Tag: bios battery

Odin/Dallas RTC modules with integrated battery (WHL #107)

Have you ever desoldered one of those ancient RTC modules from an equally ancient PC mainboard?
There was a time in the 1990s where board manufacturers abandoned the old leaky NiCd buffering cells and instead of hopping onto the CR2032 lithium train. They used Dallas modules (back when Dallas was still Dallas and not Maxim…which also ceased to exist in 2021 when they were bought by Analog) that served as real time clocks and battery backed SRAM for some 100 bytes of BIOS settings.
Well yeah, these are terrible as the battery isn’t replaceable since it is moulded into the bulky case. […]

16th March 2025 16th March 2025 By Bzzz In 3 Comments

CR2025/CR2032 battery dummy for power consumption tests and a hungry Supermicro board (#P21)

This bugged me for quite some time now: Ever since a very nice dumpster revealed a stripped Supermicro server chassis including a Supermicro X8DTL board (Dual-1366) to me, the BIOS battery of that system seemed to be empty all the time. You see, I use this machine as an offline backup, so once every couple of months I fire it up, transfer my data, and unplug it from power and ethernet. And almost always it doesn’t start right up because the CMOS data is gone. Ideally it should be a headless unit, so that’s highly inconvenient.

I finally got around to test this – the fix will be another project for some day in the future. […]

8th March 2020 15th February 2020 By Bzzz In 2 Comments