Compliance with TSA regs only relates to whether the battery is ok to fly. It really does not address the issue of carry on vs checked bag. I always do it in carry on.
There is a reason they don't allow loose batteries in checked baggage. Lithium batts can be a tremendous heat source and start a fire, even with their terminals taped. If there is going to be a fire, it is better to have it in the passenger compartment where it can be extinguished instead of in the cargo hold where it can (and has) cause the plane to go down. Even following the rules and keeping it in the device can not completely eliminate the risk. Anything you bring on a plane should have o-rings or lids removed so it does not pressure seal. Also, can lights are heavy. Putting them in carry on relieves some of the weight restriction burden from your checked bag. I had a legal sized carry on one time that was almost 80 pounds with can lights, cylinders and sorb. I made sure to hoist it into the overhead over a nice little old lady instead of being over my head.