Adapter for connecting ToolkitRC M7 charger with a widely available Dewalt 4ah battery. Printed in PLA. Item sold without battery or charger.
 
I chose to use Dewalt 4ah battery as a solution for this method of charging because the battery is cheap, have a built-in balance charger and deep discharge protection. A big supply chain spread through World provides easy access to batteries, which provides a backup when needed.