What cell is this? Marked TCB6RXA.

The model appears to be TCB6RXA.

Who or what is this cell? It came from a Dewalt power tool battery.

It measures out consistently around 2000mAh (all 5 between 1970 and 2010) and the current capability is very high - they do 16.5A in my modded S41,compared to only 15.0 for my best 30Q’s.

There are other markings on the cell, but they are different on all 5 batteries I pulled from this power tool battery pack,so I assume the varying markings are serial or lot numbers.

Red shrink wrap combined with a coloured washer reminds me of Sanyo cells.
A google search for sanyo 2000mAh 18650 batteries results in Sanyo / Panasonic UR18650RX
https://www.fasttech.com/product/1628902-sanyo-ur18650rx-3-6v-2000mah-rechargeable-li-ion

good 20a high drain cells.
running a pair in my homebrew regulated box mod.
good score!

Of course I googled TCB6RXA, but came up empty.

Lopan, your Google-fu is strong. Thanks!

I think these will be my “show off” cells until I stumble across something better.

They look a bit like these sanyo 2000mah li-ion cells, 3 vent, and has the same shape at the positive end.

https://es.aliexpress.com/item/100pcs-lot-freight-free-western-europe-SANYO-30A-18650-UR18650RX-2000mAh-battery-cell-3-6V/2027194827.html

John.