Mine works fine on or off. I can't tell the difference. I have only small criticisms on the battery, very minor stuff. The air holes on the carto connection have small burrs left over from the drilling that love to pull off small bits of paper towel when I wipe them down while changing cartos. I have to pull the fibers out with a dental pick, it's something to watch out for if you're having any kind of draw issues. Also, the inside of the "barrel" where the center post is located is threaded instead of smooth like the regular batteries, so wiping this area down is a bit more difficult. Lastly the stealth cap threads seem to be a bit rough, so I have to be very careful when putting it back on after charging to make sure I don't cross thread.
These are very minor things , so don't get the wrong impression. I love my fat batt. I'll be getting a manual to go with it as soon as the ones with an off mode are available.
