And here it says that the batteries develop and improve, a factor of 10 times should be within reach. Now my N900 has lasted 4 years and runs application that Nokia never considered possible. But the charger, the software that drives the charging of the battery has not been changed - and changed battery needs a charger for more than 1280mA, according to the thread, one designed for 10 000mA. You need a charger that can "drain" and try to recover, change charge bursts. This is one benefit with the N900, access to open source code..