I have been running my converted Vectrix with 19 leaf modules for a year now, I installed without a BMS and had balance leads under the seat so I could manually balance when needed.
Unfortunately one cell started going low and eventually lost all charge and couldn't be revived.
I had one incidence when the bike ran low and I had to push it home but I assumed the LVC would protect it from over discharge particularly in the 38 cell setup.
I ended up up having to bridge the bad cell so I'm now running a 37 cell setup using the 36 cell firmware.
The capacity of the pack has dropped significantly and I get 16Ah from it at the most ( the range has dropped from 60miles mixed riding to 25Miles)
I have since read these cells can be damaged when charging in below freezing temperatures, ha s anyone experienced similar?
If so should we be installing a battery heating system when dong the conversions?
Both my LiFePO4 and LiPo (LCO) powered electric rides have battery heating on board, originally due the "do not charge below 0°C!", but with experience much more to do with getting the full power potential out of the battery no matter what the external temperature is. I ride all year round, coldest was -19°C / -2.2 F, but with 20°C / 68F in the battery the bike was happy - not so much the rider :-)
Oh, and please get that dead Leaf cell out of your Vectrix, the chemistry is known for bursting into flames when over-discharged:
EVTV fire while charging a Renault Fluence pack with overdischarged cells in it
2017 Zero S ZF6.5 11kW, erider Thunder 5kW
Thanks MEroller, I understood the leaf cells to be relatively safe, I have bridged the cell so it never receives current during a charge, but now i will get it removed.
Not sure what to do, the bike is still fine for my commute but I miss the extra range I had. I could try and get more leaf cells and build a fresh pack (with heating) or try a different package like 18650 cells.
Do you get the pack really hot? Leaf cells degrade fairly quickly in sustained temps above 90F or so.
No the pack never got that hot.
It did stay out in freezing temperatures down to -7 degrees celsius. I don't believe it was ever charging when the battery was that cold ( I don't ride it in Icy weather).
I try to never charge my VX-1 when the pack's temp (as measured by a cheap remote-probe thermometer I installed with probe resting on top of the pack's orange plastic cover) is anywhere near freezing, but my 2013 Leaf definitely has been charged with its pack temp below freezing. Nissan installed a 300 watt battery warmer in Leafs after 2011 or 2012, but it only comes on when the pack (not air) temp is around 5F. I don't know what to tell you...
That's interesting, if I could start over I would install some terrarium heat pads in the battery box.
I have a leaf too (2013), I'm surprised they let it get that cold before they heat the battery 5F is -19 Celsius! I usually preheat the vehicle when it's plugged in so I assume that helps warm the pack too.
TBH, considering the V's pack is so small (relatively speaking) it would make more sense to always charge it as soon as you get in (when the pack is still warm from riding) rather than doing a timed event later (when it might be freezing) to save money on electricity costs (assuming you have a cheap tariff at night etc). The cost of installing heating might be significant. That said, I just used a self-regulating domestic electric (bed) blanket on one of my conversions which worked well and cost little.
Regards, Martin Winlow
Isle of Colonsay, Scotland