How Do Chargers Know When To Stop
Have you ever wondered how your phone charger knows when to stop charging your device? It’s a question that many people have, and the answer is actually quite interesting.
Most chargers use a technique called “negotiation” to determine when to stop charging. This involves the charger and the device that is being charged communicating with each other to agree on the appropriate charging rate and duration.
At the heart of this negotiation process is the battery management system (BMS) found in most modern devices. The BMS is responsible for monitoring the charge level and temperature of the battery, and it uses this information to determine how much power the battery needs and can safely accept.
When you plug in your device to charge, the charger sends a small amount of power to the device to initiate the charging process. The BMS then wakes up and begins to monitor the battery’s charge level and temperature. Based on this information, it calculates the appropriate charging rate and sends this information back to the charger.
The charger then adjusts its output accordingly and begins supplying power to the device at the agreed-upon rate. This process continues until the battery is fully charged, at which point the BMS will send a signal to the charger to stop providing power.
However, the charging process doesn’t simply stop at this point. Most modern devices will switch to a “maintenance” charge mode once the battery is fully charged. In this mode, the charger will continue to provide a small amount of power to the device to help keep the battery topped off. This helps to ensure that the battery stays at its maximum capacity and prolongs its overall lifespan.
So, to summarize, chargers know when to stop charging thanks to the negotiation process that takes place between the charger and the device being charged. The BMS in the device monitors the battery’s charge level and temperature and communicates this information to the charger, which adjusts its output accordingly. Once the battery is fully charged, the charger stops providing power and the device enters maintenance charge mode to keep the battery topped off.
It’s a complex process, but it’s an essential part of keeping our devices powered and ready to go at all times. So next time you plug in your device to charge, take a moment to appreciate the clever negotiation process that’s taking place behind the scenes!
