Went to leave this morning, almost completely dead battery!

Update:

OK,Battery, so far holding charge. Jumped it, started right up, went to 8.8, ran for a while and at 13.6. Relay is fine. only change was old owner had CD changer, amp, subwoofer in trunk and removed at sale. The wires were still connected to battery, so removed them. Stumped as to what caused issue to begin with. Going to wait a bit and go see if it starts again.

Oh sitting at idle is between 0 and 1, normal ?

THANK YOU FOR ALL HELP GIVEN, VERY APPRECIATED!!

 

UPDATE

So after above, left car alone for about 4 hours off battery charger. Went and checked battery, was at 10.8! Disconnected negative, rechecked, still 10.8. put on battery charger on and half hour later battery was at 11.98. Would this indicate an open circuit? Battery is only 3 months old and took in and had it tested, nothing wrong with it. Should each relay be tested?
BTW when I started it earlier, no click and started immediately.

 

Okay, good update, just not sure what you mean by "sitting at idle is between 0 and 1".
So, the battery tested good.
1. The car started with a fully charged battery and a jump. Did you try w/o the jump first?
2. While running, battery was at 13.6 volts. That means the alternator is charging properly but 13.6 is at the low end of acceptable, I'd expect over 14.0 volts with no accessory current draw - A/C, stereo, lights all off).
3. Disconnecting old audio stuff an excellent idea - could be a cause, so leave it out
HOWEVER
4. Battery drained to 10.8 volts, so it dropped about 2 volts in 4 hours.
5. Seems there is a current draw draining the battery. Make sure you interior and map lights are off. Map lights are often overlooked. Also anything plugged into the 12 volt accessory plug and have the car unlocked. Make sure the trunk light turns off when the lid is closed. Not sure if the 2010 Challenger has a safety circuit to kill all power after a specific time once the ignition is off to eliminate current draws draining the battery.
6. Next, (I would) disconnect the negative cable on the battery again and give it a full charge. Should be over 12 volts when full. Let it sit for at least the 4 fours again disconnected. It should remain at the fully charged reading of 12.x volts since there's no draw. Also verifies a current draw somewhere in the car.
7. For current draws: you need a multimeter that reads current at 20 amps. The multimeter is connected between the disconnected negative cable and the negative battery post. You should only see a draw of about 0.1 to 0.3 amps for running the computer. I'd expect you to see at least 0.8 amps or higher if there's a draw. Someone who knows how to set up a digital meter to measure current should do this. Remember that if the trunk or hood is open while doing this, any courtesy light needs to be disconnected.
8. If a draw is happening, start unplugging relays and then fuses one at a time until the culprit is found. (Take it out, put it back in, go to the next)

 

Jerry

So battery on slow trickle charger with negative cable off all night and battery just read 13.4.

Will let sit 4 hours again and recheck. It is 9:20 am here.

Thank you for helping me try and figure this out!!

 

Not sure if the 13.4 V you indicated is with or without the trickle charger connected. The battery should read well over 12.5 if fully charged - no charger connected. If it holds between 12.5 and 13.4 V connect the negative cable back up, it should be enough to start the car without a jump. (before the battery has a chance to discharge). After it starts, let it run for a little bit so the alternator can get the battery to full charge. Then turn it off and let the car sit again to see if the battery voltage drops again.

 

had the same problem , stopped at my regular gas station to get gas and then nothing dead not even a click. the owner came out with a jump box and nothing silent , he said you need a new battery I didn't believe him but he went in a came out with a new battery installed it and the car started right up. but no warning nothing good when i left the house but dead dead at this station and would not take a jump . well good luck

 

Strange, the sudden battery death.

Is "leadsled" past tense of "leadsl?" I wanted to leadsl, so I leadsled. Leadsling is the Bomb!
(absolutely random thought of the day.)

I like the smoothest of smooth lead sleds, by the way. I noticed no one has done a Challenger lead sled yet. But, how do you smooth an already-so-smooth car?

 

Get yourself a multimeter with a DC ammeter on it. Then you can directly measure draw from the battery just by clamping the probe around any wire without interrupting or cutting it. If there is a steady too-high draw, something somewhere is guzzling too much power. Someone has a really powerful tracker on your car?

 

Mthrt F'ker a tracker causes this? I found out I had one on my car my ex had put on. Sorry I havent been here, several family losses and just have not been online. Still have issue with car, just had it parked right now and driving my 4x4. Will be going to take care of problem soon. Just not feeling like doing much.

That MF was not at you! But really pissed it could be where issue started!

 

What happened? A tracker caused your battery to die?