Nonvolatile BIOS memory: Difference between revisions

Revision as of 07:33, 6 December 2020

Revision as of 21:11, 18 January 2021

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|date=24 August 2020 |publisher=Intel

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</ref>This battery type, contraryunlike tothe popular[[Lithium-ion beliefbattery]],{{bywhom|date=November 2020}} is not rechargeable and trying to do so may result in an explosion. Motherboards have circuitry preventing batteries from being charged and discharged when a motherboard is powered on. Other common battery cell types can last significantly longer or shorter periods, such as the smaller [[CR2016]] which will generally last about 40% less time than CR2032. Higher temperatures and longer power-off time will shorten battery cell life. When replacing the battery cell, the system time and CMOS [[BIOS]] settings may revert to default values. Unwanted BIOS reset may be avoided by replacing the battery cell with the PSU power switch turned on and plugged into [[AC power plugs and sockets|an electric wall socket]]. On [[ATX]] motherboards, the PSU will supply 5V standby power to the motherboard to keep CMOS memory energized while the system is off.

Some computer designs have used non-button cell batteries, such as the cylindrical "[[List of battery sizes#1.2F2AA|1/2 AA]]" used in the [[Power Mac G4]] as well as some older [[IBM PC compatible]]s, or a 3-cell NiCd CMOS battery that looks like a "[[barrel]]" (common in [[Amiga]] and older IBM PC compatibles), which serves the same purpose. These motherboards often have a four pin straight header, with pin two missing, to connect an external 3.6v battery, such as the Tadiran TL-5242/W, when their soldered on batteries die.