Another option always on the table is to use the same Handwavium™ that runs the STUN suits, if you don't want to deal with the constraints of modern day technology.
Battery and energy storage is the main problem in tech besides, y'know, getting the concept to work. Scientists have figured out how to create gems from nuclear waste ( !!!!) which themselves emit energy. Can create wearable computers and other tech with it and its gonna be neat
"Napoleon attacked by rabbits" so I had to go google search it. "The story of Napoleon being "defeated" by rabbits during a hunt in 1807 is a humorous anecdote, but it's not a confirmed historical fact, though it is mentioned in General Thiébault's memoirs. "