I have noticed after pulling apart my 9th vectrix battery an above average failure rate on the cells attached to temp sensors
I have no theories as to why this may be, but after 9 batteries I'm getting past the statistical anomoly stage
has anyone else noticed this?
I agree, I have done 3 batterys now, and there are certanly a large number of them dead with a temp sensor. I just think it applies to all center pac cells..I still havent found a dead cell in an end position..
That sort of sounds like it was the other way round: Vectrix possibly placed the temperature sensors in the battery areas that are most prone to overheating?
My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW
I did not find this effect in the "Vectux" battery. See http://visforvoltage.org/forum/5052-uneven-distribution-weak-vectrix-cells-within-battery-pack-why
However, I analysed the battery before any cells were dead, and you have counted dead cells. That might be part of the explanation, but I doubt it.
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There might be a way to differentiate between effects due to cell location and effects due to temp sensors:
In the 8-cell modules there is no centre cell. You can therefore compare the failure rate of those cells located next to temp sensors with the failure rates of the cells with temp sensors in the 8-cell modules. That would be easier than the more detailed analysis suggested below.
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Did you keep records? It would help to see the data to get a feeling for possible explanations.
I think that if the "centrality" of a cell is causing failures (due to higher temperatures or whatever), then I would expect a normal distribution of cell failures, with the peak of the Bell curve over the middle of a module and the tails towards the ends of the module.
If the temp sensor was somehow to blame for failures, then I would expect an even distribution over the module, except for a spike at the temp sensor cell position.
This information may be used entirely at your own risk.
There is always a way if there is no other way!
regrettably no, I didn't keep detailed records.
I just marked the cells that were bad, but not if they had a temp sensor attached
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Just out of curiosity, do you remember if any of the drilled and tapped bolt-heads
ever snapped off during pack dis-assembly or re-assembly?
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
I've done the same thing and over torqued one, they snap remarkably easily. I had the guys at work easy out the remains of it and i fitted a new bolt.
I'd love to replace all the bolts to be honest as they seem really soft !