This blog documents the restoration, and conversion, of a 1965 Humber (Singer) Vogue to a fully electric vehicle. The Vogue will be powered by an 11kW(modified), 3 phase industrial AC motor, controlled by an industry standard Variable Speed Drive (VSD) or Inverter. To be able to produce the 400 volts phase to phase the VSD will need about 600 VDC of batteries. A big thanks to the contributors on the AEVA forum:

Sunday, February 20, 2011

Battery Pack Balancing

After around 9 months of storage of my battery packs, and following the controller auto-tuning saga mentioned previously, I began the task of balancing up the cells within each of the packs. The charger and BMS within the packs handles balancing after charging but it is less stressful on the packs to do it with an external current source. I charged each pack normally then when the BMS cut out due to a cell going to 3.9 volts (usually at a pack voltage of between 54 and 55 volts), a little external device switched to a 180mA current source. This is the same amount of current that the BMS can bypass across each cell pair. It took somewhere between 24 and 50 hours to get the packs to 58.3 volts. It took from 21st January to 12th February to balance the 12 packs. I did some work on the dashboard (yet to be blogged) during this time.

My device in the piece of black heat shrink dangling below the pack being charged.

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