said by Juggernaut: said by theboz1419:
All a battery is used for is to start the car.
That's incorrect. A battery is also a power buffer, and used to supply a stable voltage, and current. Alternators fluctuate as demand from the battery is needed, or exceeded.
This. And with pretty much all cars since around ~2000 or so having a lot of engine functions electronically controlled, a weak battery and forcing these systems to rely more on the alternator can cause all kinds of issues. And for most vehicles if they sense a low battery voltage, they will adjust the alternator output accordingly to try and recover which can also exacerbate things.
As a personal anecdote, my mom's prior vehicle, a 2000 Durango, had some strange issues at one point especially concerning staying running after starting. It would crank and start fine with no struggle but after a second or so would outright die unless you kept the revs up and even then it would struggle some. Mind you this was with the 4.7L engine which was the first in the model to go to a distributorless ignition (ie: Coil-on-pack, driven directly by the ECU). Long story made short it was narrowed down to a combination of a weak battery and battery clamps deteriorated greatly (possibly causing the weak battery issue). After the clamps and battery were replaced, the problems completely vanished from that point forward.--
I swear, some people should have pace-makers installed to free up the resources. Breathing and heart beat taxes their whole system, all of their brain cells wasted on life support.-two bit brains, and the second bit is wasted on parity! ~head_spaz