Battery keeps draining every few days ugh

[Quantico]

1. 14 Forester XT

2. 83k miles

3. No loads (lights, sockets, key fob far away, doors remain unlocked in garage, doors shut entire time)

4. Battery 10 mo. old Napa The Legend Premium Group 34

5. Battery tests well. After sitting overnight (not on charger) it will start the car very quickly. Afte

5. Dead every few days of sitting, started a few weeks ago (11.X VDC each time)
Smart charger used

6. Unusual charge behavior: my CTek smart charger used to complete a charge well less than overnight. Since I got the new battery, it will STILL be charging at 14.4 VDC when I check the next morning. It’s obvious the parasitic draw is so great it won’t allow the charger to trip off when the battery is actually full.

With a bench PSU, it draws more amperage when full than any battery I’ve ever charged. I can’t recall exactly how much, but will know by tomorrow morning.

/

My current plan of action is to fully charge it and then disconnect the neg lead for a couple of days to see whether the battery has micro shorts.

If the battery insnt self-discharging I’ll check the parasitic drain using my DMM.

If high I’ll start pulling fuses.

/

Any other ideas would be appreciated.

I am an engineer and pretty good mechanic. Your plan is what I would suggest.. you can pull one terminal off and use current mode to measure the drain current. You need to move the leads usually to do this.
Be aware that the meter cant deal with high current level like starting more than a second or two.

 

[Quantico]

I had a three month old battery from advanced auto that had a bad internal cell. Advanced required a 2 day test before they would replace it. The voltage read 6 volts after charge.

 

[redbone3]

In many cars it is possible to check for current drain by checking the voltage across the fuses.