Two things worth mentioning.

You might want to check this again. 0.78m milliamp is a confusing reading. Either you mean 780 mA (pretty high), or you mean 0.78 mA (very low).

Also, some cars have some electronics active for a period of time after you turn off the car. You might want to check the reading again after the car has sat for 30 or 60 minutes. Make sure you don't open a door or hit the unlock button before you take the new reading.

Had one on my car at the vacation house, I used to lock the knob inside when I left.

OK.
I just checked this again. Car has sat all night without being connected to the battery. No doors opened nor is there any under hood light. I connected the VOM between the neg cable and post and got this reading:
http://forums.pelicanparts.com/uploa...1649345437.JPG
This is noticeably lower than what I saw yesterday upon initially installing the battery. I also didn't notice any 'sparking' when I attached the VOM. There was a noticeable spark when I connected the battery yesterday. So much so that the small amount of grease on the cable end smokes a tad bit.
I think 'systems' may have updated in the car during my fooling around with it yesterday and today they weren't drawing as much current.
It's a 2011 Honda Accord with all the options, ie NAV, security etc etc.

I'm not an electrical wiz by any stretch of the imagination so what do you think?
Sorry that first picture wasn't my best effort on the focus, this one is much better IMO. (I see picture resizing has done in the focus on this one too, sorry)
Thanks for any and all help I've received here.

http://forums.pelicanparts.com/uploa...1649346001.JPG
Another try at the picture.

That is a very low reading, 0.28 mA, so less than 1 milliamp.

Now, apologies for the potentially insulting question here. To make the reading above, is the battery disconnected, and you are connecting one terminal to the disconnected battery cable, and the other terminal to the battery? Said another way, is your ammeter connected in series to the circuit?

Yes, the positive cable of the car is connected to the battery + post and the meter is connected between the neg cable of the car and the neg post of the battery, so that is in series correct?

Perfect, yes. I think that you do not have a parasitic drain problem. You should be good to go!

Yeah, I was surprised at that low reading I got this morning. I expected it to be as high as what I got yesterday.
I still think I'll put the switch in when it arrives.
A .28mA drain shouldn't drain a big battery (700 CCA) like that even over two-three weeks of sitting.

I will also add that I agree with the prior posts about installing a battery cutoff switch. I killed my battery once when I didn't completely close the glove box. I didn't notice this until I went to start the car and got nothing. Over a period of a few days, the glove box light killed the battery. I also prefer to have a battery tender on my car with the battery disconnected from the rest of the vehicle.

I concur...one more test though. Check your alternator voltage output with the car running. Then also test with lights, fan, radio on.

https://www.autozone.com/diy/electrical/how-to-test-the-alternator-and-charging-system

Yes, I will do this too. Just as a point of ref, I tested my wife's CR-V when I parked it right after she came home from shopping this morning. I started the car and walked into the garage, got the VOM and put it on the battery posts. It showed 14.2v at the idle speed. This after having been driven @8 miles and shut off when she got home.
I'm waiting on the switch before connecting the battery in my car. Also waiting for the temp to come down........sheesh they said it was going to be hot, but really?
http://forums.pelicanparts.com/uploa...1649373218.JPG
Looks like I need to advance the time on that readout too...it never ends.

When you unscrew the knob on the cutoff switch, it will be easy to spot check current draw by measuring current across the gap.

This is one of the reasons why I went with Anti-gravity batteries for my cars. Now I don’t worry about them.

In a week and a half went from starting the car to 6.6v. As rbitmchi said, I have also seen a glovebox light stay on intermittently, or trunk/hood light.

I'm dealing with pretty much this same issue with a 2000 Lexus RX300. It has sat unused for a little over two months. I went to crank it up and nothing, dead battery. I jumped it off with a jump box, drove it around the neighborhood and out on the highway, parked it for a couple of hours, went to start it up and again nothing, dead battery. Ugh!!!

Sent from my SM-N950U using Tapatalk

@HobieMarty - From what I've learned reading up on this type of problem, that is the last thing you want to do. Don't expect an alternator to charge up a completely dead battery. They aren't designed for that kind of duty cycle and will burn themselves up trying to do it.http://forums.pelicanparts.com/uploa...1649780747.JPG
Here's the switch installed in my hot rod Honda.

My Prelude gets a lot of non use. Four years is about the max for each battery.

^^^ And today was the day that it wouldn't start and a quick charge didn't hold.

A trip to pick-up an Ever Start 4 year warranty battery for $110...I'm on the road again. Good for another 4 years.

I paid $94 for my three year free replacement Ever Start, but it's the first time I've paid for a battery since 2018 when I bought one of their 5 year replacement ones.

My records show I've had my car 10 year now. Wow, it's been that long already...

Happy Saturday! :)