CMOS external battery \ VOGONS

CMOS external battery

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First post, by Martin85

Posted on 2022-11-14, 17:06

Martin85 Offline

Rank Newbie

Rank: Newbie
Posts: 63
Joined: 2022-08-12, 05:52
Location: Koper, Slovenija

Was wandering what is the highest voltage you would go on an external battery for the bios settings? I got rid of almost every barrel battery from my motherboards, bought myself some double CR2032 holders. That would give me 6-6.5V when fresh batteries are installed. The first prototype I chose to put two diodes in series and a resistor in parallel so to bring down the voltage to 5V more or less...

In your opinion could I go with the full 6-6.5V? Because soldering SMD parts in those holders is quite the PITA 😜

Reply 1 of 1, by Martin85

Posted on 2022-11-22, 20:05

Martin85 Offline

Rank Newbie

Rank: Newbie
Posts: 63
Joined: 2022-08-12, 05:52
Location: Koper, Slovenija

Noone?

Well I guess I will reply to myself 😉
Today I got a manual for a 286 motherboard that I got at home, it states that "an external 6V battery can be connected to...", also today while browsing through youtube, Retrospector used the same double 2032 coin cell battery to power the CMOS chip.

I guess 6-6.5V is still ok, even without any voltage dividers and/or diodes in between the battery and motherboard?

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