Solar panel of 12v compatibility with Mayfly

Hi

I designed my datalogger using Mayfly with a 4000mAh 3.7 Li battery and a 0.75W 6V solar panel.
Sleep mode was added.
The battery can last for 30 days (4.13V drop to 3.7V) without solar panel. If solar panel added, It can provide enough power even during cloudy day.

10W solar panel may be too much. But it is really depend on the power consumption of your system and the solar radiation shined on your system.

The mayfly lipo charger MCP73831 only accept input voltage from 3.75V to 6V. You cant connect a 12V solar panel to it.

If you want to do it, I suggest you connect the solar panel to a solar controller(charging a battery) and the 12V output connect to the external 4-12V input of Mayfly.

The mayfly lipo charger MCP73831 only accept input voltage from 3.75V to 6V. You cant connect a 12V solar panel to it.

If you want to do it, I suggest you connect the solar panel to a solar controller(charging a battery) and the 12V output connect to the external 4-12V input of Mayfly.

I dont suggest you to connect the solar panel to Mayfly and battery directly.

ChanCafun is right, you definitely don’t want to connect any panel to the Mayfly’s SOLAR jack that has a voltage higher than 6 volts. I wrote a post about solar panel options earlier this year: https://envirodiy.org/topic/dying-batteries-in-winter/#post-2051

Since that post, we’ve released the Mayfly v0.5 that has the option for directly connecting up to 16v on the External Power input pins. But unless you’re leaving the logger on continuously and powering some current-hungry sensors, you should be fine with a 3.7v Lipo paired with a 3.5W, 6W, or 9W panel, keeping in mind that anything over 3W is unnecessary if you’re in direct sunlight (see my explanation in the post above).