If you're looking to do any radio work “in the field”, then you'll need to thing about your radio, antennas and how you're going to power your kit. In the field, without mains power, your choices are essentially batteries, or a generator. On this page, we'll be looking at battery power. The traditional 12V Leisure Battery seems to be a popular choice, as they are fairly easy to come by. These are 'deep-cycle' batteries capable of being. The capacity of leisure batteries is measured in Amp/Hours, and it's a case of calculating current usage to define how long your battery will last. Care has to be taken with batteries – risk include short circuits or damage to the casing resulting in leaks of corrosive battery acid. Also, read the instructions on how to care for your battery, to get the best performance and life.