Battery Concern with New Iconia One 10 B3-A50FHD

WJB-2

This September I purchased a new ACER Iconia One 10 B3-A50FHD and am worried the battery is faulty. Unlike the impressive battery performance in my previous Iconia, an A210, and my current Liquid Z410 and E1 laptop, the One 10 is a slouch.  For example, with the other devices at 1 percent battery level actual remaining runtime lasted/lasts 15 to 30 minutes to about an hour respectively.  With the One 10 at seven percent warning the battery drains to dead within two minutes, even though 25 minutes is shown to be left.  I called ACER with my concern and the technical representative tried to convince me it was because I had been viewing a video each time. But today I was typing a plain document when the battery again drained quickly at that roughly 7 percent mark.
Further, on late evenings with the former Iconia and current Z410 reaching one percent, turning the device off resulted/results in overnight build-up to 15, 20, 22 percent.  Similar though not quite dramatic is the E1. But the One 10: it will have remained at one percent and drain to empty within moments.
Purchased September 25, 2018 the new One 10 shows a June 2018 manufacture date; so an essentially new 6100mAh battery.  Would appreciate any and all impressions.

billsey

Yeah, it might be worthwhile to check and see how long it takes to drain each session. It's likely acceptable to do the 'use while charging' thing, but that makes the assumption that Android is able to correctly factor in battery drain during the charging cycle. It's better to just keep that out of the equation, I think.