My ring solar panel for my doorbell

The ring solar panel that I bought for my doorbell does not have a USB connector, it is hardwired to two screws on back of the doorbell. Does it do anything to keep the battery charged? It doesn’t appear so. The battery discharges same as it did before. I bough the recommended model from ring for my doorbell. The solar panels that I bought for my cameras do have a USB connector, did ring sell me the wrong thing?