battery 101

[blue4r]

So my truck sat undriven for about 3 and a half weeks, I should have disconnected the battery terminals but I didnt. When I got back from my trip the batt was too weak to crank.No prob, I got a jump and figured the alternator would charge it back up during normal driving. So I drove around for a while, always leaving the motor running when I stoped for a short while, and also let the motor idle for about one and a half hors when I got home. less than 1 hour later, the batt was dead again.
Here is the $89 question: is there a point where the batt is too low for the alternator to charge it back up?Will shop charging bring it back up or is it toasted? With the motor running there are no charging system warnings on the dash.

 

[Qyota]

Idling will not charge your battery sufficiently (a spin on the highway above 2K RPM will, though). The best way to know if your battery can be charged is to have it load tested at a shop or auto parts store.

 

[xskydivingdudex]

if the battery continues to die the thzt means its time to get a new one... there is a point where it wont recharge properly and thus ull need to get a new one bc if not ull have to jump start almost everytime.

 

[Blitzkrieg]

Just remember that your alternator is NOT a battery charger. Spend the $50 or so a good one costs (that also has a 2 amp trickle with auto shutoff) and do it right.

You don't show your location, but if you are in the snow belt and the battery is discharged and froze, you get to buy a new battery. A dead battery will freeze and when that happens the plates get ruined.

That being said, if your battery discharged in 3 weeks you either have a parasitic drain or the battery is old and shot.

 

[blue4r]

Thanks for the replies.....and I think I'm about due for a new one anyways. The current one is pretty old, its one of those old skool lead acid "wet" types.
I am looking at getting an Exide battery, had one in my VW Golf for 8+ years, and I lived in Michigan!
I also did a little research and it seems those wet batteries dont do well when the vehicle sits for extended periods. Plus, I left my fancy aftermarket alarm/immobilizer activated, and that may have contributed to the battery's early (not really) death.
Thanks fellas.

 

[Maxil]

Thanks for the replies.....and I think I'm about due for a new one anyways. The current one is pretty old, its one of those old skool lead acid "wet" types.
I am looking at getting an Exide battery, had one in my VW Golf for 8+ years, and I lived in Michigan!
I also did a little research and it seems those wet batteries dont do well when the vehicle sits for extended periods. Plus, I left my fancy aftermarket alarm/immobilizer activated, and that may have contributed to the battery's early (not really) death.
Thanks fellas.

The other bad thing about car batteries is most are not deep cycle. Meaning, if you leave your lights on and drain it fully, you have really hurts the batteries life span. This may not be true of all car batteries, but most of them are like this. Last time I drained one, it only lasted a few more months but was still fairly new.

Maxil

 

[TheDurk]

The other bad thing about car batteries is most are not deep cycle. Meaning, if you leave your lights on and drain it fully, you have really hurts the batteries life span. This may not be true of all car batteries, but most of them are like this. Last time I drained one, it only lasted a few more months but was still fairly new.

Maxil

This goes double for a battery that is nearing the end of its life. Sounds like perfect storm. Excess drain from alarm + 3.5 weeks without running + older battery = extended full discharge. It probably won't recover. Overnight on a charger plus load test is the way to tell for sure. But if it had 6 years plus service life I'd just get a new one.