MTFCA Forum

I plan on using an 8 volt battery on my '24 T. (It currently has a 7 year old 6 volt battery and needs to be replaced). Any issues? Any changes to the generator and/or starter? (The 8 volt battery was given to me).

Replace with 6v Optima, will out perform an 8v and last longer than any other 6v battery.

6V Optimas are the best!

I'll s\third the 6v Optima proposal. Just make sure it is tied down. Like any battery, movement and excessive vibration will be deleterious.

Allan from down under.

jaybee47 wrote: ↑

Wed Oct 04, 2023 12:28 am

I plan on using an 8 volt battery on my '24 T. (It currently has a 7 year old 6 volt battery and needs to be replaced). Any issues? Any changes to the generator and/or starter? (The 8 volt battery was given to me).

No issues.
Keep the generator charge rate @ the lower end. 4-5 amps. Every 6V thing is rated 6-8V. Brighter lights, etc.

I realize that this is not what Jay was inquiring about. But, will a stock Model T generator charge a 6V Optima? My trickle charger has separate settings for lead-acid and glass mat. I don't know what is different about the settings.

Thank you all for the valuable information.

For the 6 volt Optima battery , I used two battery boards underneath to support and lift battery in the carrier, 2/0 battery cables ( picture shows old braided negative) , split sections of gas hose , covered battery holding frame, to protect positive cable from grounding out, and got cast metal battery hold down from e-bay to fit and more importantly be retained by original Ford battery clamps. Later modifications to hold down were made to have hold down straight between front and rear clamps, and negative cable was replaced with a 2/0 negative cable.

There may be issues using an 8 v battery. Head light and tail light bulbs are usually 6-8 v, so those should be OK. I do not know about the generator or starter. I personally wouldnt modify the car just to use a free battery.

Hallo ,
Why are Negative Cables Braided , And is it neccessary ???
thank for your answer
Toon

I recently purchased a really nice computerized battery charger that automatically discerns whether you are charging a 6 volt or a 12 volt battery. You don’t need to flick any switches or anything. Just plug it in and connect the clamps to the proper posts and let it do its’ work. Do you think it can discern that it is charging an 8 volt battery and make the necessary adjustments? Jim Patrick

jiminbartow wrote: ↑

Wed Oct 04, 2023 9:46 am

I recently purchased a really nice computerized battery charger that automatically discerns whether you are charging a 6 volt or a 12 volt battery. You don’t need to flick any switches or anything. Just plug it in and connect the clamps to the proper posts and let it do its’ work. Do you think it can discern that it is charging an 8 volt battery and make the necessary adjustments? Jim Patrick


IMG_7933.jpeg

No it cant.
There are 8V battery tenders. I finally broke down & got one.
Charging with a 6/12 V charger is a bit tricky. if the battery goes dead, I use the 40 amp 6v charge. It will get to 6.5-7V.
Then use the low amp setting @ 12V for 20-30 minutes, then check.

There is a difference between flooded lead acid (regular)& glass mat (Optima) batteries when it comes to charging them. A glass mat battery
has a greater resitance to charging the lower the charge is. Case in point your conventional battery charger will not charge a dead or very low
Optima it will continualy trip the breaker because of that resistance. If you try to run a low Optima in your T it will work your generator like
a rented mule and may burn it up. That is why there are special chargers for Optimas. The common method of charging a Optima that has a
low charge is to hook it in parallel with flooded lead acid battery and charge both to keep the breaker in the charger from tripping. Don't get
me wrong I like Optima batteries I used two of them for years in my speedster with no generator. Untill the price went up & the quality went
down. Where do you find 8 Volt batteries none of the battery suppliers I commonly use carry them! I havn't used one in 50+ years.
Craig.

8V batteries have gotten harder to get over the last 40 years.
I get mine from interstate batteries.
They have 2 case sizes, but apparently are of the same part #. The smaller one of the 2 fits a T

You can get 8v batteries from golf cart service/dealerships. Golf carts with 48v systems commonly use them. Jim Patrick

Well, voltage is voltage. What about the cold cranking amp capacity in the eight volt batteries compared to the six volt battery conventional or even the Optima? .... In a 6 volt battery system, amperage is the more important factor.

I'd buy a good quality 6 volt battery and be sure your cables, generator, and engine grounds are good. An 8 volt battery will work in a T. Lights will burn brighter and burn out quicker. Generator will work harder and longer if not regulated. Starter would be OK. If you run a stock ignition system on 8-10 volts DC, the timer and points may not last as long as on magneto or 6 volts. A good 6 volt battery works great in a 6 volt system, and they are easier to find charging/maintaining devices for. An 8 volt battery on a T system that uses the stock generator will run at 8 to 10 volts with the engine running at road speed if the charge rate is set at 4 amps or so. Limit charging rate to the practical minimum.

An 8 volt battery will typicaly have smaller cells than a comparable size and quality 6 volt battery. That could limit cold cranking amps when used with a 6 volt starter. Actual current available to crank the starter might be less than with a 6 volt battery under some conditions. Current does the work, voltage pushes the current through the circuit. (So to speak)

I run an 8 volt in my '17 with an electric starter. No issues, runs very well.
BTW, neither Tractor Supply nor Interstate could get me one. Batteries Plus was about two days out. (the kid at Tractor Supply showed me what he was sure was am 8 volt, explaining that the new type 8 volts only had 3 caps instead of the usual 4. Kids say the cutest things.)

TXGOAT2 wrote: ↑

Wed Oct 04, 2023 2:16 pm

An 8 volt battery will typicaly have smaller cells than a comparable size and quality 6 volt battery. That could limit cold cranking amps when used with a 6 volt starter. Actual current available to crank the starter might be less than with a 6 volt battery under some conditions. Current does the work, voltage pushes the current through the circuit. (So to speak)

Oh dear!

Power is the result of I*E, which in turn may be affected by R. 'Cold cranking amps' is a somewhat nebulous energy source factor and may indeed be affected by cell design but necessarily cannot be by the starter.

I guess that as Jay has been given an 8V battery (hopefully for free he may as well use it, but to my mind there's not much reason to go that way from 6V as long as you have a low resistance path from battery to starter & generator etc, and your starter is in good condition. There are reasons, IMV, to go to 12V as I've stated in the past, but that's not the focus of this discussion.

FWIW I agree with the Optima comments (and would advise the use of a regulator with any replacement 6V battery) but the original question was around the use of the 8V battery; Jay, your starter should be ok with that, you may find it advisable to adjust the charging current a little, 6V bulbs will have a shorter life.

Luke.

They will run brighter, but carry spares.

Craig Leach wrote: ↑

Wed Oct 04, 2023 11:27 am

Where do you find 8 Volt batteries none of the battery suppliers I commonly use carry them! I havn't used one in 50+ years.
Craig.

Golf carts. They are wired 36 or 48v in series so 6 or 8 6v batteries. On the 48v you can run 6 8v instead of 8 6v saving the owner the cost of 2 batteries something costing a good bit.

Hi Chad,
I must have missed something, I'm somewhat familar with golf cart batteries. Didn't think they fit in a T battery box? pleae educate me.
Craig.

The 801 8 volt battery is the same size as the 6 volt that fits the T battery box.

I’ve run my present T nearly every day for seven years with conventional 6V batteries from Tractor Supply and original 6V starter and generator. Have had three batteries and luckily the last two were under warranty. Seems they don’t make them like they used to. Connecting them to a trickle charger at night every so often seems to keep them alive longer. I would consider an Optima but I like using the original battery box installation.

Craig, I was simply saying where they could be found. As we all know everything fits with the proper tools available.

My Grandpa put an Eight volt battery in our 1925 touring the generator and everything is stock but there are some light bulbs that act as resistors underneath the dash and it makes for quite a jumble of wires! Especially when you put in the coil box!

Mark Osterman wrote: ↑

Sat Oct 07, 2023 7:19 am

.... Have had three batteries and luckily the last two were under warranty. Seems they don’t make them like they used to....

Mark,

Are you using a regulator, or just a cutout?

Luke.

Thanks Frank,
I have not worked on a golf cart in a long time (I don't golf)
Chad,
I agree I can do that & it sounds like you can too, but some do not have the tools to redesign a car to fit a battery? And some would not if they
did.
Craig.

I have not been able to determine the equivalency between an 8V golf cart battery & an 8V car/tractor battery.
The car batteries rate 520 to 600+ CCA. I see the car batteries are around $70 cheaper. The car battery is a direct fit into a T.
Why use a golf cart battery?

I've been using 8v's for more than 15 years, my brother and his son own a battery shop as well, I have never been told that they are golf cart, car or a tractor battery but the 801 is one of the battery bank for a fork lift.

I like Mark Ostermans post. He has it right. Mine is exactly the same way. The secret is good wiring. I use a 6 volt store bought battery from Auto Zone, and have never had an issue. You don't need more voltage, you need a top notch electrical system.

The newer 6 volt batteries don’t always use the” Group 1 “ designation. And if you tell the sales person you want a group 1 6 volt battery they usually don’t know what group 1 means.

Changing times I guess.

Wires carry electricity on the outside surface of the metal, braided strands have more surface area than a solid piece would.

ABoer wrote: ↑

Wed Oct 04, 2023 9:44 am

Hallo ,
Why are Negative Cables Braided , And is it neccessary ???
thank for your answer
Toon

TheSpeedsterProject wrote: ↑

Sun Oct 15, 2023 5:55 pm

Wires carry electricity on the outside surface of the metal, braided strands have more surface area than a solid piece would.

ABoer wrote: ↑

Wed Oct 04, 2023 9:44 am

Hallo ,
Why are Negative Cables Braided , And is it neccessary ???
thank for your answer
Toon

The so called 'skin effect' only applies to high frequency currents; not DC. The negative cable does not need to be braided provided it has sufficient cross sectional area.

A golf cart or forklift battery would probably be a deep cycle type. They are built to deliver moderate current over a longer time period and to survive deeper discharge cycles than is typical in automotive service. That might not be the best choice for an automotive starting battery, which is expected to deliver heavy current for a short period of time, without deep discharge cycles.

TXGOAT2 wrote: ↑

Sun Oct 15, 2023 7:41 pm

A golf cart or forklift battery would probably be a deep cycle type. They are built to deliver moderate current over a longer time period and to survive deeper discharge cycles than is typical in automotive service. That might not be the best choice for an automotive starting battery, which is expected to deliver heavy current for a short period of time, without deep discharge cycles.

Thats part of my concern in comparison of the 2.
I didnt find a cold cranking amps rating on the golf cart battery.
& yet its quite a bit more expensive.

I don't know why many low voltage DC ground cables are flat braided style. Modern vehicles don't seem to have them. A bare, flat, braided cable would get rid of heart faster than a round one, but I've seen plenty of round ground cables on heavy duty applications.
Smaller, flat braided or tubular cable is sometimes used to ground hoods or fenders to get rid of RF interference.

Hallo Toon,
The flat braided ground cables are in cars normaly used to ground the motor to the chassis, they are nice and flexible so they are better where a lot of movement and vibration are present. When used on a T to ground the battery to the frame there is no need for the extra flex but it will work fine.
Hope this answers your question.

As for the 6Volt/8Volt dilemma, the higher voltage of the 8V battery will pose no problems for the electrics of the car, it is not that much higher that it will burn out lightbulbs on a large scale or do much damage to the starter, but the generator will have a hard job charging it,
If you are running a cut-out it will probably charge as the cut-out does not regulate voltage so it should be able to reach a voltage high enough to charge your battery,
If on the other hand you run a voltage regulator, the voltage regulator will not allow a voltage high enough to charge the 8V battery.
Something similar goes for the (Red Top)6V Optimas, the construction of the Optimas makes that they require a little higher voltage at a somewhat lower Amperage to charge than a regular lead-acid battery, so they take a little longer to charge while driving and they require the special Optima charger to charge fully on the bench or in the car when parked,
Hope this explains it all
Leo

You do not need an 8 Volt battery, even with a high compression head!

You only need a good ground cable, a correct set of 0 Gauge (AKA 1/0 Gauge) Battery cables, a good starter switch, and clean starter terminal.

You can adjust your generator to charge an 8 Volt or 12 Volt battery, but it would have to be set at a lower current level, like 7.5 Amps for 8 Volts or 6 Amps for 12 Volts.

Leo v. S
Thanks for your EXPLANATION .
Toon

A cutout should be adjusted to accommodate an 8 volt battery. Much easier to use a diode, which requires no adjustment.

Art Mirtes