I collected my new batteries, They are used identical Turnigy LIPO’s 5S1P’s from Steve’s Electric MX5 which he is sadly breaking (house purchase forces cashing in of assets me thinks) still I intend to purchase the Motor and Controller from it to convert my RX8 so it is not all bad news.
Carried on testing the new cells same as before
1) Charge to 4.2v
2) Discharge and graph
3) Check graphs and discard any bad one’s (Steve assured me there should be none)
4) Balance good cell packs to 3.8v and fit them in 3rd and last battery box
Unfortunately when we pulled the batteries from Steve’s car we noticed an imbalance on some of the cells in a parallel block so all of them were showing cell 2 as being down at 1.5v and after testing and graphing these cells 8 of them showed an imbalance after a single charge and discharge and graph, and the failed one was done at 0.8v on cell 2.
I pulled these 8 to one side and collected another 6 from Steve to cover any possible bad ones (only needed 6 as Steve had given me 2 extra to cover the potential bad one in the first place, And as I completely forgot to take the bad ones back to him when I collected I now have all of these extra ones to find 6 good cells from to fill the last 6 slots in my last battery box (getting close now)
Last night (24th April) I fitted all the cells in the last 3rd battery box and packed them ready for wiring, just need to charge/graph and balance 6 more of the 14 cell packs I have and fit them before I can wire up the last box and close the lid.
As soon as this is done I will drop the remaining 8 iffy cells back to Steve, There is really only 1 definite bad cell in this 8 but I want to make sure the 6 I fit are all good and well balanced cell packs, after all I have just spent 2 months testing every single cell and balancing them perfectly.