Jumping IH H tractor

[Rich J]

Can I jump my H tractor which is an original 6 volt system with my truck which is a 12 volt system and if so what is the proper procedure

 

[old]

Yes no and sort of. One should never hook a 12 volt battery to a 6 volt battery or it can/will blow up in your face. One can how ever go right to the starter and make it spin over but if the battery does not have enough power to make a spark it will be a waste of time. Or in other words if the battery is DEAD it will spin over but will not start.

 

[Janicholson]

Old is correct. There are Farmall H tractors that have bolted on starter terminals that come from a heavy starter switch, and some that have a saddle switch mounted on the starter. The saddle switch with pull or push rod activation do not allow access to the starter motor terminal. They would not be able to be jumped that way, as the terminal on the switch is going to the battery, and regulator, not directly to the starter motor windings. Jim

 

[John T]

I agree with the other fine gents. When I was a used tractor dealer attending a ton of auctions where they jump started tractors I saw many battery explosions caused by jumping a 6 volt battery with 12 volts *&^%$ and the safer way to do it is ONLY JUMP THE STARTER MOTOR where possible and hope the 6 volt battery has enough to power up the ignition if its a battery/coil ignition (if a magneto its not battery dependent). If its an electric solenoid controlled starter the big OUTPUT post on the solenoid leads direct to the starter motor similar to some mechanical push switches and some starters have the big terminal on the exterior easy to get to. If its a saddle mount push switch you cant get direct to the starter input button. My method was to first attach the jumper cables to the starter motor (or switch or solenoid output) and make the last jump to a clean paint free frame ground. Avoid connections or sparks near the battery especially its top where explosive gasses may be present. While the starter still turns the same direction regardless of polarity be careful when jumping say a Neg ground car/truck to a Pos ground tractor so you don't short a battery. This can be done safely.

John T

 

[BarnyardEngineering]

Most pre-1950 H's have magnetos and don't need battery power to produce spark.

Really, any battery can explode during a jump start, that is why there is a very specific procedure to hooking up for a jump start that puts you away from the battery being jumped when making the last connection. Of course nobody, myself included, follows the proper procedure.

Batteries produce hydrogen gas when being charged, and jumping a dead-dead battery puts a massive charge to the battery, creating a massive amount of hydrogen gas. Gas + spark = Hindenburg disaster.

I can't recommend it but I have gotten away with jumping directly from a 12V to a 6 V on numerous occasions, and I still have both my eyes and all my facial hair.

Really connecting a 12V battery to a 6V is no different than putting the battery charger on 100A rate.

One thing you can do to mitigate is to have the 12V jumping vehicle turned OFF so you're only jumping off battery voltage. Another thing is to use cheap lightweight jumper cables.

If you're going to do it, also do it QUICKLY. The less time the batteries are connected together, the less chance of explosion.

And for God's sake, wear SAFETY GLASSES if you insist on doing it.

Much safer to just put the battery charger on and let it do its thing...

 

[John T]

Regarding your statement "Really connecting a 12V battery to a 6V is no different than putting the battery charger on 100A rate."

With all due respect I have a somewhat different "opinion" and believe (no proof or warranty ONLY an opinion mind you) THERE IS A
DIFFERENCE.

If a 100 Amp rated "charger" was connected to a battery I for one doubt it can pump near as many amps (for X time) into a weak battery
(subject to load and its resistance) AS COMPARED TO HOW MANY AMPS A GOOD FULL CHARGED 12 VOLT 500 TO 1000 COLD CRANKING AMPS (CCA) BATTERY
COULD DELIVER over the same short time period. There is a lot of stored energy in a 12 volt 500 to 1000 Cold Cranking Amp rated battery as
compared to the instantaneous power an ONLY 100 Amp rated charger might deliver for a certain time. I just don't see a 100 Amp charger
having the capacity to deliver like 500 to 1000 Cold Cranking Amps over X short time period BUT I HAVE NO PROOF THATS ONLY ONE MANS
OPINION...

But hey each are entitled to their own opinion which I respect and expect the same in return. Mine is simply THERE IS A DIFFERENCE in what
a 100 Amp charger can deliver over x time versus what a good charged 12 volt 500 to 1000 CCA battery could.

I agree 100% one should use care and caution when jumping 12 volts to a 6 volt system and its safer to ONLY jump the starter motor instead
of the 6 volt battery

Pleasure sparky chatting with you, best wishes and God Bless. Lets see what opinion others may have if there's a difference or not ???

John T

 

[miangus]

Best to hook directly to the starter. Do not connect to battery and leave connected for a couple of minutes like you do when jumping 12 volt equipment. Connect and start. If it doesn't start disconnect while reviewing the situation. Like others said shut off charging vehicle.

 

[Bob M]

Hey John - Agree with you 100% (as usual!) My additional thoughts:

While not recommended, I have successfully jumped many 6 volt tractors from 12 volt cars, trucks and jump packs. And even once from a 24 volt 4020 (connected to just 1 of the 2 batteries to get 12 volts).

Key is to keep as far away from the 6 volt battery while jumping in the unlikely event it should explode. Make the final connection to a solid ground on the frame or engine of the 6 volt machine - expect a big spark when the connection is made.

ALSO......engage the starter switch on the 6 volt machine BEFORE making the jumper ground connection. Then disconnect it the instant the engine fires. Otherwise the 6 volt voltage regulator could be damaged as the engine comes up to speed.

 

[John T]

Thanks for your input my old sparky friend. While Ive seen several 6 volt batteries explode when jumped by a 12 volt battery I NEVER saw one explode by connecting to a battery charger .........

John T