luxury1

As I understand it, the alternator is responsible for charging the cars battery (among other things). Will it charge the battery all the way?

Also, why do batteries go dead if the alternator is always charging them up? Is it because the batteries eventually cannot hold a charge (kind of like cell phone batteries)?

RX469

iTrader: (1)

Yes, the alternator will or is supposed the battery, when the battery is fully charger it stops or does not over charge the battery.

Batteries eventually die because of many factors such as age, climate, type of use etc. and when they do they loose their ability to properly hold a charge. At this point it's not the alternator's fault, but the a possible defective battery to hold the charge.

eyezack87

iTrader: (4)

If your battery light is coming up, I'd replace it ASAP. I had to wait until my new license came in and the car nearly shut down on me when I was driving home on the freeway. You'll know when it starts to shut down because the radio will shut off, the ABS light will come on, and the interior lights start to dim.....

19psi

the alt. will charge a battery all teh way but it would take hours of driving at over 1500 rpm. alts. put out max amperage at 1500+ rpm. at idle they dn't put much out. so if you hvae a weak battery that you had to jump start, letting it sit at idle doesn't charge it much.
that's also why batteries go bad. they get weak but they never get charged fully by the alt because most people only drive a few miles to and from work each day.
you know how you're not supposed to partially charge your cell phone or video camera and then use it? same thing with a car battery.
google battery sulfation.

4TehNguyen

iTrader: (1)

replace a battery every 3-4 years regardless if its working or not, the one time it fails on you and leaves you stranded, it wasnt worth it. A tow will cost as much as a battery, not to mention the hassle, time lost, and safety issue of being stranded.

luxury1

I am going to buy one later this week! Thanks for all of the insight!

Koma

iTrader: (3)

Most modern cars have overcharge prevention built in but not all cars on the road do.

Only cars that I know of that disconnect the alternator after the battery is fully charged is BMWs, otherwise the alternator still is being run.