I know these are currently out of fashion but I'm still thankful they exist.
Let's remind ourselves of devices that use(d) these standardized batteries:
- Toys
- Digital cameras
- Torches
- Gadgets like fans
- Wireless keyboards
- TV remotes
Thanks to having a standardized system of batteries,
- You can use the same battery across several devices. This is a no brainer but it's very practical.
- Batteries can charge quicker thanks to being put in a dedicated charger and not being limited by USB cables. (But yes I concede that USB has been updated for faster charging over the years)
- Devices don't have down time when their battery is charging. To charge, the battery is removed from the device and can immediately be replaced with a fresh one.
- You'll never have to trash a device due to an expired battery. Just buy a replacement. And building on this...
- Any improvements in future battery technology can be retro-fitted into your existing devices. And there is a high incentive for future improvement, because...
- An accessible (due to easy replacement) and large (due to many devices) battery market is very attractive to competition.
If you look at the pros I listed, they all happen to be things that would be very useful for electric cars. So I think it would aid the adoption of electric cars if their batteries were standardized too.
I wouldn't say they're out of fashion - a lot of smart home devices are moving away from disposable cell batteries and over to rechargeable batteries.
Do you mean built-in rechargeable batteries? Because that's way worse than removable batteries.
Zigbee smart home devices last a very long time on cell batteries (CR2050 or something similar) that I'm not really worried about those. I've got door sensors that have been going for over 2 years on the same batteries.
No - look at the IKEA smartphone line (TRÅDFRI and the like). They have stopped producing Zigbee devices that require CR2032 batteries and have released larger units that take AAA/AA rechargeable batteries.