Prius 2021 LE Parasitic Draw / dead 12V battery

.01 amps that your multimeter shows is 100 milliamps. I think you need a higher level of precision to properly analyze your problem. .01 amps could be the rounded value of as little as 51 milliamps or as much as 149 milliamps. A parasitic draw of 51 milliamps would be nothing concerning, but a draw of 149 milliamps would be about 3 times as high as it should be (if none of the car's start up systems were powered on when you were taking the measurement). Now that you know the draw is less than an amp, it should be safe to plug your positive probe into the milliamp terminal on your multimeter. That will give you a truer picture of whether you have a problem or not.

I would guess that your car will not power on with the multimeter between the battery and the cable end either because it does not have a good enough connection to draw the power it needs or else the battery is dead. The 12.3 Volts that you measured at one point is low enough that there is no guarantee it can fire up the computers on the car. If the car is not driven on a daily basis, it is not surprising that the battery is discharged. A battery maintainer would be a good investment if the car is not driven regularly.

 

That looks correct, though clamps would work better. You should be able to turn on a dome light or something to see if it's working/reading.
IF YOU EXCEED 10A, you'll pop the the meter fuse. So if the car's self diagnostic fires the ABS motor or fuel pump, you'll likely pop the fuse.
Did you check the electrolyte levels in the battery? That one looks like the original battery. My OEM battery is a GS Yuasa. It's that time of year to check the electrolytes levels again, now that it's cooling back down. FYI; I had to top mine off last year - plates showing.

Why not just pull the battery and take it to an auto parts store to check it out?

Sorry, forgot to mention: on a Fluke meter, there's an independent amperage fuse within. If you popped that internal fuse; you'll get nothing - The meter will appear to work, but the amperage settings won't. The open circuit is your meter. You can get a clamp-on amp meter that'll read down to 25mA. That's about where it should be when it's asleep. Still pulsing for your key fob.

 

The CCA is 295, per the pic you posted. It is confusing, expressing the value as “CCA 295”.

 

I have a 2020 Prime and have to charge the battery frequently to keep it good. .01 amps is 10 milliamps. Once the neg cable is off your car the emissions monitors have to reset through a drive cycle. If you get a parasitic draw value, then what? It doesn’t mean anything is wrong.

 

Depending on the amount of parasitic draw?

 

, you are correct. 10 milliamps is nothing.

 

Your assuming that meter reading is accurate and it isn't a rounding error. OP couldn't get the car to respond to anything - Like there was an open in the circuit. Unless I could turn on a dome light or something and watch the meter move - I'd assume that isn't an accurate reading.

Just my two-cents....

 

If that was for me, I wasn’t assuming anything, but you are. I was correcting the statement in the thread .01 amps is 100 ma, which it isn’t. I know about rounding errors. It’s a pet peeve actually.