I love this one

I have been looking at getting one as well and there's a 20000mAh Kmashi power bank that has some positive reviews from MXPE users.

link below: https://www.amazon.com/KMASHI-20000mAh-Portable-Charger-External/dp/B01738J61A/ref=cm_cr_arp_d_product_top?ie=UTF8

Here's a 20 Ah one for $20 when you enter coupon code 8KZNDJ7M. Worked for me this morning.