If you fly multirotors, you may run into the same problem that I do -- sometimes you just don't get to fly all of your packs. Storing batteries at full charge is no only unsafe, but also damages your precious packs. I created this box to work in conjunction with the AOK Lipo Battery Balancer to get my packs down to storage charge. I purchased mine at Banggood (https://www.banggood.com/AOK-Black-3-In-1-150W-Lipo-Battery-Balancer-LCD-Voltage-Meter-Tester-p-1062446.html?rmmds=search), but they are also available on Amazon, and probably eBay.
You will need:
(4) 3mm x 16mm (12mm will work) Flat Head Cap Screws
(6) 2.5mm x 12mm (2/2.5mm x 10mm will work) Socket Head Screws
(6) 2.5mm nuts (I used ones with nylon inserts)