Solar PV-lithium battery phone charger

Hello,

I was looking to implement a phone battery charger which uses a 6000 mAh lithium battery as a power source. This battery is charged by a solar panel and I will have WS2812B LEDs to indicate battery state of charge whenever a button is pushed.

I will implement the LED-button algorithm on an arduino nano along with the charging circuitry on a printed circuit board and I plan on enclosing everything in a bamboo wooden enclosure with a carving on the back allowing for the solar panel installation.

My question is: would I require some special phase change material, insulator, or separator between the solar panel, battery, arduino, and the rest of the electronics to prevent malfunctions or possibly overheating of certain components - imposing a risk?

Note: The enclosure will be kept indoors in a ventilated area where the only exposure to external elements will be from the window for the solar PV to generate energy.

Any recommendations or references for design drawbacks that may occur are very welcome.

Thank you

Potentially the most serious problem is overcharging the battery.

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