whiskeysixkilo t1_jeckxap wrote on March 31, 2023 at 12:51 AM

Reply to comment by TheBestMePlausible in eli5: Why do seemingly all battery powered electronics need at least 2 batteries? by OneGuyJeff

They do. Lithium (Li-MnO2) batteries output 3V.

Lithium ion batteries output around 3.7 to 4.2V.

Alkaline batteries output around 1.5V.

NiCd batteries output around 1.2V.

Different types of batteries create different amounts of electrical “pressure” as u/ToxiClay put it.

Saporificpug t1_jecuqfw wrote on March 31, 2023 at 2:06 AM

They "do" but they also don't. The voltage wasn't made specifically for the application but is rather what the chemistry can provide.

FartyPants69 t1_jego5fi wrote on March 31, 2023 at 9:48 PM

Exactly, and alkaline cells far preceded Li-ion cells. You could easily make a TV remote today that takes a single 18650 Li-ion cell, but not in 1980.

Since AAA cells have been ubiquitous for decades, and that's what consumers have come to expect, it's going to take a long time to transition everything to something else.

remarkablemayonaise t1_jee2y8r wrote on March 31, 2023 at 10:36 AM

The Lithium cells are rechargeable (typically) or are very specialised single use.

The chemistry of cheap single use cells is based around 1-2V. I'm sure there is some chicken and egg problem where cheap cells could be developed with a higher voltage, but typically higher voltages involve batteries of tried and tested cheap cells.

Pocok5 t1_jefef4t wrote on March 31, 2023 at 4:44 PM

> very specialised single use.

You mean coin cells. CRxxxx coin cells are all single use Li-MnO2.

biggsteve81 t1_jegifwf wrote on March 31, 2023 at 9:09 PM

You can buy lithium AA and AAA cells from Energizer.

remarkablemayonaise t1_jeffktc wrote on March 31, 2023 at 4:51 PM

Fairly expensive in terms of energy density. The alternative are silver based. If you're using a watch for a year or two it shouldn't make much difference.