CMOS (BIOS) Battery Information
Overview
Consoles use a small internal CMOS battery (also called a BIOS battery) to store date and time information and BIOS settings while the console is powered off.
The battery used is a 3V lithium primary cell (not a lithium-ion battery). See below for specific battery variants used in each console type.
Airline restrictions may require the removal of this battery when consoles are transported by air. The battery may also become drained through normal use.
Effects of a Dead CMOS Battery
If this battery is removed or drained, functionality of the console will in general not be impacted. However, there are a few minor effects to be aware of:
- The console will lose its date and time setting when powered off, and will revert to an earlier date and time when powered back on.
- The console will lose its BIOS settings when powered off, and will revert to default BIOS settings when powered back on. All consoles use default BIOS settings already unless they have been specifically altered by the user.
- The console may initialize three times before booting when powered on (see Console Initializes Three Times Before Booting). On a Puck, a warning screen reading "CMOS checksum bad" may be displayed prior to booting.
A drained CMOS battery will not cause any loss of data from the Show File Archive. However, it is highly recommended to back up show data prior to transporting a console by air, in case of damage to the hard drive.
CMOS Battery Replacement
The CMOS battery in any console is a CR2032 lithium cell. However, the exact form of the battery differs between console types.
Some consoles use a standard CR2032 coin cell with no extra hardware. These batteries are commonly available from many online and brick-and-mortar retailers (search for CR2032).
Other consoles use a CR2032 encased in a plastic housing with an integral 2-wire lead and connector. This entire assembly must be replaced; it is not possible to remove and replace only the battery. This "CR2032W" assembly is available in either standard polarity or reversed polarity, which refers to the position of the positive and negative wires in the connector. Both polarities have been used in ETC devices; be sure to get the correct polarity for your device.
Accidentally installing a CMOS battery with the wrong polarity may permanently impair the console's ability to store time and date settings. However, this is very unlikely to cause further damage to the motherboard.
The table below shows each battery type and which devices they are used in.
| Name | ETC Part | Image | Description/Availability | Used in |
|---|---|---|---|---|
| CR2032 | BT130 |  |
Standard CR2032 coin cell without additional hardware. Commonly available at many online and brick-and-mortar retailers. Also available through any ETC dealer. |
|
| CR2032W | BT161 |  exact appearance may differ |
CR2032 cell encased in a plastic housing with an integral 2-wire lead ending in a connector. When viewed with connector facing you, key upward: +3V (red) on the right, common (black) on the left.  Available at some online retailers (search for "CR2032W"). Verify connector polarity before purchasing. Also available through any ETC dealer. |
see ETCnomad Puck Hardware Revisions
|
| CR2032W (reversed polarity) | none |  exact appearance may differ |
Same as CR2032W, but with connector polarity reversed. When viewed with connector facing you, key upward: +3V (red) on the left, common (black) on the right.  Available at some online retailers (search for "CR2032W"). Verify connector polarity before purchasing. |
see ETCnomad Puck Hardware Revisions
|