Battery or alternator, please settle this argument!?

Question

When my husband went to his car today it was dead as a Dodo! We jumped it off, and it drove fine, but when he tried to restart it , it was flat as a witches t*t!

He said alternator, but I think battery, because the warning light never came on to say that the alternator wasn't charging. And. . . he had been down a very bumpy track and I believe that this may have damaged the lead in the battery ( whacking it about )

what do you think?

We havent got a voltmeter to test it at the moment.

My money is on it being the battery!

Answer 1

This happend to me recently.  If you start it up and carefully disconnect the battery leads, it will still run if the alternator is good. If the engine dies when the batt is disconnected, WhaLaa its the battery. Good luck :)

Answer 2

Have both tested at a parts store before spending good money for either one. Most parts stores will do it for free. Auto Zone and O'Reillys both do it. The odds are about even as to which one it could be but since the warning light for the alternator didn't come on I'd look at the battery first.

Answer 3

hmmm bumpy track.   I was once in a car that broke down because the bolt came off the alternator......

Answer 4

If it started with a jump, then failed to restart then it is the Battery - so you win!!!

The battery is not likely physically damamged - its just run it's life, and needs replacing!!!

Answer 5

Its unlikely to be the alternator. Car batteries are prone to sudden collapse, so my bet is its the battery.

Answer 6

well its not that hard to drive it to any shop or parts store but if the alternator is bad it wouldnt drive far .... with a good battery or bad but with a bad battery you can jumpit and it will so... id go with a bad battery  but first id check the cables to see if they are clean and tight which is where most problems a cur

Answer 7

jump it and drive it at any car shop that sells batterys...they will put a tester on it to see if its charging,,

Answer 8

it could be either one at this point ,take both off and take them to auto zone and they will check both of them for free then you can settle this one,there's no way to guess at it though,if i had to guess i couldn't  say for sure which it is because both will cause the same thing,battery would be most likely to go bad though,good luck.

Answer 9

my money is on the battery cables or the battery

Answer 10

On those basics and having to make a choice, I'd go for the battery too.

When a car is running most if not all of it's electrical needs are supplied by the alternator. Therefore if it continued to run the alternator was working. The battery's principle purpose is to start the car. Batteries do not last for ever and when they die they lose the ability to accept or retain a charge. If the car had run and then cut out unexpectedly after a short time (because the battery was supplying the electrical needs and had gone flat) then the alternator could be more suspect

Answer 11

if you are betting on the battery then you are more than likely correct.  after you jump your vehicle the car is basically running off the alternator, but when you have to start the car, its all on the battery and starter.

the best thing to do, take it out and get it tested at any parts store  if that would make him more comfortable.

if he went down a bumpy road CHECK those cables, make sure nothing came loose and such.

if it were me, id say battery

Answer 12

Hmmm, now then, my first instinct would be the alternator too, but as you so rightly mention, this could be what has happened with the battery.

If the 'plates' become damaged within the battery, and then the battery shorts itself out, then you could have won the bet!

good luck!

Answer 13

Battery. Buy a voltmeter, cheap digital one, as the needle ones don't give you an accurate reading.

Answer 14

Alternator for sure. If it was duff the car wouldnt run. You can start a car with a dead battery and the alternator will supply power to keep it running. If the battery is shot and wont accept any charge the next time you try to start it off the key it wont go.

Answer 15

alternator definatly.

Answer 16

Depending on the car,you can start the car and remove the battery cable when running,if it dies it's the alternator or a short in the system.Or you can remove the alternator and bring it to most auto parts stores and they will test it for you,some stores can test it in the car.