Battery Life using coils

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Dennis_Brown
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Battery Life using coils

Post by Dennis_Brown » Mon Sep 27, 2021 8:44 pm

If I was to run a T motor using the 4 coils and a 12 volt battery, no generator and no mag, about how long would the battery last before needing recharging ? Then throw in LED headlights and tail-stop light and charge life would be reduced but reduced less if ran in daylight hours without headlights. Would it last 6-7 hours without using a starter?

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Humblej
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Re: Battery Life using coils

Post by Humblej » Mon Sep 27, 2021 9:00 pm

Best way to determine how long the battery will last is to measure the load of each electrical thing one at a time on your ammeter: coil; lights; etc. Batteries are rated for so many amp hours, divide the battery amp hours by the total load in amps, and you will get how many hours...that is on a healthy fully charged battery. You might figure a 5-8% reduction in amp hours for every year the battery is old.


Norman Kling
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Re: Battery Life using coils

Post by Norman Kling » Mon Sep 27, 2021 9:23 pm

Also depends on whether you use a starter or hand crank. And whether you drive with lights on. If only ignition, it will last very likely all day or at least until you can use a charger. If using the starter, you might drain it very fast.
Norm


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Re: Battery Life using coils

Post by Scott_Conger » Mon Sep 27, 2021 9:24 pm

If you are running a fully charged automotive style battery, the answer to your last question is: Yes
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DanTreace
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Re: Battery Life using coils

Post by DanTreace » Mon Sep 27, 2021 9:49 pm

Just keep that storage battery charged up.

Once ran out of juice in my '15 speedster, hand cranker, vibrator coils operating off 12v storage battery.

Thought it was charged. Nope, ran out of juice in 4 hrs. Had to hitch a ride carrying the battery to a station for a fast charge.

Henry was correct, his T with the flywheel magneto can't die on the side of the road for lack of juice, like my speedster. :o
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Re: Battery Life using coils

Post by speedytinc » Tue Sep 28, 2021 8:24 am

Back in the day, a fellow club member ran his 13 all day on a makita 9.6V battery. Carried a spare in case.


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Re: Battery Life using coils

Post by TXGOAT2 » Tue Sep 28, 2021 9:17 am

You'd probably be in the ball park if you allowed 1.5 amps for the ignition with a stock system in good adjustment, then multipy the battery amp hours rating by .7. Battery capacity is reduced in cold weather, and a battery more than a year old will have reduced capacity. It's best not to run batteries down beyond about 1/2 to 2/3 of their capacity.


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Re: Battery Life using coils

Post by R.V.Anderson » Tue Sep 28, 2021 10:15 am

You can always carry a pair of the square 6V lantern batteries under the seat. When needed, for ignition only, wire them together (+ of one to - of the other) and they will run the car very well for quite awhile. Unlike a storage battery, you don't have to worry about spilling acid under the seat. And, of course, if you don't happen to have a set handy, you can pick them up at any Sprawl Mart, Home Desperate, or hardware store.


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Re: Battery Life using coils

Post by browning » Tue Sep 28, 2021 12:54 pm

I have a mountain of Dewalt battery chargers for my power tools which have the capacity to charge 9.6, 12, or 18 volt batteries which I also have a good supply of. I separated the case of one of the chargers and soldered in a pair of wires which I routed through the case when I glued it back on. They terminate in a polarized plug which mates to another wire connected to my coil box. It is a simple matter to attach the charger to the car, insert a battery (choice of voltage) and drive away. Not sure how long the car would run on one battery powering the coils full time but it is really easy to carry multiple batteries under the seat and the charger will still work if unplugged from the car and plugged into a wall socket.

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Re: Battery Life using coils

Post by TRDxB2 » Tue Sep 28, 2021 1:08 pm

Dennis_Brown wrote:
Mon Sep 27, 2021 8:44 pm
If I was to run a T motor using the 4 coils and a 12 volt battery, no generator and no mag, about how long would the battery last before needing recharging ? Then throw in LED headlights and tail-stop light and charge life would be reduced but reduced less if ran in daylight hours without headlights. Would it last 6-7 hours without using a starter?
Not all vehicle batteries are designed the same. Some are for starting )Modern Cars (CCA spec) other s recharging over and over (golf carts , boats, casual use Reserve Capacity or Ah). A battery's ability to provide power to operate lights, coils etc depends on its Ah, amp hour, specification. NOT to be confused with Cold Crank Amps or Reserve Capacity, which is are measures for an entirely different context and calculation method. AND the load placed upon it as well as ambient temperature. https://www.mkbattery.com/blog/what-do- ... ut-battery. There are many different "ratings" to help sell car batteries designed for modern vehicles
Not all batteries have the same Ah rating so.... some averages
-12 volt motor cycle battery about 12 Ah.
-Optima 6v Red Top about 50 Ah.
- 6 volt lantern battery 5Ah
-6 volt Group 1 car battery 210Ah
So how long can you run on a battery. Ah / load in amps = Time in hours
OR approximately on a fully charged battery not being recharged
car battery 50Ah / 4 amps =12.5 hours
Lantern battery 5Ah / 1 amp = 5 hours
Last edited by TRDxB2 on Wed Sep 29, 2021 12:12 am, edited 1 time in total.
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Re: Battery Life using coils

Post by TXGOAT2 » Tue Sep 28, 2021 1:48 pm

What does a Model T ignition system actually draw in average amps running on a battery at 6, 8, 12 volts? I'd guess about 1 amp. Does engine speed matter much?


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Re: Battery Life using coils

Post by Allan » Tue Sep 28, 2021 7:44 pm

I have run my 1912 Chocolate van with a True fire on 12 volt for some 20 years now. I use a motor cycle battery in a pocket next to the fuel tank, under the seat. I can do a day and a half of city driving on one charge. I found out about the half day when I forgot to put it on the charger after one day!
This runs indicator lights and brake lights but no driving lights.

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Re: Battery Life using coils

Post by TXGOAT2 » Tue Sep 28, 2021 10:19 pm

In your case, carrying a second, LI type cycle battery as a reserve would probably get you through 3 days. They seem to hold a charge very well over time.

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