2x2 18650 Cell Holder

thingiverse

A 4S 2800Mah Battery pack made up from Molicel P28A cells that have a 35A discharge rate for my electric powered control line model Super Combat Streak. I use "BGA" size solder wick for the inter-cell connections and 16ga battery lead wire to an XT30 connector. The spacers are a slip fit to the cells. The end caps keep from shorting on things. I use Molicel P28A cells. These are 2800mah capacity with a 35A max discharge rate. I solder all battery and wire connections. I use size "BGA" solder wick for the battery interconnections. I use 16 gage Castle Creations wire leads terminating to XT30 connectors. All soldering is done with a 40watt iron and a chisel tip. 1st-I clean each battery terminals with a few swipes of scotch brite and then wipe 'em with a bit of lacquer thinner. 2nd-I pre-tin the cell terminals with a bit of 60/40 rosin core solder. It only takes a few seconds to achieve an acceptable blob. 3rd-I assemble the 4 batteries into the 3D printed cell holders that allow a slight press fit onto the cells. The back and front spacers are different from each other as the front requires an opening to allow the 16ga leads and balance tap wires to exit. They also allow cooling air to circulate between the cells and allows thru the center air flow. There is also trenches for the interconnect straps and clearance for the balance tap wires. The cells are only slightly warm after a 5 minute flight consuming @1800mah (@22A average). 4th-I solder 3/4" long pieces of the solder wick to the cells. 2 straps on the back end and only 1 required on the front end. 5th-I then solder the battery leads onto the plus and minus terminals that already has the XT30 connector attached to them. This reduces the chance of a short circuit. 6th-I then solder the balance leads to each cell using the positive terminal "side" when possible. This allows a quicker easier solder operation. 7th-I then get my voltmeter out and verify the balance tap wire sequence and the polarity of the XT30 connector. 8th-I then use medium CA to attach the front and back end caps. These keep the connections safe from shorting on something.