Battery's Keep Dying

[TerminatorCobraJP]

I can't figure out what the problem is with this car. I had initially got a dead battery, so I put a new battery in it. That new battery then died, so put a new alternator in the car and had the battery recharged, it died again. So I got ANOTHER new battery, it is now dead. I can't figure it out. Brand new alternator, brand new batteries just keep draining. I am 100% sure nothing is being left on in the car that could be draining it. What could be causing this? When installing the new alternator I slightly damaged that little plug in on the bottom of the alternator, could this plug potentially being damaged cause the alternator to just not charge the battery?

Sent from my SM-S536DL using the svtperformance.com mobile app

 

[DSG2003Mach1]

under what conditions is the battery dying? IE are you leaving it sitting in the garage for 48 hours and it's dead or do you go the store, come out and it's dead?

If it sits for some period of time you have a draw somewhere, there are some threads and guides on diagnosing parasitic draws using a volt meter. My car has always killed the battery in a couple days, I just keep it on a battery tender because Im too lazy to hunt it down

 

[TerminatorCobraJP]

under what conditions is the battery dying? IE are you leaving it sitting in the garage for 48 hours and it's dead or do you go the store, come out and it's dead?

If it sits for some period of time you have a draw somewhere, there are some threads and guides on diagnosing parasitic draws using a volt meter. My car has always killed the battery in a couple days, I just keep it on a battery tender because Im too lazy to hunt it down

I'll drive it for like a couple of weeks and then I'll go to drive it again one day and it has no power. The car won't even try to crank, no lights come on, key fob doesn't work. Could this problem have an affect on my idle? Since this has been going on I've thought the idle has seemed a bit lower than it should be, would a dying battery cause this?

Sent from my SM-S536DL using the svtperformance.com mobile app

 

[MG0h3]

Well first let’s get you a voltmeter.

You can get a $40 one at Oreilleys that will do damn near everything my $500 snap on one will.

First step. Verify you are charging.

This isn’t killing your battery but since you changed it and possibly damaged the plug, let’s verify.

13.8-14.2V at idle is fine.

Moving on, checking for a draw.

Disconnect the negative terminal from the battery.

Ensure the doors are closed. Key is out. Windows down is fine.

Hook one lead of the meter to the neg batt cable and one lead to the post.

The meter will be what all power draw on the battery is going through. There’s typically a 2amp and 10amp selection and lead ports. The 10amp won’t read as low, but it’s fused higher obviously. Use that one to start. If it’s under 2A, switch down the the 2a setting and move the lead to the correct port.

You really want to be down below 100ma.

You pull fuses while this is all in place to determine which circuit is drawing power.


Sent from my iPhone using svtperformance.com

 

[TerminatorCobraJP]

Well first let’s get you a voltmeter.

You can get a $40 one at Oreilleys that will do damn near everything my $500 snap on one will.

First step. Verify you are charging.

This isn’t killing your battery but since you changed it and possibly damaged the plug, let’s verify.

13.8-14.2V at idle is fine.

Moving on, checking for a draw.

Disconnect the negative terminal from the battery.

Ensure the doors are closed. Key is out. Windows down is fine.

Hook one lead of the meter to the neg batt cable and one lead to the post.

The meter will be what all power draw on the battery is going through. There’s typically a 2amp and 10amp selection and lead ports. The 10amp won’t read as low, but it’s fused higher obviously. Use that one to start. If it’s under 2A, switch down the the 2a setting and move the lead to the correct port.

You really want to be down below 100ma.

You pull fuses while this is all in place to determine which circuit is drawing power.


Sent from my iPhone using svtperformance.com

Thank you for the detailed response, I'll try to get started on chasing down my problem. So if the battery isn't charging in those ranges at idle that automatically tells me to look to the alternator?

Sent from my SM-S536DL using the svtperformance.com mobile app

 

[2003RedfireVert]

Thank you for the detailed response, I'll try to get started on chasing down my problem. So if the battery isn't charging in those ranges at idle that automatically tells me to look to the alternator?

Sent from my SM-S536DL using the svtperformance.com mobile app

Yes…maybe…if your plug is damaged going to your alternator than the alternator may not be getting the signal from the ECM to charge. I have a feeling you probably have a draw killing the battery. If you can drive it and it won’t die on you driving it around than the alt is charging just fine.

 

[Bullitt1448]

Sure sounds like a draw on the battery to me

 

[shurur]

I think the GEM module takes a few minutes to shut down after you close the doors, so you have to watch for that to happen before you go hunting the for the offending block.

There are quite a few threads about this.

 

[Bullitt1448]

Chasing a battery draw can be very simple or very frustrating. At work an electrical issue can be 10 minutes or 10 hours, you never know till you start

 

[TerminatorCobraJP]

Yes…maybe…if your plug is damaged going to your alternator than the alternator may not be getting the signal from the ECM to charge. I have a feeling you probably have a draw killing the battery. If you can drive it and it won’t die on you driving it around than the alt is charging just fine.

When it's running it'll drive around without dying but it feels like the car is on the verge of dying at idle. The car only likes to idle around 500 RPM, I don't know if that's related to this charging issue or something totally different.

Sent from my SM-S536DL using the svtperformance.com mobile app

 

[TerminatorCobraJP]

Something else that might be worth noting. Anytime I do something like roll the windows up or down, or put the top down the idle will drop and the headlights/interior lights will dim.

Sent from my SM-S536DL using the svtperformance.com mobile app

 

[Relaxed Chaos]

I had a series of 4 bad batteries in a row in one of my cars. #5 was a winner and has been working for a couple years now. Frustration and confusion were constant.

Improbable? Yes. Impossible? No.

I just had a $350 AGM crap out in 7 months.

Strange things happen under low voltage. Buy a lithium ion jump pack to make sure it'll start when the battery dies.

 

[TerminatorCobraJP]

I had a series of 4 bad batteries in a row in one of my cars. #5 was a winner and has been working for a couple years now.

Improbable? Yes. Impossible? No.

I just had a $350 AGM crap out it 7 months.

If I'm some how just getting bad batteries over and over again that would be a miracle. What are the odds of that?

Sent from my SM-S536DL using the svtperformance.com mobile app

 

[DSG2003Mach1]

500 rpm sounds a little low, at that rpm alternator output is probably way down

 

[Relaxed Chaos]

If I'm some how just getting bad batteries over and over again that would be a miracle. What are the odds of that?

Sent from my SM-S536DL using the svtperformance.com mobile app

I went through the same damn thought process!

Buy a jump pack so you can jump yourself when needed.

 

[kreymis]

I had the same problem. It was my factory Mach 460 amps. Pull the fuse under the dash for the amps and see if it still happens. Worth a shot


Sent from my iPhone using svtperformance.com

 

[TerminatorCobraJP]

Update: Went and got another new battery because I couldn't get the old one to jump start anymore. Picked up a multi-tester, and a new negative post terminal because the old one was a bit loose. They also tested the battery and alternator while I was there, getting over 14 volts off the battery at idle. So now I guess I start trying to find a draw somewhere.

Sent from my SM-S536DL using the svtperformance.com mobile app

 

[MG0h3]

Update: Went and got another new battery because I couldn't get the old one to jump start anymore. Picked up a multi-tester, and a new negative post terminal because the old one was a bit loose. They also tested the battery and alternator while I was there, getting over 14 volts off the battery at idle. So now I guess I start trying to find a draw somewhere.

Sent from my SM-S536DL using the svtperformance.com mobile app

Referring back to the question about the alt charging/not charging the battery meaning alt is automatically bad: no.

Could easily be a circuit problem (cables between alt/batt or as mentioned, wires on back of alt).

Sounds like you’re good to go on the charging front though so that’s good.

You either have a massive draw or a circuit/connection problem to the starter is possible as well.

When it won’t start is the battery like dead dead as in remote locks won’t work, no dash lights with the key on, or is it just a no crank situation?

Don’t want to get too much in the weeds here, but with low load like sitting at idle, you may see the proper charging voltage.

Add in some load like lights, brake lights, then roll the windows up, you’ve increased the load or demand on the system. A poor connection can rear it’s head in this situation. Cranking is the highest load you’ll put on the battery and the cables/connections at the battery.

But I’m guessing it starts for a day or two and then you’re tits up so the connections are likely fine.

I’d def start with that draw test I outlined above.


Sent from my iPhone using the svtperformance.com mobile app

 

[TerminatorCobraJP]

Referring back to the question about the alt charging/not charging the battery meaning alt is automatically bad: no.

Could easily be a circuit problem (cables between alt/batt or as mentioned, wires on back of alt).

Sounds like you’re good to go on the charging front though so that’s good.

You either have a massive draw or a circuit/connection problem to the starter is possible as well.

When it won’t start is the battery like dead dead as in remote locks won’t work, no dash lights with the key on, or is it just a no crank situation?

Don’t want to get too much in the weeds here, but with low load like sitting at idle, you may see the proper charging voltage.

Add in some load like lights, brake lights, then roll the windows up, you’ve increased the load or demand on the system. A poor connection can rear it’s head in this situation. Cranking is the highest load you’ll put on the battery and the cables/connections at the battery.

But I’m guessing it starts for a day or two and then you’re tits up so the connections are likely fine.

I’d def start with that draw test I outlined above.


Sent from my iPhone using the svtperformance.com mobile app

When the car doesn't start it is totally dead. Power locks don't work, no lights come on, the little button in the glove box won't pop the trunk. I notice the days just before the battery is totally dead the car will crank longer than normal on start up too. Going to try to do a draw test today, might not have enough time to fully test it all today though.

Sent from my SM-S536DL using the svtperformance.com mobile app

 

[MG0h3]

Sounds good man.

Curious how much it’s pulling.

Remember to start on the 10amp setting with the leads in the correct port.


Sent from my iPhone using svtperformance.com