Adafruit PowerBoost 500c - Rechargeable

Sure, you can get regular "powerbank" modules to recharge your dead electronics, but Adafruit has engineered this really well thought-out rechargeable 5.2V power module. This is like their PowerBoost Basic, with LiPoly charging circuitry added in.

Plug your LiPoly cell into this, then power up your load (like your Raspberry Pi). When your battery power starts to drop, plug in the microUSB charger to the module and recharge your battery at 500mA all while keeping power to your project! It's a mini-uninterruptable power supply (assuming your load pulls less than ~300mA).

First of all, why 5.2V instead of a solid 5V? The extra 0.2V will adequately compensate for any connector and cable losses between this module and the project you are powering. Even so, feeding 5.2V into a "5V" designed device is quite safe. Feel comfortable using this to power your Arduino / RaspPi / BeagleBone / etc...

Specifications:

• 2ASwitching capacity. This means you can get at least:
  • Tested to be able to source over 1A from a 3.7V LiPoly/Li-Ion (of sufficient discharge capacity)
• 3.2V Low battery indicator, which is ideal when using LiPoly/Li-Ion cells
• Yellow "Recharging indicator", Green "Fully Charged" indicator
• 500mA charge current Apple/IOS resistor settings
• Full pin breakout for the battery, enable, control, and power out lines for embedding onto a breadboard
• 90% operating efficiency in most operational conditions
• 5mA quiescent current (doing nothing), and 20uA current in disabled mode
• Included optional USB A jack for turning it into a USB power-point
• Includes footprint for using a 3.5mm 2-pin terminal block
• 22x37x2mm (0.9x1.5x0.08"), 7mm high (0.3") with JST header
• 4g