Null reading after testing batteries-Opus BT-C3100

[RIHappyDiver]

I decided to test some batteries for the first time on an Opus unit that I’ve had for a few years. One of the batteries finished before the others but, instead of a numerical read, the display says ”null”. I’m not finding this as a result in the manual, so I’m hoping someone can fill in the answer for me. Is this a valid test result meaning the battery is shot, or is this a faulty test result meaning I did something wrong, or other? @tbone1004, I know you have/had this unit, so maybe you have some insight?
Thanks,

Erik

 

[tbone1004]

Null usually means the BMS has disconnected the battery or the voltage is out of range. What's the voltage of the battery as is?

What may have happened is during the discharge cycle the charger got the cell below the BMS cutoff threshold *which I've never had happen but is plausible if there is no voltage on the ends of the cell right now*.
Jump starting it to wake it up and get it to charge again is pretty easy thankfully

 

[RIHappyDiver]

Null usually means the BMS has disconnected the battery or the voltage is out of range. What's the voltage of the battery as is?

What may have happened is during the discharge cycle the charger got the cell below the BMS cutoff threshold *which I've never had happen but is plausible if there is no voltage on the ends of the cell right now*.
Jump starting it to wake it up and get it to charge again is pretty easy thankfully

I'm going to admit, right now, to battery ignorance. When you say voltage of the battery as is, do you mean what it's rated at, or what the charger currently shows? I don't know what the battery is rated at. It's a Panasonic 18650 that I bought about 4 years ago, and all of the markings have worn off. The charger reads null in every display for that slot. The other 3 batteries, one of which I got at the same time as the null battery, are still testing. I started the test about 6 hours ago.
Sorry if I'm providing info that you don't need, or just bad info, lol. I really appreciate your help, though.

 

[tbone1004]

I'm going to admit, right now, to battery ignorance. When you say voltage of the battery as is, do you mean what it's rated at, or what the charger currently shows? I don't know what the battery is rated at. It's a Panasonic 18650 that I bought about 4 years ago, and all of the markings have worn off. The charger reads null in every display for that slot. The other 3 batteries, one of which I got at the same time as the null battery, are still testing. I started the test about 6 hours ago.
Sorry if I'm providing info that you don't need, or just bad info, lol. I really appreciate your help, though.

Will need a multimeter to check voltage across the terminals to see the actual battery voltage. If the charger says null it may have tripped the BMS.

 

[RIHappyDiver]

Thanks, I’ll watch the vid this weekend and see what I can figure out. I’ve got an X-Tar charger/tester coming in today, I may try it out on that as well.
Thanks again!