I just had 2 new foscam cameras fail. I have seen wireless cameras with battery packs not sure I’m a fan, a small ups is $30 Tell me what you find. I have been looking at axis and lorex
Foscam E1 is pretty good. it's 100% wireless if a camera with IP 65 waterproof and simple to install, they have listed the detailed instruction in their site, you can check here https://www.foscam.com/faqs/list.html?cateid=0&cid=16