A mobile phone charger works regardless of whether the charger is the right side up or upside down. As I know, batteries should not be charged with wrong polarity. How do those chargers accomplish that?


closed as off-topic by brhans, Michael Karas, Neil_UK, Voltage Spike, winny Jun 20 '18 at 7:58

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    \$\begingroup\$ Are you talking about the socket (AC)? \$\endgroup\$ – Jose Jun 19 '18 at 12:41
  • \$\begingroup\$ Actually that phone charger is not the actual circuit involved in charging the battery. The charger is really just a power supply, it makes 5 V DC and that goes (often over a USB connection) to the phone and the actual charging circuit is inside the phone. The power supply can be connected in two ways because it basically has no polarity on the AC (mains) side. \$\endgroup\$ – Bimpelrekkie Jun 19 '18 at 12:47
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    \$\begingroup\$ Alternatively you're talking about an iPhone's lighting port charger which is reversible \$\endgroup\$ – Makoto Jun 19 '18 at 13:23

The input power supply is AC therefore, on a two-prong charger, the polarity is immaterial because it's always changing/alternating at 50 or 60 times per second: -

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Internally the charger uses a bridge rectifier to convert AC to DC and it is the DC that does the charging. The polarity of that DC does not change when you rotate the charger.


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