Micro USB Charger Compatibility

All USB connections provide 5 volts of power. It should be possible to charge any device with a standard Micro USB connector using a standard Micro USB charger.

• voltage - standard 5v from the microUSB charger.
• amperage - amps / current varies depending on the device connected.
• charging power - the product of current multiplied by voltage.

A standard device charging from a microUSB charger which fails to provide adequate amperage should not damage the device. The device will simply take longer to charge.

A standard device charging from a microUSB charger which is capable of providing amperage far in excess of what is necessary for the device will not damage the device since the device will only draw the amount of current it needs. Current cannot be forced onto the device being charged.

Because larger devices like tablets have substantially larger batteries than smartphones, chargers designed for tablets are capable of providing more current (measured in amps.) However, they only provide the amount of current being pulled from by the device being charged.

The USB charging spec provides a way for devices to check if the charger they're connected to provides the usual USB current (500 mA) or if it can provide even more current. Generally chargers are rated for much more then 500mA to provide a safety margin so that the charger will not overheat or fail. Typical Intel USB ports are rated for 800mA.

The connected device should be able to detect if the current is limited thus indicating the charger has inadequate amperage. The logic in the device will then adjust for "slow charging" as to pull less current from the charger. Although many devices are capable of this, not all have this advanced circuitry and therefore there remains a risk when connecting a high current draw device to a charger that is too small, ie: devices requires 900mA to charge, charger is only capable of producing 500mA, and the device tries to fast charge anyway. In this case the charger could produce excessive heat, which will cause failure to the charger as well as other possible dangers.

• There should not be a microUSB pin wiring different among chargers - all bets off on some cheap Chinese made products.
• There should not be a voltage different among chargers using microUSB - voltage will only dip below 5v if too much current is being drawn.
• microUSB standards are not regulated by government entities such as the European Union.