A solar Kindle case lets readers 'top up' their gadget simply by leaving it in the Sun.
The case has a built-in solar panel and battery, which is guaranteed to provide three months of reading time in "normal" sunlight, without dipping into Kindle's own power.
The gadget goes on sale this week, priced at $80, Daily Mail reported on Tuesday.
Once the gadget's topped up, the SolarKindle diverts power to a backup battery.
Eight hours will fully charge the backup, which offers roughly three weeks' use. The battery also powers an LED light, which can run for 50 hours.
Given that Kindle is built for wireless use, with books and gadgets delivered to the gizmo via wi-fi or cellular networks, it's likely many SolarKindle-equipped e-readers may never be plugged in at all, the newspaper said.
The leather-clad pouch with charger panel and battery comes at quite a premium, though - it's $80, only $30 short of the price of Kindle itself.