At the supermarket, we look at the price/kg or price/l when comparing similar products. But we can’t really do that when it comes to getting an AA battery. For getting those, people usually go for names they are familiar with, such as Duracell or Panasonic, or go after attractive terms such as ‘PLUS’, ‘SUPER’ or ‘MAX’. But Denis Hennessy had other ideas. He bought a pack of every AA battery type he could find to do an experiment to see which brand provides the most bang for the buck.
he SpareOne has been designed as a back-up phone which can be kept in your emergency kit. Using that one AA battery, the device can deliver up to 10 hours of talk time. But its most amazing feature is that it comes with an isolator that prevents current discharge which allows it to hold charge for up to a whopping 15 years when you are not using it. But that depends on the shelf-life of the battery that is being used.