How to read Smartphone charger specifications

Hi there, let’s say you are in the market for a new charger. You want a spare or your old charger just gave up the ghost. Choosing a new charger can be tricky. There are so many charger brands in the market that it is so easy to get confused and only very few people know how to read smartphone charger specifications.

Different people approach buying a charger differently. Sadly, a majority of buyers believe that all chargers are the same or do the same thing. So, they just go out and pick up the first thing they see and return home. Others on the other hand may rely on other people like their family, friends, neighbors, adverts and sales people for advice.

The first approach is obviously a very bad approach. One could pick up a bad or incompatible charger that may damage their battery. The second approach is slightly better, but it would require that you ask someone who knows their onions. Taking advice from adverts or salespeople is a rather bad idea. These people only have one goal and that is to sell products. They do not care if it is good or bad for you. All they want to do is sell.

So is this a hopeless situation? Absolutely not. This post should help teach you how to read smartphone charger specifications. On every charger, there are words and letters written in strange spooky language. Oh no πŸ˜‚, they are not.

Charger specs


First off, you would see a model number of some sort. It means the model or build of the particular charger in question. You usually see something like Model: SDC-48W or Model:MDY-11-EZ. Model numbers are how manufacturers label and keep track of their products.

Next up, we have input. Input simply means the type of voltage that the charger can accept. Whilst different countries have different voltage standards, you can save yourself the headache by picking a charger with an AC input of 100 – 240V. This should ensure that your charger works with any voltage, anywhere in the world.

Finally we have output. Output simply means the type of power that a charger can supply to a battery. You can decipher this by simply multiplying the V value by the A value. For example, if you have a charger with an output of 5V and 2A. The power rating of the charger will be (5V x 2A =) 10W.

Read: Voltage, Current, Resistance and Power

Output voltage should not be a problem as most chargers conform to the 5V output standard of the USB specification. If a charger has an output of less than 5V then you should definitely not buy it. A charger rated below 5V that does not conform to the USB standard. It is going to hurt your device. You should also avoid slow (5V/0.7A or 700mA) dumb generic chargers as using them may also harm your device in the long run.

Read: Fast charge on Smartphones explained

Fast chargers

Fast chargers can have outputs as high as 20V (Q.C 3.0 and 4.0+). As long as your phone supports fast charging, they are very safe to use. An intelligent fast charger may have different output power ratings. For example, my Xiaomi charger here has the following ratings: 5.0V-3A (15W), 9.0V-3A (27W), 12.0V-2.25A (27W), 20.0V-1.35A (27W), 11.0V-3A (33W Max).

These figures show that there is a buck inverter in my charger and it can adjust voltage and current supply intelligently without sacrificing power delivery. The highest power ratings on a fast or three stage charger are meant for the rapid phase charging while the lower power ratings are meant for slow and trickle charge.

Read: How Smartphone Batteries Charge



All good chargers should have good input/output voltage regulation, low heating and insulation to prevent electric shocks. They should also have symbols of certification showing that they have undergone rigorous testing and are fit for personal use. These symbols include EAC, CE, FCC, MFI, RoHS etc.


You should only buy chargers that are compatible with your device for the best charging results and a long battery life. If your phone does not support Fast Charge, getting a Fast Charger is actually rather pointless. You should simply get a 10W (5V/2A) charger. This will charge your phone as intended by the manufacturer.

If your phone does support fast charge, then only use a fast charger that is designed to work with the fast charge technology on your phone.

  • If you use a phone powered by a MediaTek SoC, get yourself a Pump Express Charger.
  • If you use a Snapdragon powered phone then a Quick Charge 3.0 charger would be appropriate for you.
  • If you use a Samsung device that is maxed out at 15W or 25W for example, buying a 60W charger is a blatant waste of money .

Do nots

  • Do not buy cheap generic chargers from roadside or traffic vendors. Avoid those chargers if you want your battery lifespan to last longer.
  • Do not buy chargers that do not conform to the 5V USB specification.
  • Do not buy chargers with dents or deep cracks.
  • Do not buy chargers that smell funny like burnt rubber or plastic.
  • Ensure to only buy chargers from your manufacturer or other solid brands like Aukey, Anker,Β  Baseus, Celbro, Flovme, Essager, Xiaomi etc.

Please leave a comment if you have any difficulty and remember to:


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