Maybe I'm misunderstanding. The Victron Smart Shunt measured the lowest capacity? Does that suggest somehow that the Victron Shunt is less accurate?I thought soo too, but I had tested 4 cells together with JBD 150 BMS and I only read 271 AH and 3498 WH, when I tested cells by themselves on the fan tester It was giving 275-277 890 WH
Victron was the worst said 267 - 3471 WH for the 4 cell pack with bms.
So Fan tester dirtectly on cells = highest mah
fan tester with JBD test = middle mah
and victron 500a shunt = least mah
To me it sounds like there is something that is not as accurate as the other. Or in this case, if one is correct, the others are not. For me, I'd put my money on the Victron Shunt, vs the other two.