'06 TSX Battery issues... General electrical troubleshooting

Looking for that fresh set of eyes out there. Something to possibly point me in a new direction.

Vehicle: 2006 Acura TSX Auto (all stock)
Location: Car just recently came to Austin TX area about a year ago from Seattle area
Issue: Won't start or restart after sitting over a few hours in temps less than ~50*
Battery: Replaced a few times over the course of this issue with different known to be good batteries.

At times, after jumping it, can drive to store, come out about 30 mins later and wont start.

Issue started a few months ago. Sometimes the car would be dead. No unlocking with fob dead. Hook up jumper cables and it'd fire up after a couple mins. after a couple times, pulled the battery out and slow charged it back to full. Ran fine until temps started dipping overnight. Had the battery tested and said it was OK but went ahead and bought a new one since they were on sale and didn't know age of current battery.

Again, car ran fine until temps dipped overnight a few days later. Seems to be around 50*. When car is dead, Battery voltage, via Fluke, was less than 2 volts. Hook up charger and after a couple hours, battery is around 12.8 volts and car starts. Running voltage was just under 14 iirc.

Even when battery is around 2 volts, if you hook up jumper cables for just a couple seconds, remove and fluke it, it is back to 12 volts. This lead me to believe bad connections. Replaced terminal connectors and cleaned. All was well until temps dipped again. Checked ground wire to chassis ground, cleaned bolt and replaced. Still issues when temp drops.

Did a current draw test to see if something was pulling from it overnight. Current Draw test results were <3 mAmps. Something in there just doesn't like the cold. Tried three different batteries I have on hand. There were no issues while it was in Washington and it got just as cold or colder there at times.

Intermittent electrical faults are a giant PITA, especially because it's hinged on temperature or very very coincidental. It can sit for over a week in >60* weather and fires right up.

I'm at a loss here and hope someone can do the "Hey dummy, do/try this" to me.

Thanks in advance for any and all help.

 

Check current draw when below 50 deg?

 

Can't remember temp when I did the current draw test, but that would make the most sense. May have to try in the am when I get home. See... Put 2 and 2 together... do tests when there are known issues hopefully it yields something that'll point me in the right direction.

 

Just wanted to put an update in here if someone looks this up. Got to digging around on the TSX forums and it appears to be the Handsfreelink (HFL) module. The HFL hasn't worked in awhile and I got around to researching that and found multiple people referencing battery issues. Not sure why my initial current draw tests didn't pick it up but I did it again and found over 200mA Disconnected the module and went down to less than 10mA. Charged the battery up today and will see at 6 am. was only getting 5 hours between charge and not starting. A new module is almost $1000... no thanks. It is just disconnected for now. I di read it is usually caused by solder joints weakening, mostly surface mount components. Might try the oven method of fixing them. Oven at 385* and place in for 8-10 minutes, allow to cool and reinstall. Lots of success stories on tsxclub doing that. Hopefully it just starts in the morning. First things first right?!