Outdoor Siren - does it charge the Quick Release Battery Pack?

Just bought a Ring alarm system with an outdoor siren. This is probably a really daft question but if we buy a Ring Plug-In Adapter to power the siren would that also charge a quick release battery pack if fitted (with no solar panel or D batteries)? To me it'd make sense if the battery was trickle charged so it could act as a backup power source in the event of mains outage. The wording on the Ring website seems to read that the battery pack is only charged by either the solar panel or by removing it and connecting it up via USB but this might just be the way I'm misinterpreting it! Thanks!