[Coleshan]

Hey guys I need some help,

I got a Basically brand new battery (11-21), continuously dying on me…. I boosted the car yesterday and drove it abit to charge the battery, then shut it off, waited abit and it started back up fine. I then unplugged the IBS & Erased the codes and parked it for the night.

Came back to the car today , tried starting it and it was completely dead again….

Also checked if car goes to sleep, and 5 mins after locking the car the P on the shifter disappears so it does indeed go into sleep mode…

Any ideas? I heard some say it could be the IBS, voltage regulator on the alternator, or alternator itself, I’m doubtful of this though…

Side note, there is a wire in the trunk that is not connected to anything, does anybody else have this wire? If so what’s it connected to? I took it to a shop a while back and mentioned that wire, they stated that it’s aftermarket, again I’m doubtful of that statement though...

Attached is screenshot of the battery related codes it’s throwing.

Could a bad TPMS antenna cause a battery drain? I’m pretty sure I have a bad antenna on top of this issue.

Please help LOL , don’t wanna take it to a shop if I don’t have to…

 

[kd7iwp]

I've always worked on these issues in one of two ways. Many people have an electrical multi-meter and if it measures current you can hook it in series with the battery (provided no more than 10 amps is being pulled which is the typical allowed on most multi-meters) and pull fuses until the current drops. I've also sometimes seen people use a thermal camera to look at the fuses and look for any that have a slight temperature variation when the vehicle is off, I recognize most people don't have thermal cameras.

 

[Coleshan]

Thank you for your response, I have a voltmeter & will attempt this tonight. However, I am not very experienced with the voltmeter & am unsure even which setting to put it to and which slots to insert the prongs as their is 2 prongs with 3 slots on the voltmeter.

 

[mattmar1]

when testing for a parasitic draw, open the trunk and glove box, thats where the fuses are and passenger door. allow the car to fully go to sleep (trunk light and "P" on shift console off) . with this method youre just using the "common" (black) and the voltage slots on your meter, not the "A or AMPS" connection, dc voltage (it probably has a solid horizontal line above a dotted line) and the lowest voltage setting, youre looking for millivolts (thousands of a volt). you dont want to open/close anything to avoid waking the car up. one thing i dont care for in the method of monitoring the current being drawn is that the car can be woken up whilst pulling fuses, doesnt apply to all models, use whichever method youre comfortable with. though it takes more time, this is the method i prefer and has worked well for me.

parasitic draw test voltage drop - Google Search

 

[kd7iwp]

That voltage drop test seems far superior to the one I had suggested checking for current draw. Thanks for the suggestion @mattmar1

 

[mattmar1]

always glad to share and learn on here, ive learned a lot from you and others....im an e39 guy

 

[habbyguy]

Define "drove it abit". I've found that driving around a couple minutes isn't enough to charge the battery enough to matter. If it was 10-15 minutes, that's different.

My personal favorite new tool (OK, one of them...) is the clamp-on multimeter with DC current capability (using the clamp - many do AC current only with the clamp, and DC with the leads). Better are those with remote reading (so you can use an app on your phone to monitor your current, with the trunk / hatch and hood shut). Here's the one I bought (no claim that it's the best deal out there now, of course). Really a nice addition to my tool chest for under $50. (this was copy/pasted from another battery thread currently running). This makes it dead easy to check current, as you just clamp the meter around the read lead(s) (or even the black ones) coming from the battery, and can shut and lock the car completely so it's in its "natural state" when sleeping.

 

[mattmar1]

id been looking at a different ac/dc amp clamp, just to have one cuz both my others are ac only. i like that one
and i like that it measures capacitance. ive a handheld cap meter, itd be nice to consolidate all 3 functions in one

 

[habbyguy]

The remote reading function is great, too. When I was chasing a parasitic drain problem, I just clamped the meter around the battery lead in the "trunk" (wagon), and would check it remotrely with my phone every 10-15 minutes. Couldn't ever catch the problem that way, since it turned out to be an intermittent short in the hatch glass release button that triggered randomly, turning on the interior lights - always when I wasn't there to notice. ;-)

 

[Mixedwarrior]

I had a similiar issue a few weeks ago, exactly every thing you are experiencing and it came down to the alternator, once I had a new alternator installed every issue and code disappeared.