I've run into this a few times with bulk battery packs too. It's usually a single defective cell in the batch that drains down to nothing while the rest are perfectly fine. Checking them individually with a multimeter saves so much money compared to tossing the whole set.I had another failure of a Amazon Basics Alkaline AA battery. My flashlight has 6 batteries, inserted from a fresh package. The flashlight eventually went dim and rather than chucking all six batteries, I checked all the voltages. One battery was down to 0.1 V. The others were about 1.3 V. I replaced the bad one and got bright light again. Glad I checked.
I’m finding Amazon Basics has problems like this once in awhile.
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