Battery suddenly drained within 2-3 weeks

Purchased my Ring Video 2 doorbell in October 2019. I have not had to charge my hardwired doorbell battery in 12 months, but I just charged it a couple of weeks ago for the first time all the way up to 100%. And now the battery has depleted again down to 14% today. This behavior is not consistent. Do I have a bad battery? It does not make sense that the charge would last for 12 months the first time and then only 2-3 weeks the second time. I see an advertisement for a solar charger which feels gimmicky to me that they offer that as soon as it starts having charging troubles. I have not changed any settings recently as to how active the sensors should be between the last charge and before.