Product Description

E4809-045-167-C is a high-quality CMOS memory card created and manufactured by Okuma. This is a tiny memory found on computers and motherboards that are used to keep BIOS settings. Traditionally, it was known as CMOS RAM since it utilizes a volatile and less power CMOS SRAM (complementary metal-oxide-semiconductor). The memory is powered using a CMOS battery in case the system and standby power is off. Typically, the memory card carries a capacity of 256 bytes.

The real-time clock and the CMOS RAM have been incorporated to be one component and might not be used as a standalone card on the latest motherboards.

Generally, a memory battery is a lithium coin cell that has a life span of 3 years when the PSU (power supply unit) power button is switched off, the memory battery is not rechargeable and attempting to do that might lead to an explosion. Motherboards come with circuitry that prevents batteries from being discharged or charged when the board is switched on. Other famous battery cell types tend to have a longer or shorter lifespan. Note that extremely high temperatures and extended power-off duration will reduce the lifespan of a cell. When changing the cell, the CMOS BIOS and system time settings might go back to default settings. Undesirable BIOD reset might be evaded by substituting the battery with a PSU switch turned on and connected to the electric socket. In most cases, in most cases, the board come with a four pin header, with pin two unavailable to allow a connection of an external 3.6v battery.