A battery charger is probably the most common thing in our daily life. We need to charger to charge the batteries for our mobile phone, digital camera or our shavers. But are you interested in finding out how does it work?
All battery chargers have something in common: they operate by feeding an electric current through batteries to get a time period in the hope the cells in will hold on to a few of the power passing through them. That is about where the likeness finishes and between chargers starts!
The most affordable, most primitive chargers utilize that to the batteries before you change them away and use a constant voltage or constant current. Forget, and you're going to overcharge the batteries; take off the charger and you will not charge them enough, so they will run flat instantly.
Overcharging is not usually better than undercharging. If batteries are completely charged and the charger isn't switched off by you, they will have to get rid of the extra energy you are feeding in to them. They do this by building up pressure inside, which could make them rupture, leak compounds or gas, as well as burst and heating up. (Think of overcharging as overcooking a battery and also you could just remember to not get it done!)
The standby current on a charger needs to not be high to conserve energy. Energy Star puts five stars to similar modest chargers and mobile phone bringing on 30mW or less. Four stars - three stars to 150, 150mW - two stars to 250 and 250mW -350mW units. The average is this and 300mW gets one star. Energy Star intends to lessen current consumption of private chargers which are usually left plugged in when not in use.
Although standby current are low in a charger, we still need to unplug the charger to save money.