Inkbird 8-in-1 Wifi Air Quality Monitor Weather Station

CONDITION APPEARS UNUSED, BUT MAY BE USED BECAUSE INSTRUCTIONS/MANUAL IS MISSING AND BOX EXTERIOR SLEEVE (BACK COVER HAS CUTOUT SHOWN IN PICTURE). The device was plugged in and started right up.  When unplugged the device turned off.  Not sure if the internal rechargeable battery was depleted or if it doesn't hold a charge.  Looking online the reviews below mentioned short battery life when unplugged. SELLING AS-IS.  NO RETURNS. "Onboard battery is hardwired, does not last after a full charge . It’s only useful for moving the device from room to room temporarily." "…after charging for a day or two the battery has held much more of a significant charge. I’m not sure if it was the cold temperature or what.,The battery life could be a little better but we leave it plugged up n anyways. Right next to the television.…
" …My only complaint with this device is that the battery life is not great.…