I reported this way back in UI2 and am still seeing the same in UI4 .1086
When the battey capacity dips below 30% (partial yellow) it will show a full battery (full green ) on the UI.
If you check the reported battery % under the advanced tab it reports 255%. Setting a low battery warning in device, notifications will not save.
This is a huge liabilty issue for MCV who has known about this for over a year. To rely on this to protect ones family / investments could result in disaster.
JOD.