DIY Solar Powered Weather Station
*Please Note! For this diy solar powered weather station you will need a different article on this website as a prerequisite for this project. This guide shows you how to add the solar portion. Follow this project and complete it first: Click Here
Features:
Never have to change the battery again.
Automatically disconnects power to protect the battery (Mine has never had to disconnect as it has enough backup power to last for weeks of dark winter days). If you have any concerns with this it’s very easy to just add more 18650 batteries in parallel to the 1 that I’m using.
Automatically turns back on once the sun comes out and the batteries charge back up.
DIY Solar Powered Weather Station Parts List:
18650 charge protector
18650 Li-po battery
18650 Li-po battery holder
5v Step Up – In the photo I used a small stepup that I don’t recommend as they tend to fail, please use the one that I’ve recommended in the link “5v Step Up” as they’re now my go to unit and are awesome.
5v Solar Cell 500mah
Wiring
In photo 3 the solar cell wiring is plugged into the bread board first in my example. I did this because it gave me the option to disconnect the solar cell and replace it easily but you don’t have to do this.
How to Connect the Wiring
The solar cell is connected to the 18650 charge controller at the end that has the micro USB. In photo 3 it goes from a red/white pair to a blue/white pair. It’s marked clearly with a + and a – where the wires connect. I only just realized that the 18650 charge controller will keep your solar cell safe if you have only one solar cell. The voltage will not flow back through to the solar cell and you do not need a blocking diode. If you have two solar panels in parallel you will need a blocking diode on each solar cell you add into the project.
18650 Charge Controller Wiring:
You’ve just connected the solar cell and now we’ll hook up the battery box. The two wires coming off the battery box go to Voltage1 (photo 3 and is the top rail). The top rail is then connected to the 18650 charge controller inside pins. You’ll see them on the board with labels of B+ and B- for battery positive and negative. Those solder pads will block electricity if the 18650 battery gets too low 2.7 volts I believe. They will reactivate when the solar cell charges them up to about 3.2 volts. Those pads will also not let the voltage from the solar take the 18650 batteries too high and will cut off the solar when the battery reaches 4.2 volts. The red light that indicates the solar cell is charging, will turn blue when the battery is full. They’re an amazing add on to any project. The outer pads are labelled out+ and out- and will be connect to Voltage2 (look at photo 3 its the bottom rail).
5v Step Up
On your 5v step up the bottom rail in photo 3 Voltage2 is connected to the “in” side of the step up. On the board it will be labelled IN+ and IN- then you connect the GND and 5V while leaving d+ and D- alone. Those inside solder pads will only give you the voltage of the IN side and we don’t use them in this project. Connect the GND and 5V on the step up’s out side to Vin and GND on your NodeMCU.
Deep Sleep wiring:
You’ll notice a green wire in photo 3 going from RST (beside GND) to D0 on the NodeMCU. This makes a connection to wake the NodeMCU up and will save a lot of power. This is really important as it’ll save on the use of the battery overnight. It’s always better to use software to save power instead of just adding more expensive items like 18650 cells.
That’s it! If you have any comments or questions and what some help with your project I LOVE a good challenge. I’ll help you develop what ever you need without charge. But I’ll most likely end up creating a tutorial for my efforts.