Battery cell voltage

I appear to have one cell reading lower than the rest, anything to be concerned with?

Those all look remarkably close to me. I had problems with my system, where the variation between the cells was causing the battery management system to put it into a self-limiting mode when attempting to charge at full rate. But that was exhibiting variations of a couple of hundred millivolts.

I wouldn't worry about this, as long as it appears to be behaving correctly in its charging and discharging behaviour. I'm no expert, but I'd say your readings look very normal. There'll always be one or two cells 'leading the way' when charging or discharging.

Support have/are carrying out a battery calibration on it, due to the cells having fallen out of alignment. Hopefully this sorts it out, but looks like cell 8 is is not playing, currently its at 3.374 when most of the others are at 3.341

Fridgeman From what I've read, when there's a weak cell, it tends to lead the pack whether charging or discharging. I'm keeping an eye on cells #5, #8 and #13, but the spread doesn't seem to have got too wide yet. (3.246 to 3.264)

ive now got 3.374 ish on most cells but 3.411 on cell 8 now

DD Same cells go about 20mV out of alignment on mine.

I'm pretty sure the chip on the BMS is only accurate to 20mV so you'll likely never get it perfect.
The balancer itself may have even higher thresholds.

Well its just finished the calibration and ive instantly had a BMS overvoltage notification, cell 8 now down to 3.29. Emailed support back to see if they can do anything else

Fridgeman the balancer will have a threshold voltage where it actually operates. This is unlikely to be the voltage the battery idles at even when fully charged.
What you might find is repeatedly force discharging (not much, few %) and then force charging to full gradually pulls this cell up to the rest using the balancer.
I had a lazy one, but like it, I too was lazy, and so I just manually forced charge that one cell up from a PSU, (although it wasn't a GE pack and I don't really recommend doing it as your warranty will be utterly gone)

hoggy Yeah, i think i'll let Giv look into it rather than killing the warrenty or myself