Immax TRV 07703L batteries drained

does anyone here have any experience with Immax NEO Lite 07703L thermostatic valves?
I’ve installed them on some of my radiators, but the batteries are usually dead after 1-2 months.

As long as they are alive, the valves seem to work properly, the integration with zigbee2mqtt/HA is OK, although sometimes they seem to regulate too often - I can hear frequent short motor pulses, not sure if the battery is already too weak, the firmware is wrong or it is an intentional behavior.

Has anyone had a similar experience?