My dos equis has chewed up the negative edge. Be safe and watch the chewing each time you take them out for charging. Don't want the sidewall exposed at all, if it gets to close I would call it time for rewrappng the battery. The IPV3 will do this also if you use the battery pull ribbon.
Illumination supply has precut wraps at 10 for a dollar in different colors.. Easiest to use a hair dryer to keep from melting a hole in the wrap. I just finished rewrapping all but my newest
batteries.
Edit, just noticed your location, my Family heritage is Irish.