first thing i thought of was
I have this:
Jump Starter, Annke High 10000mAh 400A Peak Current Car Portable Charger Power Bank Battery Booster, SOS LED Flashlight, Advanced Safety Protection, Multi Usage for Phone/ Tablet and More Charger https://www.amazon.co.uk/dp/B012SXUK24/ref=cm_sw_r_cp_api_ZQORAbA7H5QQW
Brilliant little thing, is it the sort of thing you’re looking for?
£99? It should be for that price!