It should be fine, they’re designed that way. 

“Memory effect” was a problem with most older NiCd battery systems. Lithium batteries are the opposite. If lithium battery systems are fully discharged, they can become fire hazards. Multi-cell lithium charging systems are designed to lock out, rather than become a hazard on full discharge. From time to time a lithium battery based device makes the news when it’s charging system fails.

In general, batteries don’t like heat. In my experience wireless chargers cause their device to remain warmer after the battery is fully charged. Even though it’s very convenient to grab and go when using a wireless charger, I try to minimize my use of wireless chargers.

I keep my lithium batteries charging. For units that I rarely use I’ll save energy by not keeping them on the charger (I’ll remove batteries if possible), but recharge them from time to time in order to prevent lockout.

Thanks, guys. I wish Sonos (and other mfrs) would publish a “best practices” guide to charging and how to maximize battery life for their specific devices. For the most part, I don’t use wireless chargers since I suspect the generated heat can’t be too good for the batteries. Unless it’s a matter of quick convenience or a top off, I generally use a USB-C cable wired to an appropiate power adapter. For the Roam, I use a 10W Apple power adapter originally supplied with my iPad.

If you search Sonos roam here you will find a huge number of posts about dead roams with bad batteries at around the 2 year mark. TBH I don’t worry about it and leave it off the charger  99% of the time.  Sonos seems to offer a FOC replacement most of the time. I would probably upgrade to a move or other brand for a portable if it does as my roam is a pos but that’s another topic. 

Here are some Apple charging suggestions.