Add a rechargeable LiPo to Arduino micro project

Question

I'm somewhat confused by the various options, hoping someone can clarify which breakout board I need. I want to build a prop that drives a bunch of Neopixel sticks. It should:

• have a rechargeable battery
• work with an Arduino micro
• be able to charge over USB when plugged in to a computer
• be able to get new firmware over the same USB cable
• be able to drive the LEDs directly off the battery and not just through the Arduino voltage regulator (there may be lots of them).

Am I correct that I could do all that with this LiPo battery charger?

Are there other options that would be better?

Answer 1

Here is a product that fits the bill: Lipo Rider Pro

I'm using the older generation (not Pro) and it does work great. USB in for charging a 3.7V LiPo cell, and passes through data with a 5V feed to USB out (buck converter from LiPo or your USB power). It also has a connector for a solar panel to charge with, though I don't use it. And it even has an ON-OFF switch for the battery. The linked page claims 1A power out.

This way you can plug your PC to the LiPo Rider, it charges the battery and you can use the COM port with the Arduino if needed. Disconnect the PC, and it powers from the battery.

Answer 2

OLD ANSWER: There does not appear to be a USB pass through in that circuit, so you would not be able to download to the Arduino while you are charging (it's not clear whether you intend for the 'same usb cable' to mean the 'same usb cable at the same time'). If you want to design your own solution, there are a lot of simple USB based single cell lipo battery charging ICs (MAX1551, MCP73811...many others).

EDIT: I didn't realize the Arduino micro is a 5V device, the part linked would not work. A single lipo cell only provides up to 4.2V (but realistically more like 3.9V under load), so there is no linear regulator which can provide the voltage the Arduino needs. So either you need to step up the voltage from the battery with a switching regulator, or you need a 2 cell battery/charger (which would need a step up anyway to be able to charge from USB). A simple solution would be to use https://www.sparkfun.com/products/11231, which integrates both the charge controller and a step up regulator. It also does not pass through USB, so you can't charge and program at the same time either...