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2nd-generation magnetic AC power adapter for MacBook products, first released in 2012. Not compatible with previous generation systems. Available in 45W, 60W, and 85W versions.

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Check if work with multimeter

Hi everyone,

I have x3 MagSafe 2 - 85W adaptors which I want to sell but I want to be sure they are fully working. I sold my old MacBook and non of my friends have MagSafe compatible Mac so can't check it direct way. I have multimeter at home.

How can I check this charger with multimeter to know if its work or not?

Would appreciate your help

Update (12/09/2022)

@geirandersen I set a multimeter at the setting (see pic) and the it showed 3.1

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@roderos I’ve attached a pinout image for the MagSafe 2 charger.

Test black probe on Ground and red probe on Power. Both Power pins should have very similar output. If there’s a large difference or the voltage if the voltage isn’t ~20V, you have a bad charger. By large difference I mean anything more than a few millivolts.

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So the output from both Power pins must be around 20V?

I have 85W charger.

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@roderos Yes. You can use any of the Ground pins, but both Power pins should have ~20V. Output voltage doesn’t change with Wattage rating. It’s the amperage that it can possibly draw that is higher on the higher rated chargers.

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@geirandersen just have a chance to test it out now. sorry for silly question, do I need to have charger plugged into the wall to test it?

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@roderos Yes, the charger must be plugged in to the power, otherwise it has no output ;)

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@geirandersen thanks :) I tested x3 chargers both pins an all of them show 3.08-3.1 at DC Voltage 20. Does that mean that they work at full power?

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