MOSFET Astable: NP-BX1 Rundown

After eight months from a full charge, an old NP-BX1 lithium battery has come to this:

Astable green - NP-BX1 - 2.31 V
Astable green – NP-BX1 – 2.31 V

The astable still ticks along at 1.4 seconds per blink, but the green LED barely lights up from a 2.1 V battery:

Astable green - NP-BX1 - 12 mV 100 ohm
Astable green – NP-BX1 – 12 mV 100 ohm

A pulse of 12 mV across the 100 Ω resistor puts the LED current at a mere 120 µA: no wonder the poor thing wasn’t visible in ordinary room light.

Another full charge restored its vigor for another couple of seasons.

3 thoughts on “MOSFET Astable: NP-BX1 Rundown

    1. And it was the Genuine OEM Sony battery, too! [grin]

      I was hoping for a year. Maybe a pair of fresh alkalines will get there?

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