We're resigned to the fact that the constantly increasing power demands of modern gadgets will always outstrip slow increases in the energy density of batteries: however, high energy density is not the only factor that goes into making a good battery. Other factors that matter include the length of time that a battery can hold its power, how often it can be recharged, its price, how easily they can be recycled, and, of course, how often they explode. Disposable batteries come dead last in pretty much all the aforementioned categories, which is why we're happy to see that Uniross, a company that develops and manufactures rechargable batteries, has released its range of "hybrid" Hybrio batteries in North America. The Hybrio batteries mix the best of disposables batteries (fully-charged out of the box) with the best of rechargable batteries (can be reused / recharged) whilst keeping the price down, which is the main reason that people continue to buy environmentally damaging one-use batteries. A four-pack of fully charged Hybrios with a charger comes in at around £15, and each battery keeps 70% of its charge after a year, can cope with up to 500 charge cycles, and is protected by a three year limited warranty. We've heard this whole song and dance before, but apparently Hybrios are such an improvement over regular one-use batteries that the Worldwide Wildlife Fund recently let the company stick its logo on the packets -- and if there's anything that motivates us to buy things, it's a giant, environmentally-friendly panda.