Comment on Coin-sized nuclear 3V battery with 50-year lifespan enters mass production
sugar_in_your_tea@sh.itjust.works 2 weeks agoWhy not?
A CR2032 has 235 mAh, which I believe Casio watches use, and their batteries last 5-7 years. So, if we divide that out, that’s something like 5-6 microamps (235 mAh / 5 years / 365 years / 24 hours * 1000 = 5.36… microamps). Converting this to watts @ 3v: 15-18 microwatts.
I think that math is correct (this question reaches a similar conclusion), and it leaves some headroom as well.
If you remove RF from the equation (Bluetooth, WiFi, etc), you can get some very low power draws. If all you’re doing is sampling temps or something, you could send an update periodically over serial or something and fit under 100microwatts or so. You could probably even do RF if you have a large enough cap and send once it charges.
ExcessShiv@lemmy.dbzer0.com 2 weeks ago
CR2032s are used in many things that require significantly more power than that, and this cell is absolutely unfit for almost all other uses than barebones old school digital watches.
sugar_in_your_tea@sh.itjust.works 2 weeks ago
Sure. I’m not saying it’s a drop-in replacement, just that it has a number of applications. A simple digital watch or even a bare bones IOT device (with periodic serial signaling) could work well with it. You’d essentially set it up once and you’ll forget it’s still there many years later.