How are batteries rated?

There are two ratings on every battery: volts and milliamp-hour (mAh). The voltage of the new battery should always match the voltage of your original. Some of our batteries will have higher amp-hour ratings than the original battery found in your device. This is indicative of a longer run-time (higher capacity) and will not cause any incompatibilities. Remember: in some cases, the voltage will differ from the original battery. This often happens when both a Li-Ion battery and a Ni-Mh battery are available for the laptop.