For $29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer.
If PPBUS_G3H stuck on 8.57V, battery is not charging.
You receive "Replace Now" alert for battery, which usually means bad battery.
Magsafe light stays orange even without battery connected, as normal behaviour for all MacBooks since 2013.
It switch to green ONLY when battery is fully charged 100%.
Try known good battery (even old), before wasting more time on it...