Power Bank for 2017 MacBook Air (MagSafe 2 / Adaptor)

Can anyone recommend a Power Bank and MagSafe 2 Adaptor for my UK MacBookAir7,2 A1466 (EMC 3178)

Battery Type states 54 W h Li-Poly.

For Info.

I had to replace the original with a 3rd party Battery ages ago, and drains quickly, I would like the freedom a portable power bank would offer.

UK Magsafe 2 power adapter A1435, 60w , Input 100-240v- 1.5A 50-60Hz.