How does it work?
Our charging cable is almost like your regular cable, except for one very important difference. We prevent overcharging of the battery. Overcharging is defined as the period from the time the battery is fully charged until the charger is disconnected from the device.
It's actually quite simple. The cable knows when the battery is fully charged and automatically disconnects the device from the charger. It is as if you are pulling the cableout of the device, without actually doing so. Perfect when charging at night!
We are battery nerds. In case you are too; here's a little more information on how it works.
A typical cell phone battery uses graphite (made of carbon) packed with lithium ions in the negative electrode and a lithium manganese oxide compound in the positive. Between these two pieces is a thin membrane that acts as a separator, a battery cell. These cells are then packed tightly together and rolled, as in a traditional roll cake. The last ingredient is a water-based electrolyte solution that is injected. This contains the lithium ions.
When the battery is connected to the charger longer than necessary the separator between plus and minus is exposed to unnecessary wear. Imagine that you inflate a balloon until it almost bursts. When you let out the air, the rubber is much thinner and weaker. This is a good way to think about the separator inside the battery. When the balloon bursts, the cells will short-circuit and can start a violent chain reaction.
Where the problem occurs
When the positive and negative side of the cell come in direct contact, all the energy will be released at the same time. This triggers an intense heat, and can ignite the surrounding cells. It is this chain reaction that leads to fire.