Among the many laptops and desktops that Lenovo announced at CES 2025 is an intriguing peripheral: the Self-Charging Bluetooth Keyboard. This unique productivity keyboard ditches the traditional battery, instead utilizing solar and ambient light to charge and store energy.
The Lenovo Self-Charging Bluetooth Keyboard might seem like your run-of-the-mill keyboard, but it comes with a party trick that might just save you a buck in the long run. Using advanced photovoltaic technology and fast-charging supercapacitors, the keyboard actually harnesses ambient light to store energy, eliminating the need for disposable batteries.
No lithium, it’s got a capacitor. Those things can handle a lot of charge cycles
But they still have a limited lifetime of a maximum of 10 years, regardless of cycle count.
Where are you getting that number? There are many different types of supercapacitors, which cary in lifespan quite a bit, the conditions (mostly voltage and temp) also have a big impact. The article doesn’t specify the type of cap used.
For instance this paper tests a supercapacitor rated for 2.7V at 2.5 and 3v. At 2.5v the cap is estimated to have a lifespan of 100yrs, with 3v scenario it’s 10.
Keyboards don’t get very hot, and the voltage draw is very predictable so I don’t think designing a long lasting capacitor for this usecase is particularly tricky.
I would be worried about the lifespan of the solar panel, but at least it’s still usable without that.
I suppose you’ll have to do a 10$ repair on your decade old keyboard, and recycle the remains