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 use rechargeable interchangeable batteries wherever I can, but I recently ran into some issues with an ultra-cheap BDC "massage" pillow. The OCP in the batteries was getting triggered and the motor would stop and start spinning for 10 seconds at a time. Tried to add small value resistors and capacitors to it but nothing worked and I had to get a pack of alkaline. Only now do I remember I have a bunch of spare 18650s and USB battery charging boards that I could've retrofitted!
Next time add a capacitor instead of a resistor for this
In series or parallel? How would it help?
In parallel. The capacitor smooths out the power and keeps it from spiking and shutting down over and over.
A resistor (in series) would help too but might restrict power too much to work well.
No harm in adding a capacitor.
On almost all my projects the weird behavior has been solved by throwing a cap in it