So I dug out all my other 18650 cells, which are all from the same manufacturer, and which are labelled as 4000 mAh. One of them weighs 44.19g, but the weights range from around 36g to 46g. Aha, I thought, problem solved - Simply replace the original with the one weighing just over 44g.
However what I didn't count on was the different heights of my stash of 18650s, All too tall to fit into the battery holder on the iSpindel board!
So much for them being a standard size. As a mate of mine said, the great thing about standards is that you have so many to choose from.
