Jumping (starting) A 4-wheeler With A Semi-truck

I recently helped a kid/teenager by jumping his car with my car. I hooked up the terminals/jumper cables myself. It was night, and I used a flash light to check the terminals. His mother was there, and she probably could have done it- she sounded knowledgeable.

Anyway- Does it work to jump a 4 wheeler with a truck? I'm thinking of the multiple batteries a truck has.

Another question- I would think liability would be a reason not to jump a 4 wheeler with a truck. Also could be a company policy.

My father has had a 4 wheeler battery blow up when jumping. This may be because of the old style battery which you could refill the fluid with water. I have never seen a blow up. Any comments on this?

Also I recently had to jump my Toyota. I was at a Walmart, it was cold, and my 6 year old battery would not start my car. I bought a new battery.

You could jump a 4-wheeler with a truck. Most diesel road service trucks (think AAA) have multiple batteries - they're all 12V systems.

Big trucks use multiple batteries - because the amps required to turn over one of these motors, because of the high compression of a diesel (15-23:1).

Much as we might want to be helpful - I don't know that I would want to risk the potential liability of doing so, though I can't speak as to whether there are "company policies" against doing so.

As far as batteries "blowing up", this could be due to old style (non-sealed) batteries venting explosive gasses (hydrogen), an internal short, or any number of defects.

Batteries go dead for a number of reasons - age, electrical issues in the vehicle itself, leaving accessories on, etc. - but again - with a company vehicle, I wouldn't want to be "that guy", that fries a strangers car electrical system during the "act of kindness" of just trying to be helpful.

Rick

I believe the truck batteries are wired in parallel, not in series, so that's why you still get the same 12v with multiple batteries, and why you can jump across "platforms."

I actually had a 4wheeler jump my truck once. I parked at a semi-remote rest area and forgot to turn off my headlights. The next morning the battery was deader than a doornail. There was a guy there in a construction-type dually work truck who kindly offered his "batterial services," and it worked like a charm!

My PSD trainer and I were at a truck stop and a Ford focus pulled up to the truck next to Us. The driver tried to jump his truck battery from a Ford focus. He went to the gas pumps and offered several drivers money to jump his truck.

My trainer walked over "guy...this ain't gonna work. You might want to walk over to the repair center and get them to help you out." The guy had no idea there was a service center there.

Even a Ford Focus will recharge Truck batteries (assuming they arn't Frozen), you might have to run the Focus at high Idle for a half hour to get enough Recharge Amps into the batteries,,,

The Dangerous thing about jumping a truck to a 4 wheeler is crossing the + and the negative cables,,, is always Bad. Things is truck batteries are 1000 AHs or more, and in Parallel which means you have over 3000 AMPs at 12 volts, I don't want to be there if some one hooks the cables up backwards.

As far as Blowing up batteries, every battery charger or jumper cable set comes with instructions about hooking up the Positive first, then hooking up the negative second AWAY from the battery, IE engine block or frame so you don't spark the Hydrogen

A couple things, batteries emit hydrogen gas, especially when charging, think Hindenburg. The key is to avoid creating sparks! Attach the red, positive cable clamp to the positive (+) battery terminal of the dead battery. You want a solid connection to the battery terminal, which may require some initial wiggling of the clamps Attach the red, positive cable clamp on the other side of the jumper cables to the functioning vehicle’s positive (+) battery terminal Connect the black, negative cable clamp to the working battery’s negative (-) battery terminal. Walk over to the vehicle with the dead battery. Do not connect the black, negative cable clamp to the dead battery. Instead, attach that clamp to an unpainted, metal part of the car such as a shiny, clean nut on the engine block. This will help ensure a safe jump, as any sparks you create here will NOT be near the dead battery. Any 12 volt system can jump start any other 12 volt system, but in the case of jumping a semi with a car you will need to run the car at a high idle to generate enough amps and you may need to wait a while to charge the semi's batteries because a semi trucks diesel takes more amps to start than a car. In the case of jumping a car with a semi, there will be plenty of amps to immediately start the car. Always use heavy gauge cables to avoid heat buildup in the cables potentially leading to melted insulation and subsequent sparking due to resistance, and always wear eye protection.

Phil