Parasitic aux battery drain

It is not outrageously high, although it is still 20-30 mA higher than it should be.

This would indicate to me that your battery has seen better days. A proper load test will confirm. If your battery test is okay, you might have some a/m accessory that is always on, drawing those few mA.

If your key fob is more than 3 yards away from the car, then you are not waiting long enough for the car to completely quiesce.

 

"Proper" being the key word.
My Harbor Freight (cheapo) digital battery tester showed my lawn tractor battery was good, but it failed to start even after being on a battery maintainer. Not sure if all digital units are like that.

 

Just curious, do you know how old it is?

 

Yeah, that's not right.

 

@djimbuser is 57 milliamps what you measured? If you haven't, in a nutshell:

Disconnect 12 volt battery's negative connection, run wires from the negative post and car body out over hatch threshold and gently close the hatch on them. Wait 20~30 minutes, with fobs well away from car, then connect a mutimeter set to amps to the ends of those two wires. Set the meter to amps first (just in case draw is massive), then if nothing indicated, switch to milliamps.

If you're getting high readings, try pulling fuses one at a time, see if any of them drop it, say to the aforementioned 20~30 milliamps.

^ Ignore, For starters, see you have taken readings. And @rjparker is more on the ball.

 

Wrong

Your parasitic draw is 160 ma not 55 or 57 ma. This is killing your battery in four days.

This is where your problem is being feed from so if you want to diy this you have to trace all loads and inputs fed by the Dome fuse. To do so requires accurate wiring diagrams, theory of operation of connected ecus and good test techniques.

Good test techniques include use of a series connected amp meter with everything off and all doors and hatches closed. Simply have lights out is not enough as ecu can stay awake. Do not rely on a dc clamp meter in these ma ranges.

Good information shows where the Dome fuse connects to the Combination Meter and Body Ecus. One of these could be staying on. Good theory of operation helps determine which output from those ecus is fed by the Dome fuse. However in many cases of corrosion or failing ecus it may be necessary to measure individual connections.

With that said a low capacity battery could discharge faster. Low cost load testers put a low load on for split seconds and try to extrapolate what a large load over extended time would do. Better load testers are closer to old school units with big power resistor loads.

Finally, aftermarket accessories like radios, gps and obd2 devices often cause issues.

 

Agree, my oversight.

 

Would having the battery being actively charged during an amp draw test skew the readings? Just curious, and out of my depth.

 

Just by opening the door, your 'waking things up'. That's how it is on these new microprocessor driven cars. Test leads needs to be setup before hand and door switches bypassed, so the car's systems remains asleep. You'll still get a pulse every once in a while, SKS search for the FOB. Placing a constant current on the battery, while testing may skew test results. You don't know how the sensors in the car is going to react to that, as you know, some things in the car stays 'awake'.
The Fluke digital multi-meter takes an 'average' of whatever the probes are reading. ie. you can't find a 'noisy' DC power supply with it - unless your in AC mode. The human brain is a terrible thing to waste.......

Hope this clears some things up......

 

To find out the long term parasitic draw it is necessary to wait quite a while. The car does all sorts of odd things after it is turned off, and it goes on for much longer than one might imagine. What I do is open the hatch, stuff a carabiner in the receiver for the latch loop (until it clicks twice), then lock the car. Come back in 20 minutes and make a measurement. Leave the driver side window open and the hood up too. DO NOT FORGET TO REMOVE THE CARABINER BEFORE CLOSING THE HATCH when done!!!

I used to always see 20-25 mA parasitic draw. Lately I have been making a point of turning off the cabin blower before turning off the car, and it has been in the 10-15 mA range instead. Not sure if that is just because I have been waiting much longer or the climate control system somehow really consumes 10 mA while the car is off. I only noticed it because I have also been doing a long term experiment with a BatteryMinder to see if it can raise the 100% SOC voltage a little, or help with the low 80's SOH. Anyway, so frequently now I am looking at parasitic draw many hours after the car was turned off, and that is much longer than I waited previously.

Is the alarm system enabled in the OP's car? That causes a flashing LED on the dash. I don't see any variation correlated with that, but if the associated drop resistor on another car had lower resistance the current might be measurable. I can see the current go up and down with a similar LED in our 1998 Accord, but it is only a couple of mA.

 

Good sleuthing.

Googling "mtm powered by svr" is interesting.