08. Spare batteries

It is surprising how few people purchase a second battery for their laptop computer. The difference can be considerable. They are not cheap, and you will have to carry around an extra half kilo. But the bonus is that you will survive twice a long without connection to the power supply. It allows for better planning, and it means you can probably survive a whole morning or afternoon without concern. This is particularly important if you are stuck in a room (such as a lecture theatre) where there are very few power sockets. However, the important thing to remember is to recharge the second battery when discharged.