Hello, I have a solar panel that is rated at 3v 2A in Full Sun, I assume the voltage is open circuit.
If I'd like to make a li-po battery 18650 cell charger but the challenge is that I sort of have more amps than volts.
Is there a way to trade amps for more volts at such low parameters? In a simple DIY way? I'd prefer to avid buying already made products since I want to learn.
I can not use 2 panels in series or other type of panels. The panel I mentioned is the one that I must use. Nothing else.
The li-po is a 18650 cell 3.7v @ 1500mAh. The device powered by this battery consumes around 3mAh.
The solar panel/cell will not be on the sun constantly all the time. It will be on a coffee table that get's hit by the sun ~2 hours a day if there is any and the rest of the day is normal light coming from the windows illuminating the room.
I assume you have read lots of warnings on charging these batteries and the possiblity of fire if done incorrectly.
You could use a 12 volt panel and switchmode regulator to reduce it to the voltage required. The regulator should be able to convert the higher voltage lower current to low volts high current.
weedpharma:
I assume you have read lots of warnings on charging these batteries and the possiblity of fire if done incorrectly.
You could use a 12 volt panel and switchmode regulator to reduce it to the voltage required. The regulator should be able to convert the higher voltage lower current to low volts high current.
Weedpharma
Yes, I've read the warnings. Over and under charge Dangers.
I CANNOT use a different panel.
Is there a regulator that changes low voltage high amps to higher volts with less amps?
Boost converters with Solar panels are problematic when the solar panel isnt in full sunlight, in that the boost converter wont reliably start.
This is because Solar Panels act as current sources and when loaded by the boost converter trying to start the voltage from the solar panel collapses.
Boost converters are more suited to voltage sources like batteries.
The normal practice with a Solar Panel is to charge a small battery and run the boost converter from the battery.
mauried:
Boost converters with Solar panels are problematic when the solar panel isnt in full sunlight, in that the boost converter wont reliably start.
This is because Solar Panels act as current sources and when loaded by the boost converter trying to start the voltage from the solar panel collapses.
Boost converters are more suited to voltage sources like batteries.
The normal practice with a Solar Panel is to charge a small battery and run the boost converter from the battery.
I've had that problem with the boost and solar panel. I rather avoid that.
So do you think that I should charge some 1.5v AA batteries and then from there use a booster converter connected to a charger controller for Li-po's?
Its very hard to know what a good solution to your problem is without knowing more about the Solar Panel and how much power it can reliably generate under the conditions you are using it under.
Id be inclined to junk the Lipo battery altogether and just use a C or D size Nimh battery directly charged by the Solar Panel which drives the boost converter which powers your project.
NIMH batteries can be overcharged provided that the overcharge current is C/10 or less, and they wont suffer as much if they are flattened as the Lipo battery.
You dont need a Lipo battery for a 3 ma load.