rv8iator
Joined: 11 Apr 2006
Posts: 144
Location: Newberg, OR
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 Posted: Mon Sep 21, 2020 7:24 am Post subject: 18650 cells |
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Regarding 18650 cells... etc.
Bob's relayed test method would identify unqualified 18650 cells...
I purchased a few samples from different suppliers with ratings up to 4500 mAh. The ones rated at 4500 mah felt lighter in weight than the similar cells rated at 3000 mAh. A friend designs medical x-ray machines so I asked if he would x-ray one of the light weight cells and one "normal" cell. Unfortunately I don't have an image to share. A description will suffice. The light weight cell housed a much smaller cell. Hmmm!
Simerly I was replacing the output transistor in a regulated bench power supply. I recall it was a 2N3055. I found a "deal" on Ebay. Five for $5... Upon receipt I noticed the marking on the case didn't appear quite right. It was labeled STM... lightly scratching the marking it readily came off. Hmmm. Using a Dremel tool with a cut-off wheel I removed the top of the case. Voila! A tiny junction with .002" bond wires! That someone can make a living going to the trouble of counterfeiting transistors!
Caveat Emptor
Chris Stone
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C. Stone (RV8iator) |
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