Switching between two energy sources


I am quite new to the Arduino world and I'm currently building a project in which I would like to switch between two energy sources (induction when near base (Inductive Charging Set - 5V @ 500mA max : ID 1407 : $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits) and solar when induction is out) supplying a Lipo Charger (I am thinking of using this USB/DC Lithium Polymer battery charger 5-12V [3.7/4.2v cells] : ID 280 : $17.95 : Adafruit Industries, Unique & fun DIY electronics and kits) which continuously recharges a battery (6600mAh, 3,7V) supplying an Arduino Nano. The solar panel I use is 5V 2W.

My first lead was to use power MOSFETs but the folks at Adafruit advised me to simply use diods instead to protect each input. Which kind of diods should I use?

Would this work with the attached setup? It may sound like really stupid question but I really want to be sure of what I'm doing.

Any help or suggestions would be welcome! :slight_smile:

Thank you very much to all


That sounds plausible; I see no reason that won't work in concept, except you've got too many diodes and they're hooked up wrong.

Remove the diodes on ground.

On + side, turn the diodes around, they're backwards.

Use Schottky diodes with an appropriate current rating for your anticipated use.

Thank you so much for you quick and clear answer!

One last question, will the circuit still be ok if I connect two chargers in parallel as on the schematics attached?

I'd rather put the two batteries in parallel (uh, make sure they're at about the same state of charge when you do this, so there's not current flow when you wire them up). I'd be concerned about the two chargers each having a slightly different idea of what exact voltage to output, and fighting with eachother.

In fact I forgot to say that each charger supplies a different load! (one supplies an Arduino Nano and the other a Radio Transmitter).

Would it be good then ?

Thank you so much DrAzzy