Agree - my Roam is always dead - played it last evening for a couple of hours (starting at 100%) - then turned it off overnight and this am it was 0%. It pretty much needs to be permanently plugged in - which kind of defeats the object… this is so poor it’s either a serious software fix or a recall - it’s a total fail as a roaming device.
To turn the Roam off completely and prevent Battery drain you need to press the power button for about 5 seconds. You will hear one tone after a second or so then lower tone after the 5 seconds. In this state the Roam will show offline in the Sonos app but the battery will not drain.
I think the Sonos use case for the Stndby mode is that the Roam is on a charging Qi base or plugged into a udb charger. This is the same with the Move in that if not on it’s charging station they will drain in standby over a few days.
In use, when fully charged, mine last well over 6hrs on Wifi. Not sure about Bluetooth but should not be much different