USB Li-Ion Power Bank with 2 x 5V Outputs @ 2.1A - 5000mAh : ID 4288 : $26.95 : Adafruit Industries, Unique & fun DIY electronics and kits
USB Battery Pack for Raspberry Pi - 10000mAh - 2 x 5V outputs : ID 1566 : $39.95 : Adafruit Industries, Unique & fun DIY electronics and kits
PowerBoost 500 Basic - 5V USB Boost @ 500mA from 1.8V+ : ID 1903, usb boost converter
A large-sized rechargeable battery pack for your Raspberry Pi (or Arduino, or Propeller, or anything else that uses 5V!). This pack is intended for
USB Battery Pack for Raspberry Pi - 10000mAh - 2 x 5V outputs
PowerBoost 500 Basic - 5V USB Boost @ 500mA from 1.8V+ : ID 1903, usb boost converter
Printable catalog (PDF) - Adafruit
USB Battery Pack for Raspberry Pi - 5000mAh - 5V @ 2.1A : ID 1565 : $24.95 : Adafruit Industries, Unique & fun DIY electronics and kits
USB Battery Pack for Raspberry Pi - 10000mAh - 2 x 5V outputs : ID 1566 : $39.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Lipo Shim for Pico
USB Battery Pack for Raspberry Pi - 5000mAh - 5V @ 2.1A : ID 1565 : $24.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Powering 32x64 Matrix with a USB power bank - LEDs and Multiplexing - Arduino Forum