Beware of smart home devices with batteries!

Many households are now networked. Often, smart home devices are designed to help users save energy in the process. But many devices run on batteries, which is not a good long-term solution.

Many smart-home devices in the home run on batteries so they can be used anywhere, without wires. But is that really efficient? Especially when certain products, such as smart-home thermostats, explicitly advertise that they can help save heating energy? After all, battery operation tarnishes the bottom line.

Smart home with batteries: Expensive in the long term

Batterien haben eine endliche Haltbarkeit und sind dann leider nur noch Müll. Für ihre Herstellung braucht es nach Angaben des Federal Environment Agencyes (UBA) 40 bis 500 Mal so viel Energie, als sie am Ende bereitstellen. Das macht sie nicht nur zu einer ineffizienten Energieversorgung, sondern im Verhältnis zu ihrer Leistung auch relativ teuer.

Batteries in the smart home thermostat would therefore save heating energy, but also waste resources. And the thermostat here is just one example of battery-powered devices in the house and apartment.

Rechargeable batteries are better, but not optimal

Batteries are therefore often the better choice from the point of view of a more sustainable use of resources. At least this is true if they are used for a sufficiently long time and recharged frequently. According to the UBA, they then reduce the inefficiency of battery power supply in the smart home and other applications. Depending on their design, modern rechargeable batteries can be recharged 200 to 1000 times.

In principle, however, rechargeable batteries do not solve the problem – especially since they are more expensive to purchase. According to UBA, the best solution is therefore a third way: to choose corded devices whenever possible.

This is particularly suitable for stationary devices, and it not only saves resources, but is also significantly cheaper in comparison. Battery-free or solar-powered mobile devices can be an alternative. Some commercial smart home solutions for retrofitting already offer this option. However, examples here are mainly products that are operated near or at sockets anyway, such as smart sockets, smart speakers or hubs. However, the majority of smart home products would lose flexibility due to a cable. Just think about how you would have to power a thermostat on the heater or a smoke detector on the ceiling via cable – not ideal.

Batteries in the atechbook test

How well do inexpensive batteries from discounters actually fare against expensive brand-name products? atechbook did the test – with an astonishing result:

11 batteries in the test – inexpensive often better than branded products


  • Federal Environment Agency

With material from dpa