SolarKindle Lighted Cover is a solar case which lets readers “top up” their gadget simply by leaving it in the sun.

The SolarKindle Lighted Cover has a built-in solar panel and battery – and the battery is guaranteed to provide three months of reading time in “normal” sunlight, without dipping into the gadget’s own power.

Kindle solar case goes on sale this week, priced at $80.

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 is likely many SolarKindle-equipped e-readers may never be plugged in at all.

The SolarKindle Lighted Cover has a built-in solar panel and battery

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.

The gadget also offers a built-in LED light, powered by the reserve battery.

“Expose the solar panel to sunlight and your Kindle will be constantly charging,” says SolarFocus.

If your Kindle is running down and there’s no sign of the sun, you can switch the gadget to “top up” from the reserve battery. A blinking LED light tells you how much battery is left in the reserve as you charge.

“After fully charging the Kindle, the solar panel automatically switches to charge the reserve battery. When charging, the LED indicator light blinks green. A one hour charge in direct sunlight can provide almost three days worth of reading time on your Kindle.”

“For optimum performance, use the solar panel to continuously charge your Kindle – don’t wait for the battery to run out of power before recharging.”