Something you hear often these days: “My phone’s battery isn’t lasting as long as it used to,” or “I charged it all night and it’s already dead” or “It keeps hanging and I have to take out the battery”.
If you are having any battery issues with your phone, ask yourself: Are you using the charger that the phone’s manufacturer supplied in the box? Have you bought an “after-market” charger, bought off the shelf? Are you using a charger from another manufacturer to charge your phone? Did you buy one of those car chargers at the traffic light?
Since most phones these days have the same microUSB connector, people typically find any charger that fits and assume it ok.
However, what you might not know is that, not only could you be damaging your phone, but you could also be affecting the phone’s warranty.
The root of this issue is in the attempted standardisation by manufacturers to adopt the microUSB charger design as the charging port. The thinking behind this move was that, since you can make use of any charger, you will not throw your old charger away. You will therefore reduce e-waste, which is a win for the environment.
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However, while the physical design of the microUSB was adopted, the circuit paths inside the chargers are not universal.
In other words, the connectors are the same size but the chargers themselves are not the same. And just because the connector fits, it doesn’t mean that you should use any charger.
Four stages of battery charging
There are four stages that occur when you charge your phone:
There are four stages that occur when you charge your phone:
- Stage 1: As you connect your phone, the battery’s voltage quickly increases.
- Stage 2: The voltage peaks and current from the charger begins to decrease.
- Stage 3: The battery is fully charged and the charger cuts the current off from the cellphone completely.
- Stage 4: Standby mode, where only a top-up charge is supplied when the battery drops below a specified voltage.
It is critical that your charger “understands” these stages and is able to adapt accordingly.
Here is what you need to look out for:
The wall-charger is built to take normal current and adapt the current to a level that your phone needs. If you look on the charger itself, you will see a tiny label that contains the input levels, for example: "Input: 100-240v~".
The wall-charger is built to take normal current and adapt the current to a level that your phone needs. If you look on the charger itself, you will see a tiny label that contains the input levels, for example: "Input: 100-240v~".
This means that, if you live in a country where the normal household voltage is between 100 and 240 volts and you put this charger in the wall, it will not blow up. However, take a charger from the US that is rated only at 110v and stick it in a wall socket in South Africa at 220v, and you will trip the circuit breaker and bye-bye charger.
Next you need to look for the output voltage. Most cellphone batteries fully charge to around 4.2 volts and so the charger output must be greater than 4.2v. If the charger is only rated to output 3v, then that will not charge a 4.2v battery.
Finally we need to look at the output amperage, this indicates the maximum amount of current available from the charger for the phone to pull what it needs. If the phone requires 700mA to charge and you happen to use a charger with a 1A output, the phone will draw only up to the 700mA.
However, where your phone requires 700mA and your charger only supplies 500mA, many issues can occur, ranging from very slow charges to overheating and complete device failure.
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