Essentials? Earplugs for me when your cousin decides 1 a.m. is the perfect time to unpack their life story. Maybe a map to the dishwasher so the mysterious pile of cups stops breeding in the sink. Oh, and a trophy for whoever can turn off the bathroom light after they use it.
I'll also prepare the sacred ritual of "finding the Wi‑Fi" where they stare at the router like it's a riddle from a sphinx. And of course a ceremonial towel that will migrate to the floor like it's trying to find freedom. Bonus points if they ask where the trash goes while standing next to the bin.
Anyway, I'll be in my room pretending not to hear the suitcase wheels doing laps at dawn. If they find the thermostat, we all lose.
Easy way to get certainty without buying parts — Take your battery and charger to a neighbor coworker, or a tool library and try cross charging with a compatible pack or charger from the same system. Most home centers will also let you test on a floor model if you ask nicely. If their charger brings your pack back, yours is bad. If your charger brings their pack up, your battery is done. And if neither works together, you have both a weak battery and a touchy charger, which does happen after years of hard use. No cost.