cell phone battery


Want to know how to check battery of cell phone? With lots of usage of various functions and apps, the battery consumption has become very high in todays smartphones. The usage of battery charge through internet either by data connection (2G or 3G) or WiFi also leads to quicker draining in cell phones. Its easy to test or check the battery with the help of the multimeter. It’s the voltage of the battery that is checked to know how much charged it is. The unit of voltage is Volts and its symbol is V. Although the screen of the phone indicates the charge level of the battery, you will need to check it with multimeter when your handset is dead! The method of checking a battery is the same for all models and manufacturers like iPhone, Samsung, Sony, LG, Nokia, Chinese phones, etc


check cell phone battery with multimeter


Steps to check the battery with the multimeter

  1. Switch off your cell phone and carefully remove the battery.
  2. Now search on the label of the battery for its given voltage. Most batteries of cell phones, digital cameras and tablets are of either 3.7V or 3.8V
  3. Place the battery such that its terminals face you.
  4. Now keep the multimeter (either analog or digital) on DC Volt setting. It may be indicated with either DCV or just V and a straight line with 3 dots below it. In DCV (DC Voltage) also, there will be many settings like 2mV, 2V, 20V, 200V, 1000V. Keep the setting on the number above the actual voltage of the battery. It will be either 10V or 20V in most multimeters. An indication of ACV or just V followed by a curved line means AC voltage. Do not use this setting as batteries run on DC voltage.
  5. Now touch the tip of the red probe of the multimeter on the terminal of the battery named ‘+’and touch the tip of the black probe on the terminal named ‘-‘. (The positive terminal of the battery is indicated by a ‘+’ sign and the negative terminal is indicated by a ‘-‘ sign.).
  6. Keep both the probes touched until you see a stable reading on the screen of the meter. If the reading on the screen is more than 3.70 for a battery of 3.7V, then the battery is fully charged. And if it is less, then you will have to charge it with a charger. It should show a reading above the charge of the battery.


If the battery is drained and showing 0 voltage or say less than 3.7, you will have to charge it with a charger. You can also charge it with a DC power supply. If after charging for a long time, still it is showing the same charge, then the battery is faulty. You will need to buy a new one as batteries are not repairable. If the reading of the battery is below 3.70V even after charging it, your mobile phone will not switch on.


Read our guide on How to use multimeter in mobile phone repairs


A funny traditional method of checking battery

Many cell phone repair technicians also check batteries with the help of the tongue which is a very unethical and equally funny method. Yet it will get you the result. They just touch the tip of their tongue to the ‘+’ terminal of the battery and if it gives a sort of current or spicy taste, then it means the battery is charged. While if it does not give the above effect and you if you do not feel anything on the tip of your tongue, than its charging is down. I am just writing this method for knowledge purpose and strongly advice against using it unless in an emergency!


How to check a fast draining battery?

Now, if your battery is draining very fast even after fully charging it, you will have to check it obviously. In such a case a multimeter will not help. This is because a multimeter will just show how much charge is there in the battery. But if the battery’s chemical inside has become weak or worn out, it will discharge quickly.


In such cases, you can check it any of the below 3 methods

  1. There are special battery check machines which will test it
  2. Test your battery in other same working model. If it discharges fast in that handset too, its become faulty.
  3. Put a new battery in your handset and check. If the problem is solved, your older battery is faulty.


So if the battery is faulty, you just have to replace it. But what if its good and still your phone is discharging? Then there is some short-circuit or hardware related fault in the PCB. Try servicing the PCB with a circuit cleaner.


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