Thought sabotaging enemy equipment to explode isn't.
Had this been a bunch of Russian or Wagner Group radio equipment exploding because they had been rigged by Ukraine, it wouldn't be a war crime - combatants don't stop being valid targets even if they are on leave and are at fault of endangering the civil population, possibly themselves causing a war crime by effectively using civilians as human shields in the process.
Not sure if sarcasm, but the article is actually super insightful into a few different methods bad actors could use to accomplish the same feat (short of giving them a formula, from what I can read, but I'm not a battery maker)