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by Tade0 1498 days ago
Could you check the voltage on those cells next time you swap?

I've found that seemingly similar devices have very different notions of what constitutes a discharged battery.

I have a remote controlled humidifier and RGB LED - controllers for which use one and two infrared LEDs respectively. Both are powered by CR2025 button cells, which when new have an open circuit voltage of 3.3V and 2.7V once depleted.

The two-LED device considers a 3V cell "dead", while the one-LED will happily work at this voltage.
2 comments
nickff 1498 days ago
Voltage doesn’t tell you much about the state of charge of a battery (especially with no load being applied), and there may not be much energy left at a battery ‘floating’ at 3V. The cutoff may have more to do with saving money on the power circuitry than what the designer thought was a ‘dead battery’.
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LorenPechtel 1496 days ago
No-load voltage is not the same as the voltage under load.

The two-LED device drew more current and thus the voltage dropped more.

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