I cant seem to find this information on my laptop..
I am wondering how many watts is my battery?
I wish to buy this laptop external battery
https://www.amazon.ca/Portable-External-Multi-voltage-Computer-Notebook/dp/B010D2RQ10
But I read that this bank will charge at 45W. I am afraid that if my laptop is more then 45W it will not charge 
I dont really understand what are these numbers anyway. My laptop battery has 4200Mah and this external battery has 10400Mah which would mean that it could charge my laptop almost 3 times.
I dont know what role does Watt play. But I have read that it can charge 45W laptops. What happens if my laptop has more Watt than 45?
Thank you everyone who helps! 