charge

Step 24: Charge batteries. The cells came around half full and I've driven some laps in the neighborhood. This charger, along with my motor controller, are from a 1981 Jet Electra. The charger is dual output, charging the 12V battery while powering the BMS. The BMS turns the charger off when the battery is full using a relay.  This charger could be put in the trunk and used at charging stations around town with the help of an adapter.  But the charge voltage profile combined with the number of cells I chose only allows for a trickle charge, a C/20 rate. Saving 20% capacity for long life a full charge will take 14 and a half hours. I don't expect to use a full charge everyday. 

I put the charger outlet behind the drivers front wheel, with a fuse at the battery. The location was partially chosen based on body damage in the vicinity.  Creepage and clearance was gained in the 7-pin connector by leaving an empty pin next to the high voltage pins.

After what seemed like forever she reached full charge. The BMS terminated the charge.

test drive

Step 23:  Go for a test drive.  Everything seems to work.  The next step is working out the charging system.

first ride goes to helper

wire batteries up

Step 22:  Wire batteries up.  These being expensive batteries I want to make sure they are protected from damage.  A battery management system (BMS) is employed.  A gracious EV-cohort donated an Elithion BMS needing only minimal additional components.  This BMS monitors voltage and temperature and disables the drive if a cell is in danger of being damaged.  It does the same during charge.  This BMS uses a small circuit board that attaches to each cell, these are daisy chained together and relay data to the BMS controller.  I've installed the BMS controller tucked up under the dash.  I will be able to view the status of the battery pack with my iPhone and a rs232 dongle.

front bank

rear bank, tucked into the back of the
trunk for good weight distribution

BMS controller, rat nests allowed