The idea is for some people in a post-apocalyptic future to find these bunkers/vaults and be able to turn on the computers and charge the cellphones. How many years could the equipment last if they were stored in very good conditions (no sun light, no humidity, all covered in plastic or inside boxes)? 10 years? 100 years?
There are already some related questions (this one specific about cars), but in most of them the objects where abandoned in the environment or left behind without being properly stored.