Can a powerful Power Bank charge a laptop with a dead battery?

I've just been given an Lenovo MiiX 520 which is a 2 in 1 laptop.

The battery is dead put it runs off the mains fine.

My question is that if I buy a Power Bank powerful enough to work on a Laptop will it work even with a dead internal memory?

I obviously could replace the dead battery but they are not cheap and it involves removing the screen and I'm bound to fcuk it up.