Nicely summarized, this was the post you were referring to above. These thermostats shine when on C-Wire. Alkaline batteries on the other hand tend to last about 2-4 months depending on usage and the mesh quality and should be within 30-50ft of another z-wave repeater device. There is an option battery save mode in DTH preferences page which reduces polling requests from the platform to save battery. Using 1.5v lithium batteries can double/triple that lifespan but you need to watch the battery dead reporting threshold which will be higher than that for Alkaline batteries. You can also check out the [RELEASE] Configurable Low Battery Warning/Notification/Monitor and Device Monitoring Alerts app which is tuned for creating configurable low battery rules.
For folks who don’t have a c-wire option on their the HVAC wiring, check our the Venstar add on which can create and extra wire/C-Wire by using your existing wiring.