[Keetan Brumm]

Alright so straight to the point.
2012 2.4L
Alternator is brand new, probably less than 500k on it.
Battery is within 3 years
I changed for the brand new alternator originally because of this problem.
So what happens is randomly the car will more or less die every couple of months. I turn the key and it acts as normal, turn to start it and the dash will flicker, dome lights will flicker/strobe ect and you don't hear the starter even try to click, won't crank.
When it dies I can for example bring it to work no problem, I come out after a 7-8 hour shift and it's dead and does the above. I would assume a prasitic draw, but when checking the batt voltage it has more than enough to start, usually 11.9v or higher, sometimes a bit lower but depends how much I try to start it before giving up and checking the batt.
To sum up, it acts as if the battery is dead although it isn't.
So what I do to fix it, once it's in the garage or whatever,
Remove batt negative
Remove cable and connector from alt
Leave it sit overnight
Come morning, put everything back together
Put the batt charger on it for an hour or so depending how much I drained it from trying to start it
Then battery charger off, turn the key and bam starts up no problem.

This is the third time it's done this to me now, and I'm at my Witts end, I'm really hoping someone with more electrical understanding of these cars can give me an idea of what I may be missing.
Side note, I do have subwoofers hooked up into the car, without a capacitor, and I know these cars are very finicky for its electricity so that is an option, I'm going to disconnect the subs today. But in case anyone has had a similar experience or the exact experience I would love to know what fixed it.

What I have checked:
Battery connections tight at batt and jump posts
Battery cables not burnt, don't see any problem on them.
Alternator connecter checked, no frayed wire or corrosion
Alternator cable checked, clean no corrosion
Car still starts no problem so unlikely to be the starter
And it's happened 3 times, the second time I brought the batt to be load tested and it passed no problem
HELP LOL

 

[namretsud]

You said the battery cables were tight. Tight doesn't matter if both the post and all cable connectors aren't cleaned to bare metal and then coated with di-electric grease. There are about 3 connection points from the battery to the common posts. This is an area the vast majority of people totally think isn't an issue. Doing the proper steps clears up a lot of issue. Good luck.

 

[Keetan Brumm]

You said the battery cables were tight. Tight doesn't matter if both the post and all cable connectors aren't cleaned to bare metal and then coated with di-electric grease. There are about 3 connection points from the battery to the common posts. This is an area the vast majority of people totally think isn't an issue. Doing the proper steps clears up a lot of issue. Good luck.

Thank you, but I guess I should have elaborated.
Tight meaning tight, clean meaning cleaned to bare metal, used my grinder with brush attachment to ensure that.
As for dialectic grease there is a thin layer from when this originally started happening, because I didn't have much left. I ordered some more yesterday. Just reused what was originally on the connectors but will be redoing the grease once the new stuff comes in.

 

[Keetan Brumm]

An update.
I disconnected the batt and alt and let it sit.
I checked all fuses and none were showing any kind of parasitic draw (except my pcm fuse, but my ODB2 reader was plugged in, took it out and that fuse also dropped to normal draw)
Dialectic grease came in the next day, so I cleaned greased and tightened all the connections again.
And since the battery was on charge, once everything was connected it started up right away no hesitation whatsoever.
It's been a week or two I think?
And it just died again this morning. Luckily my buddy was driving by and happened to notice and gave me a ride to work.
Anyways when checking the voltage it had dropped down to 11.5v
I had tried starting it maybe 3 times before checking voltage.
First time it tried to start, cranked and all, but nothing.
Second time it again tried, but a shorter attempt and nothing.
Third time lights flickered and no starter click just flickering interior lights.
Before buddy showed up I tried jumping it from a spare battery I have. Didn't work.
Buddy and I tried to jump it, but we were low on time since I had to get to work.
It didn't want to accept the jump (mind you my jumper cables are relatively old so for both cases it could be that my jumpers are junk, and we could only leave the cables on for maybe 3 minutes before we had to leave)
Just for added information the new alternator I installed was a 140amp Mopar from rockauto.
And the battery is roughly 3 years old, motomaster. I don't remember CCa on it.
I'm going to try swapping my current battery with the spare, because I know the spare is good. And then charge mine up, then take notes of how much it drains every few hours outside of the car to ensure its a bad battery.
I just don't know what else it could be. No draw outside of the norm from the tipm, alternator is practically new and while watching voltage it was charging no problem.(ODB2 reader reads 14.7v-15.1 at the pcm while driving) I figure I would see some kind of a draw if any interior lights were on when they shouldnt be.
Wires all seem to be just fine, they weren't getting hot while the car WAS running, and very little corrosion or oxidization on any of the cables even before I cleaned them.
It did drop to -25° last night, but I doubt that would affect it that much. This same car has started in -35° weather with very little trouble only a year ago....
Oh and might be nothing but I figure I should mention it. Back in the summer when this happened the car was down for about a month. When I put everything back together I was putting the terminal connector back on the battery, and I believe it was the negative terminal, when I tightened it the terminal connector literally snapped open as if I had overtightened it. I only replaced the one terminal connector, could that be something?

 

[5rebel9]

Why not have both batteries taken to any part store that sells batteries and have a proper load test done on them for avail. CA and cell integrity. You need more than just volts to determine if a battery is good.
Also since you replaced the neg terminal end, how good and clean are the wire(s) attached to it.
Your posted weather temps make it critical for good connections AND good battery.

 

[Keetan Brumm]

Why not have both batteries taken to any part store that sells batteries and have a proper load test done on them for avail. CA and cell integrity. You need more than just volts to determine if a battery is good.
Also since you replaced the neg terminal end, how good and clean are the wire(s) attached to it.
Your posted weather temps make it critical for good connections AND good battery.

I would love to bring them both down, problem being I work throughout the week and by the time I get off all the places that can test them are closed, even Canadian Tire closed their auto section by the time I get off.
So I would have to do one at a time, and still have the car operational for work, which is a lot of switching, especially with our stupid battery location lol not to mention covid restrictions -.-

The cables and connectors are clean, greased and tight. No sign of corrosion at all really.

BUT I saw someone else's post about their glove box/center console lights staying on.
I checked it, turns out that the center console light switch had nothing pushing it down, so it was on 24/7
Not sure what kind of mechanism should have been there for it to turn off when closed, or where said mechanism went for that matter. But I took a fuse and some electrical tape, taped it down so that it stays off.
And just for good measure I cut and capped the glove box light as well.
Though I feel that two small low powered LEDs wouldn't really drain a battery that substantially, unless something else stays on because of them....

 

[5rebel9]

Yes that light staying on can give you the problem. Power draws like that are usually the first thing to look for when "dead battery" issues arise. I didn't suggest it as to your other postings led me to think it had been done already. This is a problem that goes back in the world of auto problems WAY BEFORE the Avengers were even thought of.

 

[namretsud]

You will always have starting issues with battery voltage at 11.5 and below. As Rebel said. you need to load test the battery. 3 years is close to what life expectancy is and in the cold north of the 49th it is even harder on batteries. As far as jumper cable go, don't get anything less that 4ga with replaceable jaw clamps. I helped a guy out with cheap cables that was trying to get his boat started and he couldn't get it to crank. Changed over to my cables using the same setup except my cables and it started right up. The amount of current transfer is critical on a boost and the cheap cables can't do it.

 

[Keetan Brumm]

Strange, you would think a little low power LED wouldn't pull enough power to cause an issue....oh well, seriously though no I never heard of this type of thing happening.
Hadn't seen it mentioned in any other postings till now, it never even came to mind. But maybe I just wasn't putting in the right keywords when searching. I guess it's like they say, out of sight out of mind. But yea that stuff is fixed so I'm hoping that was the issue all along, wouldn't that be nice, a $0 fix haha I'm never that lucky. If not I'll report back.

As for my jumpers, yea no they are just old and getting weak. They work when you can make a connection, but getting them to make that connection can be annoying to say the least.
Also looks like they are oxidized or something. Not sure if thats the proper term for it.
Either way ill be looking into a new set soon, just to have, and just in case this kind of thing keeps happening lol

 

[namretsud]

Don't cheap out on the cables as they could be a life saver.

On the low draw led light, the battery could be in bad enough condition that the led could be enough to put it over the edge.

 

[Keetan Brumm]

Alrighty sooooo yea it happened again. Was good for about 3-4 days. I had to jump the car off my spare batt to get to work.
So there is a battery place right around the corner from my work, they used to close at 5pm the same time as my store. But apparently they extended their hours till 6pm.
So after work I'll be going there and picking up a battery, and doing it tonight. And while I'm there (if they have them) picking up some new jumpers as well. I'll report back in a week or so if it continues after the new battery.