Battery: parasitic drain

[Skrelnik]

I also posted on the other forum as I am desperately looking for a solution.

Hey everyone, I’ve got a parasitic battery drain issue on my 2016 Dodge Challenger Hellcat.

Here’s the journey so far:

The car sat for about a month due to winter and snow. When I tried starting it, the starter barely turned—no crank. Dead battery.

I attempted to recharge the original OEM battery, but it wouldn’t hold any charge at all. So I replaced it with an Odyssey AGM battery.

Now, after installing the new battery, and going for a nice long drive, the following morning the battery was dead.

I charged the battery up again, went for a long drive and let the car sit overnight. This time though, I disconnected the negative terminal before going to bed to see what would happen.

I confirmed that when the battery is disconnected (negative terminal off overnight), it holds charge fine.

Next, I suspected the RF hub may be the culprit so I pulled fuse 33 and let the car sit overnight, but the next morning the drain still happened.

I also disconnected the negative terminal and ran the multimeter in series, which showed around 4 milliamps, which is normal.

Next steps:

1) I’m planning to pull one fuse at a time overnight to isolate the circuit.

2) Check Alternator by charging battery, disconnecting the alternator and ketting sit overnight. Any advice on common parasitic culprits in Hellcats or tips for speeding up this process?

I have no major aftermarket parts on the car, just a Legmaker intake and some black badging.

Thanks in advance!

 

[1971demon]

I also posted on the other forum as I am desperately looking for a solution.

Hey everyone, I’ve got a parasitic battery drain issue on my 2016 Dodge Challenger Hellcat.

Here’s the journey so far:

The car sat for about a month due to winter and snow. When I tried starting it, the starter barely turned—no crank. Dead battery.

I attempted to recharge the original OEM battery, but it wouldn’t hold any charge at all. So I replaced it with an Odyssey AGM battery.

Now, after installing the new battery, and going for a nice long drive, the following morning the battery was dead.

I charged the battery up again, went for a long drive and let the car sit overnight. This time though, I disconnected the negative terminal before going to bed to see what would happen.

I confirmed that when the battery is disconnected (negative terminal off overnight), it holds charge fine.

Next, I suspected the RF hub may be the culprit so I pulled fuse 33 and let the car sit overnight, but the next morning the drain still happened.

I also disconnected the negative terminal and ran the multimeter in series, which showed around 4 milliamps, which is normal.

Next steps:

1) I’m planning to pull one fuse at a time overnight to isolate the circuit.

2) Check Alternator by charging battery, disconnecting the alternator and ketting sit overnight. Any advice on common parasitic culprits in Hellcats or tips for speeding up this process?

I have no major aftermarket parts on the car, just a Legmaker intake and some black badging.

Thanks in advance!

Sounds like pulling a different fuse every night might be a start...

 

[covidcommander]

Return the Odyssey and get the battery blickie recommended. Start there before spinning your wheels

 

[McLovin]

If it's draining your battery overnight, it's a pretty significant draw. If you are going to pull fuse by fuse, I'd start with fuse F22 (40 amp green) under the hood. It's the fuse for the intercooler pump.

I had a similar issue, and the pump would continue running after the car was shut off until the battery got down to something like 5 volts.

You could also see if you can hear the pump running after shutting off the car. It's quiet so it's tough to hear. Located behind the bumper on driver's side.

 

[vortecd]

Is anything plugged into the car or anything recently changed?

 

[Skrelnik]

If it's draining your battery overnight, it's a pretty significant draw. If you are going to pull fuse by fuse, I'd start with fuse F22 (40 amp green) under the hood. It's the fuse for the intercooler pump.

I had a similar issue, and the pump would continue running after the car was shut off until the battery got down to something like 5 volts.

You could also see if you can hear the pump running after shutting off the car. It's quiet so it's tough to hear. Located behind the bumper on driver's side.

Thanks for this.

Is anything plugged into the car or anything recently changed?

Nothing is plugged in...i recently removed the subwoofer as I dropped something down there, so I am going to check if I punched a wire when I reinstalled.

 

[Skrelnik]

Return the Odyssey and get the battery blickie recommended. Start there before spinning your wheels

I am not debating batteries, but I currently have two Odyssey batteries, and the one in my Wrangler TJ has four posts to power a lot of stuff. Been perfectly fine for 7 years. The one in my Mazda is fine as well.

Ill stick with companies that work well for me. Plus, we know the battery holds a charge if not connected. I can drive every day, but need to disconnect the negative terminal each time I stop driving. I will still get it load tested.

 

[BULL]

4 or 400 mA?

4 should not drain a battery and is very low compared to normal, 400 is high and might be a problem, while I don't have a tech manual in front of me, my best memory was 100-150 was normal??

Edit: fixed "Williams" to mA

 

[BULL]

Oops, autocorrect got me, fixed

 

[BULL]

I got tired of electronic battery testers lying to me and bought a 500A carbon pile tester.

https://www.amazon.com/gp/aw/d/B082PNSRXN