18650 2x2 Battery Holder

Here is a 18650 LiPo Battery Holder that can hold 4 18650 batteries in various configurations. You can connect the 4 batteries either all in series 4S1P, all in parallel 1S4P or 2 in parallel and then those 2 sets in series 2S2P. It uses 8 m5 x 20mm hex head bolts as contacts to the battery terminals, I would recommend filing / sanding the heads of the bolts smooth for the best contact because the heads of the bolts often have little numbers or letters stamped on them for identification purposes. The main screw that runs through the middle of the holder is 1/4" x 3.5" Phillips head bolt with a matching 1/4" nut on the opposite side to thread into. For connecting the m5 bolts to each other for whichever wiring configuration you desire I used 1/16" thick by 1/2" wide aluminum flat stock that I bought in a 36" length and cut down to pieces that were 1.25" long. A hacksaw or diagonal cutters can be used to fairly easily cut the aluminum pieces. The aluminum bar can be found at most hardwar