What is CMOS-BAT-LEAK?
CMOS-BAT-LEAK is a critical-severity motherboard problem. Physical damage to the board caused by button cell battery acid. Typical causes include short circuit on the motherboard, aborted BIOS update process and age of capacitors. Follow the steps below to fix it.
Common Causes
- Dead battery CR2032
- Short circuit on the motherboard
- Aborted BIOS update process
- Age of capacitors
Step-by-Step Fix Guide
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1
Replace the CMOS battery on the motherboard
The highest-success first step is Replace the CMOS battery on the motherboard, which targets the most common trigger behind CMOS-BAT-LEAK.
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2
Use the USB BIOS Flashback function (if the board has a button)
If it's still not resolved, work through the rest of the steps — they're aimed at rarer mobo instability cases.
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3
Check the rear I/O panel for a short
"Check the rear I/O panel for a short" is worth trying when short circuit on the motherboard turns out to be the culprit.
Commands & Diagnostics
systeminfo | findstr /C:"BIOS Version"
Frequently Asked Questions
In most cases, dead battery CR2032 is behind CMOS-BAT-LEAK. Short circuit on the motherboard, aborted BIOS update process and age of capacitors can trigger it too.
Most CMOS-BAT-LEAK reports resolve after "Replace the CMOS battery on the motherboard". The rest of the guide above is there for the cases that don't.
CMOS-BAT-LEAK is rated critical severity in our database. It's worth acting on quickly rather than letting it recur.
In most cases, yes — the guide above resolves CMOS-BAT-LEAK without a clean install. Treat a reinstall as the last resort, not the first move.
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