I have a fun project I want to do. It's really simple: I want to power a long LED strip using a bunch of 18650 batteries. The batteries I use are 4.2v fully charged and about 3.5v when discharged (I don't want to push them further down than this).
The LEDs are WS2812b and they work from 3.3v to 5v easily. I successfully power 10 of them with a single 3.3v signal from my ESP8266 and they're bright enough.
Now, what would be best?
- Wiring 2x 18650 in series, making a maximum of 8.4v and a minimum of 7v, then use a buck converter to make it 5v all the time.
- A single 18650 battery at 4.2v maximum and 3.5v minimum.
I will make a bunch of these in parallel, so I have more current to run the strip for a longer time. Option #2 would definitely be a better option for me, as it doesn't take that much work.