Mains powerbank recommendations?

[nb888]

Hi folks, long time lurking, first time posting here.
Looking to get some advice on something. We have an allotment with a shed in it that we have been renovating and adding to as part of lockdown projects etc. To try and get out of the house a bit more I'd like to spend maybe 1 / 2 days a week working in the allotment shed with my work laptop but at the moment the battery won't last a full working day of 8 - 10 hours.
The laptop is a Lenovo thinkpad which according to the mains charger / cable needs 135watts. Trying to figure out a decent portable-ish powerbank that doesn't weigh a ton that I could carry for the 15 min walk to the allotment along with the laptop in order to get me to that 8 - 10 hours. I know that Lenovo does their own powerbank but I'm looking for something a bit more general purpose that I could also use for my personal laptop / other small drain appliances etc.
Any suggestions would be gratefully received!

 

[nb888]

Hi - thanks for the replies. The laptop model is the i7 8750H with 32 gb RAM and 1 TB HD (the 20MF000XUK). I am not sure exactly whether it's possible to power this from anything other than a mains powerbank so I just assumed this is what I'd need. I wasn't sure whether one of the smaller "pocket" type powerbanks would the the trick in this case.

I am not exactly sure of the AH but the battery will last around 3 - 4 hours with light usage and probably half of that with more intense processing. The BEAUDENS powerpack one looks like it might do the job, looks ok to carry around and price is sort of what I was expecting.

Good point on the other methods eg solar power in the allotment which I was also considering, security is ok there and it is well out of the way but still slightly concerned the panels will go "missing" one day so looking for a more portable / secure method for the time being.