I did manage to conjure some pretty impressive sparks as well when moving the then assembled, but nearly empty pack. I guess it just goes to show how much power these cells hold and a healthy reminder not to handle them carelessly. Oh and they do melt metal quite handily.
maanantai 30. heinäkuuta 2012
I finished bottom balancing the cells between 2.7 and 2.8 volts just before midnight and left the pack charging overnight. After a night of nightmares regarding cell explosion, single cell overcharge and irrational fear of pack accepting only a fraction of designated charge I'm pleased to report that all is well. The pack read a voltage of 80.5 V, amp hour count of 42.9 and cell voltages varied from 3.32 to 3.38. In fact 42.9 is a bit more than the 40 Ah specified for the cells. The reading may not be completely accurate due to Cycle Analyst running, the Contactor also drawing some power and shunt not being exactly calibrated. It is however a very good result. Bottom balancing seems to really work and I didn't spend the whole of yesterday in vain.