If battery is a voltage source then why current is mentioned ? The current depends on the resistance in the circuit right? Then how can a battery give mAh as well as voltage?

  • 1
    \$\begingroup\$ mAh isn't a unit of current. It's a unit of how much current you can draw continuously for an hour before the battery dies. \$\endgroup\$ – tangrs May 13 '15 at 1:08

mAh is a measure of battery capacity, not instantaneous current. A 1000mAh battery can theoretically sustain a draw of 1000mA for one hour before it runs out. Broadly speaking, that means it could also sustain a draw of 500mA for two hours, or 2000mA for half an hour, but in reality battery capacity varies somewhat depending on how much current you draw; lead acid batteries, for instance, have significantly more capacity if discharged slowly.

The product of a battery's mAh rating and its voltage gives a rough approximation of power capacity (in watt hours) - rough, because a battery's voltage will also vary during the discharge cycle.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.