I am testing a bunch of 18650 button top batteries. They come from a large bank of batteries. The test are being done with a BT-C3100 Battery Analyzer Tester. All of the batteries that I am selling have tested above 3200mAh. These batteries were put together in banks using solder directly to the ends of the cells. It is not recommended that anything be soldered to the ends of 18650 batteries but it is a common practice. The solder has been cleaned off of the ends good enough for the batteries to fit a standard 18650 battery holders. Solder on the terminals would make it difficult to weld to. These are used batteries and they show it but internally test as almost new.
I have run a fish detector using a battery holder with built in
Battery Management System (BMS) and these batteries fit this holder. These batteries require a charger for Lithium ion batteries. Ebay sell a charger that charge 4 batteries at a time with up to 500mA for about $12. I have never used one of this brand of charger but IF they meet specks they should work fine. That would charge 4 batteries in a little over 6 hours. Also for sale are 2 of the BT-C3100 that have noisy fans.
I will be attending Copia and can bring items for sale with.
For sale
Batteries 18650 all test over 3200mAh $4.50 each.
Battery charger/tester Bt-C3100. Look it up on ebay for specks. $20. Each.
Send me a email if you want some of the above and if you will pick then up at copia. I cannot ship batteries.
Magicpaddler@sbcglobal.com

Are there any markings to show who made them?

SinglePortage: "Are there any markings to show who made them? "

No but maybe I can find out. They have a red wrapper on them which has been written on with a felt tip.

The batteries were manufactured by Samsung.

I know this older but does “C” rating affect true mah rating? Down the RC Car hole. With C being maximum available discharge rate. Conventional wisdom leads me to believe batteries with a lower C rating would be less susceptible to excess loss due to over drawing of amperage. I dunno though. And I like rabbit holes.