LiFEPO4 battery spacers and Daly BMS mounts

thingiverse

A friend is retrofitting his trailer coach to have LiFEPO4 battery packs instead of the standard lead-acid batteries. He came to me with a challenge: assemble four 3.3V 280Ah cells (in series) and a Daly BMS-250 (Battery Management System) into one "battery pack", that is portable and self-contained. This Thingiverse entry is my answer to that challenge. It contains all of the parts to space the four cells apart (for airflow), give them feet to sit on, edge guards, terminal guard on one side, mounting brackets for the BMS to slide into, BMS terminal guards with sensor wire guides, a locking part (to secure the BMS) which accepts a 1/4x20 0.50-0.75" long plastic bolt (or M6x1.0 12-16mm plastic bolt), and accommodation for a 2-inch nylon carry strap. The terminal guards can be printed in tri-color thermal-sensitive PLA, which will change color at 88F and 113F. So, at a glance, you can tell if your battery pack is overheating. The middle BMS bracket and locking part is intended to be threaded together with a threading/tapping tool. The whole pack should be taped with fiberglass-reinforced packing tape, diagonally (both ways) on each long side, across the top longways (in the middle), and across the bottom longways (along each edge). With the spacers in place to entrap the cells to prevent lateral movement, this taping procedure is sufficient to secure all of the cells together. The feet, edge protectors, and BMS mounts are designed to accept a two-inch (2") nylon carry strap (63 inch lashing strap with velcro rated for 150lbs) wrapped around the whole battery pack (which itself is 50lbs). This provides a grab point on the ends of the battery pack, and provides redundancy to the packing tape. Pics of the battery pack assembly will be uploaded as a "make" of this thing. Stay tuned!