Hardwired Rind Doorbell

So, it’s cold here in Ohio and I noticed my device has 0 battery, odd, it’s been fine all this time. The device is hardwired, and it is sending power, but to no avail it seems. I assumed the device itself would be powered by he external powersource and slowly charge the battery in case of power outage. That makes sense to me. But no, i find out these devices ONLY run on battery and even though it should be getting more than enough power to keep the battery charged it’s “Too cold” at 44f. Seriously?

I hardwired my device assuming that it would be powered by that external source while keeping the battery maintained and at an optimal level. Why would anyone design it otherwise? Why would you allow it to be hooked up to an external power source if that powersource is rendered useless by a little bit of cold weather?

Anyway, can anyone suggest a different video doorbell that can be hardwired to accept external power source and USE that source to power the ddeviec while only relying on the battery in a power outage, you know, like normal devices that are set up that way…