As part of its admirable ‘Think Gaia’ campaign, Sanyo has launched a revolutionary new type of battery. Quirkily titled, ‘Eneloop’ these Ni-MH batteries are rechargeable but, unusually come fully charged: standard long-life Ni-MH batteries quickly lose theirs. Sanyo claims Eneloops only lose 15% of their charge in a year. They are also recyclable and offer an impressive operating temperature range of -10°C to 50°C.

At present, 8000 tonnes of batteries end up in Australian land fill each year. Although Sanyo hasn’t established a local system of recycling yet, with each battery lasting a claimed 1000 recharges, there’s a long grace period before it needs to.

In our tests they, unsurprisingly, worked fine when replacing regular AA and AAA batteries but they also matched the peak performance of Ni-MH batteries used in our Nikon Coolpix S2 digital camera – lesser batteries take time to generate enough charge for flash and successive pictures.

At $25 for four AAs they come at a minor premium and will quickly pay for themselves because of recharging. Everyone should buy these, it’s as simple as that.