@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.
Arduino says and I agree, in general, the const keyword is preferred for defining constants and should be used instead of #define
"Never wrestle with a pig....the pig loves it and you end up covered in mud..." anon
My experience hours are >75,000 and I stopped counting in 2004.
Major Languages - 360 Macro Assembler, Intel Assembler, PLI/1, Pascal, C plus numerous job control and scripting