Quote:
Originally Posted by ajbrown
I have never had a problem .... <just kidding> 
Actually, I have never heard this and likely never would unless reading this forum. In fact I recently jumped my 2001 Altima as I would any car. Thanks for the insight, I will have to do some reading on the subject. |
The battery is your vehicles only electrical surge protection/shock absorber. When severely depleted the acid is in the plates and you have nothing but water in solution. Hence the term sulfation for batteries stored to long.
If you jump a vehicle with a depleted battery the excessive current can travel into any circuit that is now open. Pressure moves from high to low. So lets say the dead car has a battery with 2 volts left in it. The Key is left on, The door is open and the good neighbor say's , " OK Hit it" You just forecd his ALternator to full field and produce it's max volts and Amps. That car does not know its being used as a donnor jumper. So 100 amps and 15 volts travels to any darn path it can go in the dead vehicle.
KaaaaaaaaaaaBam. Because electricity travels the speed of sound. FAST. In a nano second damage can occur.
Now with a cart or lawn mower or old school classic equipment no big deal. They have mechanical switches and components that can take a surge a spike or ac current. volate spike. Heck wait till these new fuel injected Carts with computers get jimped and tampered with!
Today cars are all inputs modules and processors. Most people do not know that the gear selector is a computer module that collects and sends data to the main processor. You push lets say the Air Conditioner button and really your just sending a input to a computer asking for AC. The vehicle will tell you if you get it or not. All enabeling conditions must be met.
Bottom line a dead battery should be brought up to at least 11 volts before trying to crank over a engine or run electrical componts. It's best practice to use a jump pack not cables from another vehicle.
Now I'm really going to rock some minds here in TV. That Wally World battery charger and even some large chargers in shops from the 70's - 90's can send out damaging AC current. So while they are charging your car they are playing dangerous with computer modules. A computer hates AC current. Don't believe me go turn on your charger and set your DVOM to AC current. Anything over half a volt is not good.
Had a friend with a $$$ New Range Rover. Battery went dead at school. Good old Bob the building trades teachers said. " I'll help you man. That idiot Herv is just a tech guy as I wanted the car pushed in the shop and battery put on my safe charger.
He jumped it with his pickup truck. Then it got towed to Land Rover to have a new computer installed. Thousand dollars plus later ole Herv was right.
Ignorance can be fixed with education but stupidity takes great salesmanship.