Adding an external Solar Panel to a Ring Doorbell 3

Hi, I bought Ring's Solar Panel mount along with the Doorbell 3, but since the Doorbell is on a wooden post facing north-west (cant turn it any other way), I do not expect it to get enough direct sun to do much charging. So I thought I'd just buy some external Solar Panel off Amazon, put in on the dead south side of the pole and wire it on. Would that work? The original Ring Solar Panel mount seems to work with 5.5V DC, right? So any Solar Panel having a DC output in the typical USB 3.7V - 5.5V range could provide a suitable trickle charge? Or am I missing something?