I carry a 10000 mAh battery pack[1] in my jacket[2], which besides powering the heater elements inside the jacket also provides wireless charging to my phone.

I carry a 10000 mAh battery pack[1] in my jacket[2], which besides powering the heater elements inside the jacket also provides wireless charging to my phone. I don't know about effectiveness, but 20-30 minutes of wireless charging gives 60% + of battery power on my phone, and while i don't regularly charge my phone fully in the jacket, only top it off, i charge the battery pack once every week or so, and it is very rarely at 0% [1]: https://www.amazon.co.uk/SANAG-Wireless-Portable-10000mAh-Compatible/dp/B07JYFW43P/ref=sr_1_7?crid=2NFVLEZ1QKCPW&keywords=10000mah+wireless+power+bank&qid=1580741624&sprefix=10000+mah+wire%2Caps%2C165&sr=8-7 https://www.amazon.co.uk/SANAG-Wireless-Portable-10000mAh-Co... [2]: https://www.ministryofsupply.com/products/mens-mercury-intelligent-heated-jacket https://www.ministryofsupply.com/products/mens-mercury-intel...