If a battery is "removable", that means replacing the battery is a normal, reasonable use of the device. Ergo, if the device breaks while the customer is replacing the battery, the manufacturer would need to replace it under warranty.
"Field replaceable" might be better way to describe it. If my flashlight runs out of power, I unscrew the tailcap, take out the 14500 cell, and put another one in it. I don't need tools and I can do it in the dark; it would be a major flaw for a flashlight if I could not.
