Espruino WiFi Board + Battery + USB Charging

[espruino-discuss3]

Posted at 2016-09-29 by Vanderlin

I am wondering the possibility of add a Lipo Battery to power this board and using the existing usb plug to charge the batter when connected. Similar to how the Adafruit feather m0 works. Any thoughts on this?

[gfwilliams]

Posted at 2016-09-29 by @gfwilliams

Hmm, that's tricky since USB power on the Wifi board is connected straight to the main power pins.

The easiest would be to get a 3.3v switchmode supply and power the 3.3v line from the battery via that. You could then power the lipo charger from the Wifi power pin.

The other benefit is you can run the battery down further. If you'd just plugged a lipo in my guess is the Wifi would start to play up long before the battery was fully empty.

[gfwilliams]

Posted at 2016-09-29 by @gfwilliams

Looks like ESP8266 will run down to about 2.5v so it's not too bad, but you'll still get better battery life with a good switching power supply.

[espruino-discuss3]

Posted at 2016-09-29 by Vanderlin

SO I can just connect a LiPo like this to the +/- on the board and the USB will charge?

[espruino-discuss3]

Posted at 2016-09-29 by DrAzzy

Dear god no. You should never charge a LiPo battery without a charge controller - those have measures in place to prevent overcharging - that's very very important with lithium batteries, since they can catch fire when overcharged.

I think your best bet is what @gordon said. Note how he mentioned using a LiPo battery charger.

[gfwilliams]

Posted at 2016-09-30 by @gfwilliams

You could easily use something like this: https://www.adafruit.com/products/2465

The only problem with that is you don't get the USB data connection while the device is charging.