Microbattery.com offers you these tips to help you properly choose the correct CMOS battery for your computer's BIOS application:
- Determine your CMOS battery's voltage.
- Determine your battery type: Is it primary or rechargeable? Primary batteries may be alkaline, lithium CR type, Lithium BR type, cylindrical, or wafer. Rechargeable batteries on the other hand, may either be nickel cadmium (Ni-CD, NiCD, or NiCad), nickel metal hydride (Ni-MH or NiMH), or lithium-ion (Li-ion or LIB). Take note that Ni-CD and Ni-MH batteries have a single cell voltage of 1.2 volts, so battery packs having a multiple cells will have higher voltages of 2.4, 3.6, 4.8, 6.0, or 7.2 volt. Some primary batteries, such as the 3.6 or 6.0 volt lithium cylindrical and lithium wafers cells or packs should not be confused with the rechargeable Ni-MH or Ni-CD packs. These lithium batteries are not interchangeable with rechargeable battery packs, even if they have the same voltage.
- Determine the battery size and pack shape: If physical dimensions are different, the replacement battery may not fit into the required space.
- Verify the rated mAh capacity: The replacement battery you purchase should have the same or similar capacity to the mAh capacity of the original battery. Although a slight difference may be acceptable, if the replacement battery is a rechargeable cell or pack, a non-matching mAh capacity may indicate a wrong size pack.
- Take note of the connector type or pin locations: Verify the connector is the same as that of you replacement battery. For cells and packs with mounting pins, verify the pin position is the same as that in the replacement battery.
The most common replacement battery for PC desktops is the CR2032 3 volt primary lithium coin cell. It is a bare cell that is pressure fit or clipped into a coin cell battery holder that is soldered to the motherboard. The battery can be replaced by hand.
