I can understand the impression, but having owned similar chips to what he described, at that price/performance point you are gonna get within 20min of the battery life of either of those chips with a good condition used Thinkpad.
I guess it depends on which one you buy. I can't get 3 hours out of a new battery for the w510, but the HP Spectre x360 I have for work can go the best part of a day without charging
