@timo88 That is fantastic. My purchase history is $40 for 10 in 2020, $31 for 10 in 2022 and $57 for 10 in 2022. All include delivery, and all in CDN dollars (multiply by about 1.3 to get USD. LiFePO4 is 90 to 120 Wh per Kg, translating to more than 1500 for 40gm, but the packaging may be involved. Similarly, for cost, it is $580/wH. Let us know how your testing goes.
First computer 1959. Retired from my own computer company 2004.
Hardware - Expert in 1401, and 360, fairly knowledge in PC plus numerous MPU's and MCU's
Major Languages - Machine language, 360 Macro Assembler, Intel Assembler, PL/I and PL1, Pascal, Basic, C plus numerous job control and scripting languages.
My personal scorecard is now 1 PC hardware fix (circa 1982), 1 open source fix (at age 82), and 2 zero day bugs in a major OS.