Battery type CR2032 — Compatible cameras

The CR2032 is a lithium manganese dioxide button cell with a nominal voltage of 3 volts, 20 mm diameter, and 3.2 mm height — the name encodes exactly these dimensions according to IEC standard 60086. It is by far the most widely used lithium button cell worldwide and is available in every supermarket, drugstore, and electronics store. Typical capacity: 210–240 mAh. Characteristic is a very flat discharge curve — the voltage stays near 3 V for about 90% of the lifespan and only drops significantly near the end.

In the analog photo context, the CR2032 appears in two roles:

• As the sole power source in small handheld light meters: Gossen Digisix, Gossen Digisix 2, Gossen Digiflash, Gossen Digiflash 2, and Sekonic L-208 Twinmate. All devices on this page are light meters, not cameras in the classic sense — the 3 V lithium voltage fits the logic of these small digital meters.
• As a memory backup battery in later analog cameras: In cameras from the late 80s and 90s (e.g., Nikon F100, Canon EOS series, some data backs), a separate CR2032 secures the internal clock (RTC) and user settings, while the main battery only powers the actual camera electronics.

The complete device list with instruction links can be found at the top of this page.

It depends heavily on the device. For the Gossen Digisix and Digiflash light meters, there is no real off switch — clock, thermometer, and standby function run continuously, so the standby current is relatively high. In practice, a CR2032 lasts about 6 to 12 months with normal use, after which the display starts to weaken or the exposure measurement becomes inaccurate. With the Sekonic L-208 Twinmate, intervals are longer thanks to a real on/off switch (typically 1–2 years). As a backup cell in a camera RTC, the CR2032 usually lasts over 5 years.

Two handling notes: (1) Bought in stock, lithium cells easily last 8–10 years — self-discharge is under 1% per year. (2) Keep CR2032 strictly away from small children. Swallowed button cells can cause severe burns in the esophagus within a few hours — this is a real medical emergency, not just a precautionary phrase.