I made this to manage the batteries for my Blade Nano QX quadcopter. The slots are designed so the 1S LiPo batteries can be inserted in either direction. That way when I discharge a battery, I can put the battery back in the organizer in the opposite direction. The organizer I printed for myself also has a slot that fits a USB LiPo charging unit.
This is a customizer, so you can choose the number of 1S LiPo batteries and whether or not to include the USB holder.