I use a Laundry Marking pen from the Office Supply to mark cells. This is better than the so called “permanent marker”. The Laundry Markers are the ones that never wash out of clothes, even in hot water. Don’t get it too oily before you mark it.
If you mark it….better check your spelling first, you ain’t gonna change it.
I have several metres of green shrinkwrap suitable for 18650’s - anyone in the EU who wants some - PM me - the cost will be the postage plus a few pennies. The cells I needed to rewrap have been rewrapped. Happy to supply it in 75mm chunks. And don’t pay till it arrives. Experience there.
Question, isn’t the heat shrink too tight? I know that you need your heat shrink to be 3-5mm wider than what you intend to wrap. If the typical diameter of a 18540 is 18.5mm, how does your 18.5mm shrink wrap fit with a bit of room to spare? I was wondering if I should go a bit bigger by 3-5mm to be safe.
No, as long as it can be pulled over the battery it is fine.
I have added a table with diameter and minimum width of the heat shrink tube for the common battery sizes. If you buy from somewhere where they do not specify that it fits a specific battery, I would recommend to get at least 1 mm extra.