12v ccamps with 6v starter

any advice on how many cold cranking amps should be used on a super c with a 12volt battery and a 6volt starter.

With the combination you stated, I really don't think that it matters. The 12 volt battery spins that 6 volt starter so much faster. What I would keep in mind is buy a battery that fits in the battery box. I believe the 22NF is the one that is close to the group 1 6 volt battery. That battery should have plenty of CCA, and it will fit in the battery box.

The general rule for sizing batteries is 2 CCA's per cubic inch.

In actuality, the smallest 12 Volt battery you're gonna find will be "bigger" than that!

If it is in good shape, it will spin fast enough & start at -25F with a 6 volt battery. Why go to 12?

this tractor came with a 12volt alternator and ballast resistor to coil

A while back my friend Bob M and I discussed this very issue. My thought was when using 12 volts on a 6 volt starter (since it spins so fast and engages harder anyway) to lessen such a hard shock on the starter drive (which can be a bit tough on them) you dont really want such a high CCA battery, say use a 500 versus a big heavy honkin 1000 like you would on a 12 volt system and a 12 volt starter. He thought use a big battery but maybe use slightly smaller gauge battery cables when applying 12 volts on a 6 votl starter to reduce some of the higher kick in torque which can be tough on drives.

THIS IS STRICTLY A GUESS AND A SOMEWHAT EDUCATED OPINION but on a Super C with a 6 volt starter Id say a 500 to maybe 650 CCA 12 volt battery will spin her as fast and long as you should ever need and in my opinion a big heavy honkin 1000 CCA is nottttttttttttt needed and could be real tough on a starter drive (Heck even a 500 CCA will cause her to enage fast n harder then normal and still spin real fast)

John T

Though just our experience, we have operated IH tractors 12v over 6, for 1/2 their lifetime with no drive issues at all. We could be lucky , but we usually are not that lucky. Jim

Jim, Ive had mostly the same (basically good) expreience here (more when I was a used tractor dealer) but did experience a few starter drive/gear problems on 12 over 6 tractors. I think you definitely increase the chances if you use a big heavy honkin 1000 CCA battery, but most conversions I came across had smaller (say 500 CCA) batteries which I still believe is best in this aplication ESPECIALLY on a smaller tractor.

Have a Happy New Year, hope we can meet up at a tractor show sometime and talk shop, as if we dont get enough of that here lol

I forget where youre located, Im planning an extended RV trip next summer out West to 8 Natl Parks

Ol John T in Indiana

I'm ditto with the rest on this one. I used a 12v battery on my IH90 Combine for years with no problems at all. That was before I found out I was supposed to change other things too.
It's kind of like when Walt said to Madge, "What's with this bran muffin for breakfast, where's my bacon and eggs."
Madge says, "Muffins are more healthy for you."
Walter relplies, " My grandfather had bacon and eggs for breakfast every day of his life and he lived to be 97 years old."
Madge, "Yes, but that was before they knew about cholesterol."

Dell

I really respect you rand Bob M's electrical advice but it seems to me the CCA should not affect the impact of the starter drive unless the higher CCA results in higher initial voltage to first spin the starter. What's your thinking here?

The idea of using small cables makes a lot of sense since the voltage will drop sharply as the the starter tries to ramp up its amps and soften the blow.

I have been inadvertently doing this for years since smaller cables are cheaper and more available and obviously are ok with a 12v system.

Just a thought. Has anyone ever tried wiring a big electrolytic capacitor in parallel with the
starter? It would require something with a lot
of capacity like a 3300 uf or more. But with that in the circuit, you would think it would
cause the voltage across the starter windings to build slower (instead of instantaneous) and let
the mechanism experience a "softer" engagement.

Good mornin Andy, thanks for the kind words.
Ive NEVER ran any actual experiments, but it just seems intuitive to me a higher CCA battery stores more energy (that parts a FACT) and when the starter is connected to it, it pumps out more initial amps into the starter and drops less voltage (over time verus amps) then say a smaller battery that stores less energy would.

I figure the bigger battery can and will deliver MORE AMPS to the starter then the smaller battery and hey, more amps and more volts yields more kick in torque right?????? and thats what can be tougher on starter drives and gears I think

The CCA rating has to do with how many amps the battery can deliver BEFORE DROPPING DOWN TO 12 - X volts. A higher CCA can deliver more amps without and before it drops down to 12 - X volts. Its the voltage drop that is used to determine how many amps it can deliver BEFORE OR WITHOUT dropping x amount of volts. The same amp load out of a big CCA battery will cause its voltage to drop less then the same amp load out of a smaller CCA battery right????????????

Its true either battery drops voltage the more amps it delivers, but the higher CCA can deliver more initial amps before its voltage drops to a certain threshold level then the smaller CCA battery can. The bigger battery can maintain more volts at the same amp delivery then the smaller battery whose volts drop more at the same amps

Heck now Im confused, what was your question lol

Maybe Bob or Bob M or Jim or JD can explain it better

John T

Mornin Gary, Wellllllllllllll without doing any calculations IT SEEMS TO ME IT WOULD TAKE ONE ENORMOUSSSSSSSSSSSSSSSS HIGH RATED CAPACITOR BANK, perhaps the giant ones you see up on power lines to offset the inductive reactance of the starter motor.

However, your thinking and theory has merit. When you initially switch an inductor (starter motor) into the circuit IT RESISTS ANY SUDDEN CURRENT CHANGE its initillay (time = 0 +) like an open circuit. However, a capacitor is sort of opposite, it RESISTS ANY SUDDEN VOLTAGE CHANGE, its initially (time = 0 + ) a short circuit.

If an inductor and capacitor are in paralell, the majority of the initial current goes to the capacitor (its initially a short circuit, later an open to DC) and then once its charged up, the current goes instead to the inductor (its initially an open but later more like a short subject to its DC resistance)

LOve sparky chat

John T

That's why I'm an ME and not an EE. Every time I see electricity there is something wrong (except for lights).

Do you remember the discussion a few years back when folks were arguing that a six volt starter would not last on 12v?

I have always believed that the horsepower required of the starter to spin the engine faster on 12v was not double, and the amps would actually be less than half the 6v requirement. My logic is that some of the energy goes into overcoming friction which is not proportional to speed, and some of it goes into compressing air, and you get some of that back even when the spark does not fire on the power stroke. So the starter does not really care about voltage (for a long life) but it is running a a lot less amps.

Which brings me to a question. Have you ever measured cranking amps on the same tractor with 6v and then with 12v to really see how the amps go down?

You're probably right, I didn't do any math to verify, just thought if you could make that motor take even an extra quarter second to get to max RPM, you're doing a lot to ease things. Even if you paint it IH red it's probably just not going to look right on the side of that tractor anyway.