Making sense of battery technology

Originally published in GP magazine .

Written for GP magazine around 2002. This is the version I submitted - the published article may have been edited.

Anyone who uses a portable computer or other electrical equipment is dependent on battery technology, so it is worth understanding the different types.

The three main types of rechargeable batteries used in electrical equipment are Nickel Cadmium (NiCad), Nickel Metal Hydride (NiMH) and Lithium Ion (Li-Ion). NiCads are durable and reliable; they can be fast or trickle charged but shouldn’t be left in a charger for more than 30 hours. They should not be subjected to repeated shallow discharges and recharges, as this results in diminished performance, known as the “memory effect”. NiMH batteries are the next level up and used in computers, as they offer more power and are more environmentally friendly. Their biggest advantage is that they don’t suffer from the “memory effect”. Lithium Ion is the latest technology; they are basically better still, with more power available and longer times to discharge, but come at a cost premium.

To maximise your battery life: turn off backlights when not needed, or activate software that does it automatically. Lower the volume and turn off excess sounds like key clicks and screen taps, and use shorter sounds when possible for notifications of events, or even turn them off altogether. Turn the contrast to the minimum readable, as the darker the contrast the more power required. Remove any PC Card or Compact Flash that is not in use and insert them only when needed. Reduce the time before your PDA or handheld PC goes to sleep and make sure power-saving technology is turned on. Minimise your use of IrDA (infrared) or serial communications, as these require more power.

There are numerous gadgets you can buy to help; a second battery can be invaluable, or consider a second charger for work or for the car. A good backup policy is important in case of problems, to ensure no important work is lost. The latest thing in power technology, which may be available in the near future, is fuel cells, which use methanol as a fuel to create energy through a chemical reaction. The hope is they will be refillable, environmentally friendly (no toxic wastes), cheap to run (methanol is cheap) and provide power for longer.