The default approach in the consumer smart home is to use battery powered sensors but this is a mistake in our view. Many manufacturers over state how long batteries will last and installing and replacing batteries becomes a big issue with larger numbers of battery powered sensors.
We don't install any battery powered sensors in our smart home unless they can report their battery level.
Where we have other types of batteries in use (e.g. in our UPS), we use sensors to monitor their voltage and thus their state of charge.
We use common models for all the sensors and all the types of sensors connected to our Home Control System. Combined with technology abstraction this means that any sensor added inherits all the capabilities supported by each model and our smart home. Essentially, every sensor connected becomes instantly very smart. They can all generate based on absolute values, rate of change, upper and lower limits, etc.
All sensors with batteries basically have a secondary sensor which is modelled and used to measure battery levels. If a battery needs changing we will get a notification to let us know.
Because we use technology abstraction we can use many types of temperature sensor in our smart home.
