.
It will lower the cranking speed.
Exactly opposite what is needed for a 12V battery on a T starter.

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RajoRacer
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Re: 12v battery for 6V equipment

Post by RajoRacer » Sat Nov 11, 2023 7:28 pm

And - DON'T touch that spring after attempting a start !!!!!!!!


Luke
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Re: 12v battery for 6V equipment

Post by Luke » Sat Nov 11, 2023 11:58 pm

Absolutely what John said.

Attempting to use a bendix spring as some sort of low-ohm resistor is not a good idea. Steve, I don't doubt you may have had a good run since but coincidences do happen. Much better to use a little solder and a short length of wire to series all the field coils (or replace with new 12V coils, but I guess these may be difficult to obtain in Russia right now) ...

Luke.

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Craig Leach
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Re: 12v battery for 6V equipment

Post by Craig Leach » Sun Nov 12, 2023 1:09 am

I went to 12 vdc when I had a 6 volt battery fail & was unable to purchase another where I was @. Changed the brake light bulb to a 12 volt
& ran the event with no issue. Changed the headlight bulbs & have run 12 volt ever since. My speedster is lowered so far that the front axle
covers the starter hole so there is no way to hand crank it. I replace the Bendix spring, bolts & key every year. After 16 years I have not had
a failure. I carry the old spring, bolts & key with me just in case but have always given them to someone that had a issue (6 or 12 volt) My other
T is hand cranked 90% of the time so I replace those parts every 2-3 years. I do use the lowest cranking amp battery I can find (no Optima's
anymore ) they are hard on low currant charging systems because of there resistance to charging & have way more cranking amps than needed
to turn a stock T starter. A 240 CCA lawn mower battery will turn a T starter very well & will charge backup in short order. If you can change the
starter wiring that is better. Craig.


Topic author
Migo
Posts: 16
Joined: Wed Apr 24, 2019 6:02 am
First Name: Mikhail
Last Name: Gotesman
* REQUIRED* Type and Year of Model Ts owned: 1924 touring
Location: Tula
Board Member Since: 2011

Re: 12v battery for 6V equipment

Post by Migo » Tue Nov 14, 2023 4:31 am

Thanks to everyone for the answers. Will buy 6v battery and keep the original system :)

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