Battery when running

[smithers_0990]

Im having an argument with a friend.
I say you dont need a battery to keep the car running when your driving, he says you do.

Im almost 100% sure you dont need it other than when you start your car.

Whos right?

Thanks, Bryan

 

[fastdrvr23]

From personal experience: If your battery dies while driving, the car will die as well. The only time I have ever been stranded somewhere was when the battery in my truck died. The alternator creates electricty, but only to charge the battery, not run all the electrical systems in the car. I guess... LOL. Hell, all I know is that it sucked walking ~11 miles in West Texas looking for a gas station because my battery went to s***.

 

[1sty]

THe car is only run off of the alternator when running unless you draw alot of juice in spike with audio. However the battery is the ground reference for the car. No battery no ground no electric flow.

 

[sttl013]

Hypothetically? you don't need a battery in the car once it's running. However, testing this theory isn't a wise choice. While an alternator creates power, and internal (in most cases) rectifiers convert that energy into DC so our car can actually use it, without the battery in place, you would probably damage most electrical devices in your car. Raw output from most alternators is so awful (spike/dip/spike/dip), and the battery is used to "smooth out" the voltage. Kinda like the biggest and greatest power filter you can have.

 

[Sir Nuke]

to add another kink in the works....its truely dependant on the particular car/truck/motorcycle whatever you are talking about....in SOME vehicles the excitation voltage for the altenator is supplied by the battery even with the car is running....thus if your battery dies...the alternator stops producing electricity...and your car will die as well.....cars that are self suffecient....well the battery can be mostly or about dead and after jumpstarting the car will run.....just don't turn it off or put any unnecessary electrical loads on it.....don't run your lights or your stereo if possible......

so....like I said....its dependent on how your electrical system is made.....so BOTH of you could be right...there is NO PAT answer to this question/argument you are having.

 

[cjstringer]

Once the car is running, you don't need a battery. Alternator does the work.
My EET degree comes in handy in the weirdest situations.

 

[rodslinger]

Once the car is running, you don't need a battery. Alternator does the work.
My EET degree comes in handy in the weirdest situations.

Not entirely true. Sir Nuke explained it pretty well. Some cars WILL shut off if you disconnect the battery. Another thing to note is the battery is also a big capacitor and filter to help absorb electrical noise from the alternator and ignition. Spikes from the A/C, accessories, etc.. can kill the alternator pretty quick if the car runs too long without a battery connected.

 

[Todd]

I dont know about the technical mumbo jumbo. but a friend of mine was having a problem driving his mustang home one day. It kept dieing on him while he was driving. The problem was that the wire connected to the battery was loose and he had to pull over and keep connecting it again untill he got home to tighten it up.