I want to create a clock using neopixel ring (similar to this project). But I'm not gonna power up all pixels at once (maximum of 10 pixel at a time) And also I want to use a NodeMCU as its controller. Can I power this project using one 18650 battery or a Li-Po (3.7V) as power source? (combined with a charge module, a 3.3V regulator for connecting it to the NodeMCU and (?) a 5V dc booster for pixels)
Put together a table for the devices. Write down both voltage and current need for each component. That is not so difficult. Helpers shouldn't need to do that.
And what it the point of that?
What makes you think that?
do pixels use energy even if they are turned off?
Very well. The NeoPixels/ WS281x use just under 1 milliamp when "turned off" - coded to all zeros.
So the project you cite with 96 LEDs would draw some 95 mA even if dark.
The trick question here is - how would you propose to "power up" only 10 pixels at any one time? Let's say you have eight groups of 12. You wish to switch the 5 V positive supply to each of these eight groups alternately. Just how are you going to do that?
Since you cannot drive data to the pixels when they are powered down, you will have to have eight separate data lines for these separate groups and you are going to have to code accordingly.
This is getting to be quite an involved project.
A nodeMCU can be fairly power hungry, and a LiPo (an 18650 is also a LiPo) drops to 3.7v which is not easily converted to 3.3v, you should use a buck converter. So that means 2x Converter 1 for the LEDs and 1 for the nodeMCU. Now not lighting up more than 10 pixels at a time is going to save a lot of energy, and not lighting them up to full brightness is going to save even more, but it will still need to be recharged quite often. How about just using a constant power source ? The clock doesn't need to be mobile, so why would you want it battery powered ?