Ring Video Doorbell 3 with Solar charger - Please help me understand this

I have a Ring Video Doorbell 3, and after about a week or so of use, I bought and installed a Ring Solar Panel. The panel itself is fully exposed to 5-6 hours of direct overhead sunlight per day when weather is not otherwise a factor. When I installed the Solar Panel, I watched the battery percentage fairly regularly. It was 100% to start with a freshly charged battery (with the panel showing 'Connected'), and over the next few days, I noticed that the battery would drop 1%-2% per day, as it had prior to the Solar Panel. Then, I purposely ran it down to about 75% by repeatedly running Live View in the app one day while awaiting a FedEx delivery. Maybe a day or so went by when I did not really watch the battery level, and when I did check it, it said 100%. So my question is, does this device wait until the battery is at a certain percentage to begin recharging the battery - maybe for the purpose of battery health? Not an issue if that is the case. I just want to understand this. Thanks!