I don't understand why you have to shut the engine off on the car. How could it fry either alternator? There's NO way it would fry the car's alternator, but it shouldn't hurt the ATV either because the ATV is only going to draw the amps that it needs from the car's battery or alternator. All because the car alternator puts out more amperage isn't going to hurt anything. That's like saying you can't jump a Geo Metro with a wimpy electrical system with a Ford F350 Powerstoke Diesel with twice the alternator. As long as both are 12 volts DC and you hook + to + and - to - you should be fine either way.

 

just buy a charger!!!!!!!

 

"I don't understand why you have to shut the engine off on the car. How could it fry either alternator? There's NO way it would fry the car's alternator, but it shouldn't hurt the ATV either because the ATV is only going to draw the amps that it needs from the car's battery or alternator. All because the car alternator puts out more amperage isn't going to hurt anything. That's like saying you can't jump a Geo Metro with a wimpy electrical system with a Ford F350 Powerstoke Diesel with twice the alternator. As long as both are 12 volts DC and you hook + to + and - to - you should be fine either way. "

The reason is the alternator will go to full charge because the battery is dead. New alternators are not that robust.
Now an automotive alternator is not likely to burn up trying to charge a amall ATV battery.
This is the reason parts stores won't warantee alternators unless you test your battery to see if it is fully charged.

 

not to mention all the electronics now on newer cars...there are lots of weird things you cant do or you will fry the ecm

 

From an electrical engineer with 25 years experience and 30+ years experience with automotive and motorcycle repair... It does not matter if the truck's engine is running or not. The difference between jumping with 12 or 14 volts is minimal.\

What you don't want to do is try to start your quad with a car battery that is way under charged. Once started, the quads charging system will try to charge the large capacity car battery at a much higher current rate than the quad's stator and rectifier regulator was designed to handle, leading to possible damage.

 

Im going to switch the two.
Say your driving home from wheeling and your car battery dies, Can you jump the dead battery in your car with your 4 wheeler?

 

It is certainly possible to do. However, if the auto battery's charge is low enough, the current the quad will supply may be enough to damage the quads battery and/or charging system.

Although it is not likely to cause damage to modern motorcycle electronics, jumping the bike from running car does have one danger: If the auto is running it's regulator is trying to hold the battery voltage fixed at something around 13.5 to 14 VDC. No problem for the quad when it's not running. However, once the quad is successfully started, it too has a charging system who's regulator is trying to hold the battery voltage at around 13.5 to 14 vDC... here's the problem: these two charging systems will now try to fight each other, if the regulator's set voltages are not exactly the same (very unlikely that they would be). SO, the system that can source or sink more current (the car's) will win, and the quad's regulater will be trying real hard to control what it can't, causing it to overheat. Over too long a time, this can damage the quad's regulator, rectifiers or stator.

So, jump your quad from a car or truck, running or not, but once you get it started, immediately remove the jumper connection.

Hope that helps.

 

once again.just buy a charger...black and decker has some great models..for a reasonable price..they are vert high tech now..not just a big transformer and diodes anymore

this is a great one
http://www.blackanddecker.com/...s.aspx?ProductID=15578

 

Yes, buy a charger for use at home to maintain the battery. BUt, once again, If needed when in the field (as originally asked), follow my cautiions about jumping and you're good to go.

 

THATS WHAT INVERTERS ARE FOR..LOL