By Shanen Yu and Zhen Li, Hangzhou Dianzi University, China

Most portable electronic devices are developed for high efficiency, low power consumption and reliability. This requires that their batteries offer a long life and high efficiency, too.

Batteries are widely used in charging systems. Some charging systems are a bit more involved than others, and one such example is metering electricity, which in some places differ from the traditional charging methods. In China, for example, electricity prices are divided into two tariffs: daytime (8a.m. to 10p.m.), when the power consumption is greater, i.e. peak electricity use; and night (from 10p.m. to 8a.m.). Charging electronic equipment during the night makes full use of electricity generated at night, which helps improve the power plant’s efficiency, thus saving on energy and reducing emissions.

Also, existing charging schemes suffer from a series of problems, such as high replacement and maintenance costs, long charging times, unstable charging temperatures (which is a fire hazard), and under- or overcharge that can lead to early damage of the battery. Hence, we have developed an intelligent charging system, where the charger automatically selects the period of low load for the power grid to recharge the batteries. This method also prevents overcharging the battery and hence it prolongs its life. In addition, we’ve designed it to displays the charge voltage, current and percentage of power left in the battery.