Adafruit 2124 Pro Trinket Li-Ion / Li-Poly Backpack Add-On

Adafruit-Pro-Trinket-Li-Ion-Li-Poly-Backpack-Add-On-Adafruit-2124-P-The-Adafruit-Pro-Trinket-Li-Ion-Li-Poly-Backpack-Add-On-has-been-cleverly-designed-to-sit-on-top-of-the-A-href-Catalogue-Search-query-pro-20trinket-amp-filterSearchScope-1-Adafruit-Pro-Trinket-A-and-connect-to-its-power-inputs-with-header-pins-Not-only-does-it-give-you-somewhere-convenient-to-connect-a-battery-it-will-also-charge-the-battery-when-the-Trinket-is-powered-from-its-USB-port-Once-USB-power-is-removed

Price: £ 6.49 from Rapid Online Rapid Electronics Ltd.