Ok, I thought I was done with this old technology. But, my empower adapter died some time ago. Most planes don't require an adapter anymore, but I have at least 3 roundtrips coming up of 8+ hours per direction with AA (767, 772) where the inflight power will require it. I've had my own external battery for laptops so haven't even bothered. But I can't find a tip for my new laptop that'll work for the battery. So any advice how to power a Lenovo t440s or Yoga 2 Pro (they have the same tip, but I haven't seen one that goes with an adapter or external battery)? Either an empower adapter or external battery with tip that's compatible? Much obliged for any advice.