The adapter was buzzing with a life it shouldn't have without being plugged into something and he was focusing on the sound of the current moving around inside of it. He let practiced sending it through different pathways and even making little shapes with it whenever possible. He wasn't worried about breaking the thing but he was conscious of the possibility. You can't work in repairs and not be conscious of how to break things. Plus he'd done enough purposeful breaking just to have something to fix, that was really the allure of fixing things was sometimes you had to break them first.
He was lost in a bubble of thought that the girl behind the stand mercilessly popped with her pointed question. His face wrinkled up in distaste of her interruption and he sucked the electricity he'd pushed into the device back up into his body. He had been starting to miss the bit he allocated out anyway, it was a nice sunny day and losing a little bit of energy like that was sure to make him start hunting for sunny cat napping spots.
When he finally looked up at her it was with a slight frown. "Checking the validity of your piece here." he explained and wiggled the hand that held the adapter. It was true, not only did he play with the electronics like this but he tested all their pathways to make sure none of the pieces were fried or weak or anything. He didn't need to risk buying something that couldn't be fixed or would cost too much to fix to merit buying it.