My old nest thermostat battery seems to be on its way out, after years of use. It now keeps on disconnecting wifi due to low voltage, and I need to charge it separately. Any good recommendations for a replacement? I’m not sure I need a wifi device as another nest or ecobee. Maybe something zigbee or zwave? Anyone have good experience with non wifi devices or should I just get another nest? I have a simple water boiler / radiator heat setup. Nothing fancy with air-conditioning.