What the heck is killing my battery?

[Jon]

I've had the same issue repeatedly with three different "new" batteries. If I leave it sitting for more than a few hours, the battery barely wants to start the truck. If I've been driving around for a while, kill it to get gas or something quick, it starts up fine. None of my added on electronics are pulling any current with them turned off.

The only current draw that I have is coming from the white wire feeding the fuse box. It is drawing 0.03 amps. Is that just the ECU? Just for reference I turned on one of the dome lights and the draw increased to 0.55 amps. All of the fuses are pulling 0.03 amps or more. WTF? :doh:

I'm at a loss....

 

[D Farms]

Is it shorting on the hood?

 

[KidVermicious]

I had a parasitic draw around .25 once that would drain my battery in about ten hours, .03 amps isn't draining your battery. Questions - are you sure you've got your multimeter set for the correct range and it really is .03 amps and not .3? Or 3.0? And have you measured the voltage across the battery terminals when it's "drained" to verify it really is?

Silly questions, but from what you're describing it seems like that's the stage you're at.

 

[Jon]

After typing that out I decided to do an alternator check. My battery was reading 10.0V. This is an hour after I moved from the driveway into the garage. Don't know what it was before that after sitting for a few days.

With it running, battery only gets up to 13.8V (no accessories) Not the greatest. Supposed to be 14.2-14.7 right?

Checked neg side voltage drop from NEG bat terminal to alt case, engine block, and chassis ground. All good at 0.01. Supposed to be 0.05 or less right?

Checked pos side voltage drop from POS bat terminal to alternator stud. All good at 1.1. Supposed to be 3.0 or less right?

No CEL or bat light...

This is a Duralast alternator that I've had since 2010. If I need a new one, I'm just gonna do the upgrade to a bigger one. I have a few accessories.

 

[my92t4r]

Start your truck and disconnect the negative off the battery to see if your alt is good. If its good, truck should still be running, if it's bad then your truck will die immediately.

Of course you can bench test it too.

 

[MStudt]

I've been down this road before. Leaving your truck sit will kill your battery even if you start it once a week. Testing for a parasitic drain is very easy, and you only need a test light to do it. You need to loosen the negative cable first. You can clamp the test probe end to the ground bolt on the fender next to the battery. Then touch the probe point to the negative terminal and slide the negative cable off. Do this right after turning your truck off. If you have a parasitic drain the probe light will stay light to some degree. If you don't have one, the probe light will just about go out after 4-5 seconds.

 

[AZ4Running]

4 year old Duralast battery. Change it out its old and Duralast sucks.

 

[IBallEngineer]

After typing that out I decided to do an alternator check. My battery was reading 10.0V. This is an hour after I moved from the driveway into the garage. Don't know what it was before that after sitting for a few days.

With it running, battery only gets up to 13.8V (no accessories) Not the greatest. Supposed to be 14.2-14.7 right?

Checked neg side voltage drop from NEG bat terminal to alt case, engine block, and chassis ground. All good at 0.01. Supposed to be 0.05 or less right?

Checked pos side voltage drop from POS bat terminal to alternator stud. All good at 1.1. Supposed to be 3.0 or less right?

No CEL or bat light...

This is a Duralast alternator that I've had since 2010. If I need a new one, I'm just gonna do the upgrade to a bigger one. I have a few accessories.

OK, 10V is WAAAY Bad. 13.8 is bad but not terminal. Have you tested the battery?

I don't know how you are testing the current draw, but if the numbers you gave are accurate, it's your battery.

Don't EVER EVER disconnect the battery with the engine running. NOT EVER! It is not likely but the voltage regulator will try to max the charging due to low voltage and a spike could fry an ECM. Pulling the cable is an old way the ignorant monkeys used to try to check the alternator. If a battery was fully charged the engine wouldn't die, it's just not the way to test ANYTHING.

:doh:

 

[TheDurk]

OK, 10V is WAAAY Bad. 13.8 is bad but not terminal. Have you tested the battery?

I don't know how you are testing the current draw, but if the numbers you gave are accurate, it's your battery.

Don't EVER EVER disconnect the battery with the engine running. NOT EVER! It is not likely but the voltage regulator will try to max the charging due to low voltage and a spike could fry an ECM. Pulling the cable is an old way the ignorant monkeys used to try to check the alternator. If a battery was fully charged the engine wouldn't die, it's just not the way to test ANYTHING.

:doh:

It can also fry the voltage regulator as it freaks out trying to charge a battery that isn't there. It won't happen every time, so there are always people who say they do it with no problem. But it's not worth the risk. DON'T DO IT.

 

[Climber]

4 year old Duralast battery. Change it out its old and Duralast sucks.

He said duralast Alternator

 

[BamaDrewski]

I have had this identical issue. Mine came with a brand new Optima I had at the time. I disconnected the DRL (Daytime Running Lights) harness that sits inside the driver's side fender next to the battery. (Two gray plastic connectors). Once I did this, the problem was solved. If you have DRL on yours, try it. (Mine is a 2000 Toyota 4Runner LTD. Hope this helps!

 

[LittleCaesar]

Start with checking the alternator first at Autozone. Then report back.

 

[Jon]

I think I'm gonna get the alt checked. Both batteries are the Duralast Yellowtops, had Optima Yellow before that. Both batteries have been checked and verified "good" from Autozone, at least twice on each one. I bought the additional one since I plan to run duals at some point.

I was measuring the parasitic loss by disconnecting each of my additional accessories from the POS side and measuring the current between them and the POS terminal. 10amp setting, leads on meter switched appropriately, and my reading for that white wire is 0.03 with nothing turned on and all doors shut. It is a cheap digital meter.

 

[4Running Daily]

OK, 10V is WAAAY Bad. 13.8 is bad but not terminal. Have you tested the battery?

I don't know how you are testing the current draw, but if the numbers you gave are accurate, it's your battery.

Don't EVER EVER disconnect the battery with the engine running. NOT EVER! It is not likely but the voltage regulator will try to max the charging due to low voltage and a spike could fry an ECM. Pulling the cable is an old way the ignorant monkeys used to try to check the alternator. If a battery was fully charged the engine wouldn't die, it's just not the way to test ANYTHING.

:doh:

Aw man. My battery cable bounces off the battery all the time haha.

 

[IBallEngineer]

I think I'm gonna get the alt checked. Both batteries are the Duralast Yellowtops, had Optima Yellow before that. Both batteries have been checked and verified "good" from Autozone, at least twice on each one. I bought the additional one since I plan to run duals at some point.

I was measuring the parasitic loss by disconnecting each of my additional accessories from the POS side and measuring the current between them and the POS terminal. 10amp setting, leads on meter switched appropriately, and my reading for that white wire is 0.03 with nothing turned on and all doors shut. It is a cheap digital meter.

What additional accessories?

What white wire?

Can you just check the Battery cable to the battery post?

 

[TheDurk]

Q.e.d.

it can also fry the voltage regulator as it freaks out trying to charge a battery that isn't there. It won't happen every time, so there are always people who say they do it with no problem. but it's not worth the risk. Don't do it.

aw man. My battery cable bounces off the battery all the time haha.

 

[TdogT4R]

Just because an alternator is charging at 13.8v doesn't mean it has the amperage to charge the battery. I'd try loading up the electrical system, turning every stock accessory on and see if you can get a flicker from any lights. No, it's not a definitive test, but will at least give you an idea if you haven't had the alternator tested yet. Just my two cents.

 

[curtperry]

This may be a remote possibility, but I noticed you have a XRC8 winch. I have one as well and when my solenoid went bad my battery was dying constantly. I figured out a day or two later that it was a bad solenoid because one of it's terminals and the cable leading to it was burned out, indicating it was shorting out somehow.

Worth a check.

The solenoids one these winches are prone to failure anyway, good to have a look at them occasionally.

 

[BrianSD_42]

Did you ever have the BATTERY tested?

 

[davidch]

Thermal imaging

I've never tried this, but it seems to me it's so crazy it just might work.

1) Obtain for $30 on Amazon a Black & Decker TLD100 Thermal Leak Detector.

2) Remove the vehicle's battery and charge it.

3) Let the vehicle sit long enough so everything is the same temperature. Perhaps let it sit overnight and do steps 4-6 below at an hour before dawn, before the sun alters temperatures of various things.

4) Install the fully charged battery.

5) Go to work with your B&D TLD. If there's an electrical parasite on your vehicle that's as hungry as you claim, it's got to be putting off some heat.

6) Whack it.