Charging 3.7V 500mAh Li-ion Batteries via solar Moderators: adafruit_support_bill, adafruit

[quantumbozo]

Hey guys,
I'm looking to charge 3.7V 500mAh Li-ion Batteries via solar panel for a project. I'm looking to see if this is feasible?
I'm going to be charging these batteries https://www.adafruit.com/product/1578. The solar panel will be attached to a microUSB, which I will run through this https://www.adafruit.com/product/1905.
My question is, is this safe? If this isn't feasible, can you suggest another setup I can use to do this?
Thank you so much.

[adafruit_support_bill]

That should be safe. But it probably won't work very well. Solar power is quite variable and most charge controller chips work best with a steady input.

We have some chargers specifically designed to work with solar panels.
https://learn.adafruit.com/adafruit-bq2 ... -3071654-4
https://www.adafruit.com/product/4755
https://www.adafruit.com/product/390

However, for a small cell like that, you need to keep the charge rate to 500mA or less. Both of our solar chargers are configured for 1000mA by default. But you can adjust the output down to 500mA : https://learn.adafruit.com/adafruit-bq2 ... -3071584-6