I only use my A5 as a reader, so thought I'd see if it could double up as a power bank for my iPhone...
https://imgur.com/9de0EuT
It works, charging at about half the speed of a regular iPhone wall charger (or 10% of peak fast charging).
The cable type seems fairly rare, I got mine from Ebay:
https://www.ebay.co.uk/itm/Micro-Usb...53.m2749.l2649