ESP8266 Community Forum

the esp is powered by 3V3 and cheap regulators (like on the d1 mini) are not working reliable with only 5V input, especially during power surges like the one esp8266 produces during boot. You could swap it for a low dropout version or - as I mentioned - try using caps on 5V and 3V3 rail to buffer during these surges (never a bad idea).

at the end I updated my project, more info here:
https://github.com/sblantipodi/solar_station



Sun will hit the box without any shelter, in it there is this circuit with a 18650 battery:



is it dangerous?
will high temp can damage or make the battery explode even if it's inside a box?

A neat looking project.

A note about charging:

LiPo batteries should be charged within a temperature range of 0C to 50C.

So I suppose they will still be working at 50C!

My charging board looks similar to yours and supposedly has

To its credit, the TP4056 uses its extra two pins to handle an external temperature sensor

but I suppose it depends if the board manufacturer uses them. My board has "charge protection" which I assumed avoiding over/under charge but may be temperature as well. Where I live it will not get over 50C and there is unlikely enough sun to charge at 0C.
I have lost the webpage now but battery life is reduced when charging hot - in some cases 40% less cycles at elevated temperature.

If you update your project at any time I would swap out the relay you have for a solid state relay. It takes up less space and should last longer.

Bonzo wrote:A neat looking project.

A note about charging:

LiPo batteries should be charged within a temperature range of 0C to 50C.

So I suppose they will still be working at 50C!

My charging board looks similar to yours and supposedly has

To its credit, the TP4056 uses its extra two pins to handle an external temperature sensor

but I suppose it depends if the board manufacturer uses them. My board has "charge protection" which I assumed avoiding over/under charge but may be temperature as well. Where I live it will not get over 50C and there is unlikely enough sun to charge at 0C.
I have lost the webpage now but battery life is reduced when charging hot - in some cases 40% less cycles at elevated temperature.

If you update your project at any time I would swap out the relay you have for a solid state relay. It takes up less space and should last longer.

thanks for the reply.
I live in Italy and in my are temp goes up to 30-33°C in summer in hot days but if the Sun hit the box,
I suppose that the temp goes a lot higher.

isn't it?