How to Test a Battery Charger

A multimeter testing the end of a battery.
What You'll Need
Multimeter or receptacle tester
Electronic device to be charged

It's important to know if your electronic device's battery charger is working correctly. A broken one can obviously create problems with your device's functionality, but improperly charging the battery itself can decrease its lifespan overall. Fortunately, testing for issues is easier and less expensive than buying a new battery.

Step 1 - Be Sure You Stay Safe

An important part of using a multimeter or receptacle tester is safety. Overloading a multimeter or setting it to the wrong settings can cause immediate damage or, in the worst case, cause the device to explode. To safely test an outlet, you need to have a category III (for use on appliance outlets) multimeter. Categories are determined by the CEN EN61010 standard.

Receptacle testers must be handled with care as well. They can also be overloaded and the user must be careful not to touch any of the prongs when testing an outlet.

Step 2 - Ensure Outlet Is Working Properly


First, set up your multimeter by attaching pointed probes, turning it on, and setting it to the AC Volts setting. Then, insert the probes into the two vertical slots on the outlet, keeping in mind that type B (NEMA 5-15 or North American standard) outlets have the neutral slot on the left and the live slot on the right, along with a grounded slot on top or bottom. If your multimeter reads 110 to 120 volts then, your outlet is properly working. If it does not, find a new outlet and repeat until you find one that does work.

Receptacle Tester

Insert your receptacle tester into the type B (NEMA 5-15 or North American standard) outlet. If it indicates a properly working outlet, then continue to step three. If your tester indicates a broken or faulty outlet, then find a new outlet and repeat step two.

Step 3 - Check the Charger's Power Cord

Check the charger’s prongs. If the any are missing or bent, the charger should be replaced or fixed by a professional. Also, make sure there are no breaks in the wire or the wire’s protective plastic coating. If you do see any damage, do not plug in the charger! Have it immediately replaced or fixed by a professional.

Step 4 - Connect Device to Battery Charger and Check

Consult the owner’s manual for signs (LED signals, powering on when connecting to a power source, audio signal, etc.) of a charge, and then connect your charger to the device's input jack.

If it's receiving power, the battery charger is functioning; however, if there is none, the charger needs to be replaced or repaired by a professional.