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Adding a Solar Panel Trickle Charger
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Please be positive and constructive with your questions and comments.

Adding a Solar Panel Trickle Charger

by PaulHollingsworth on Wed Jan 13, 2016 9:16 pm

So please excuse my lack of knowledge as Im very new to this industry...But I am making push button audio boxes that will be housed outside of the enclosures in an animal sanctuary here in the UK.

The set up I have at the minute is.... 3AA batteries hooked up to the Adafruit sound FX board (with built in 2W amps). When a button is pressed it triggers audio that plays out of the 3W mylar speaker. It is all contained within a weatherproof box.

However, to save having to replace the battery's every few days I want to add a small solar panel that will trickle charge some rechargeable batteries. The solar panels that I have and fit perfectly onto my box are (5V 1.5W 300Mah).

I have just ordered the Adafruit USB DC Solar Lithium Ion/Polymer Battery Charger. Would this be suitable to use for this project? And that leads me to my next question...what battery would you recommend to use that will be safe to leave on trickle charge every day...Lithium ion or NiMH seem to be the best? Would I need a diode between the solar panel and battery?

Also is there a way I can make the FX soundboard automatically turn off when the button is not being pressed. At the minute it is constantly using power even when the audio isn't being triggered.

Thank you for any help

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Joined: Tue Jan 12, 2016 8:17 pm

Re: Adding a Solar Panel Trickle Charger

by adafruit_support_bill on Wed Jan 13, 2016 9:48 pm

Our solar charger is for LiPo cells only and the optimal panel voltage for charging is 6v. 5v is the absolute minimum and would only charge under ideal solar conditions. And while I love visiting the UK, I don't go there for the sun. ;-)

If you want to use 5v panels, NiMH cells are somewhat more forgiving than LiPo and the charging circuits can be simpler. I'd recommend having a look at this port from our Evil Mad Scientist friend Windell Oskay: ... -circuits/

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Please be positive and constructive with your questions and comments.