Over the past couple of years lithium batteries have started to overtake lead acid as the battery of choice for EV conversions. There is a higher upfront cost, but the life cycles, weight and range really make them shine compared to any form of LA of days gone by. I have decided to use the same LiFePO4 cells that will power the car to create my 12v battery.
While creating some brackets for a customer I decided to create a few of my own brackets on the CNC machine since I was all setup. The brackets are made from 0.125″ aluminum flat bar with a milled recess to let the screws sit a little deeper so there is still plenty of thread going into each cell.
The cells are configured in a 4s3p configuration with the included orange holders. All connections receive a coating of deoxit during assembly and the custom bus bars join the cells in the required electrical configuration.
The bottom of the battery uses simple 6 hole rectangular bus bars which were very simple to manufacture.
The top of the battery uses some angled bus bars that were a little more difficult to make but well worth it for the easy of assembling the finished pack.
I still need to install the bolts in the outer two plates that will become the battery terminals as well as smaller wires that will connect to the BMS from each group of parallel cells. After I remove the stock battery from the car I will give a size and weight comparison of the new vs old battery.