i use an external charger for my 18650’s, the other day when I was putting them in I noticed some nicks in the wraps. Is this ok? Should I replace the batteries? Can I use electrical tape to cover the torn spots?
Yes, you can use tape to cover those tiny little marks. Rewrap when you get some wraps. I have bigger Nicks in a few of my batteries but I am not overly concerned. If you are using a Mech Tube then maybe reason for more concern. Good Luck.
Just a note: IMR sells re-warap tubes for about $1 USD for a ten pack. Think I also got a 20 pck of ground buttons for on the positive ends of batteries there for like $2. All in, imho, IMR batteries is a good vendor for batteries and battery related items. Think IMR tried to match what TemCo does for delivery, I got the wraps before my payment cleared, at least I think I did. I know Temco sends my wire before payment clears, I get free wire for a week. *chuckles*
These insulator rings are dirt cheap and work well. I like them because they are a different color than anything on batteries presently visually indicating the battery has been re-wrapped, they are adhesive and work well.
With the Sony Batteries they print the info on the tube itself and not the wrap. These are good to re-wrap with (IMO), they just require you to feel the battery over and make sure there are no nicks in the wrapper and they allow you to still see all of the information on the battery.
Rewrapping batteries is the slickest thing going. I waited 3 months for my FT wraps for 15 minutes of fun to wrap the several batts I had that were scarred. Now I wait for the slightest mark and its.....WhooHoo rewrap time. Its well worth getting the battery wraps from wherever to give you the piece of mind that a scarred batt could cause a issue one doesn't need to deal with.