Lipo battery recharge with solar cell

Other Hardware General Electronics
1

Hello,

I am working on a prototype of a chicken coop opening and closing system. I have to program a guillotine type door, which opens and closes according to the direction of rotation of the motor driven by relays, in automatic mode. which runs on solar energy.

My internship supervisor had sent me specialized equipment, including:
-a prototype door

  • Arduino UNO boards
  • an LCD display
    -2 limit switches
    -a dual-channel relay module
    -a solar cell
    -4 lipo batteries (including 2 which are now used)
    -several electronic components (resistors, polarizers, etc ...)
    -cables to connect them

Here are the photos of the assembly in question:

And here is a diagram showing the assembly. Note that the "GSM module" part, which is not present on the assembly, should not be taken into account:

image
image894×571 26.1 KB

To power the assembly, I use a 3.7V 1200 mAh LIPO Battery that I plug into this location:

image

The door works fine although I still have to work on it. However, my internship supervisor advised me that lipo batteries should be at least charged with a minimum voltage of 3.6V to work better.

In theory, the solar cell that must sense the outside light to control the door can be powered by the sun to recharge the battery in 30 minutes. To be frank, I have yet to test solar battery charging with the entire hardware as I am working on a prototype.

So, I decided to make a typical assembly comprising resistors, a rectifier diode (to prevent the battery from discharging), the solar cell and the lipo battery in question.

image

I left this assembly illuminated by the sun for 2 hours while the battery initially had a voltage of 3.56V. But 2 hours later, by measuring the voltage, the cell did not charge at all!

I decided to do otherwise and recharge the lipo battery this time with a 5 V generator, a voltage regulator (provided by my internship supervisor) and a mains unit to power the generator:

image

I then recharged the battery several times for several hours (or even overnight), but the battery is either recharged very slowly or not at all.

Do you think I have to do something else to recharge my battery?

Answer me quickly please. I'm afraid my remaining 2 batteries may be burnt out one day.

Thanks in advance.

2

LiPo batteries need to be recharged according to a certain protocol or they will be quickly destroyed.

They are also very quickly destroyed by overdischarge, and need protection circuitry. Some cells come with protection circuitry built in, and if you have one of those, it may need resetting, as it could be preventing you from charging the battery.

There are charger modules designed to work with solar cells, like this one: USB / DC / Solar Lithium Ion/Polymer charger [v2] : ID 390 : $17.50 : Adafruit Industries, Unique & fun DIY electronics and kits

You should do some research on the topic before proceeding.

3

Matching equipment is important in this sort of problem. We really need technical details of the solar cell and the batteries and the other components you're using like what value resistors and how connected. Pictures are not technical specifications.

Steve

4

get a Lipo charger - don't mess around with charging. You can destroy your battery quickly but worth you can light a fire if you are doing stupid things...

There are solar ones - from Adafruit for example or on the store

5

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