Lux ac battery controller

chainreaction

The first time we had a sunny day last week, I didn't overnight charge the batteries, so over the 6 hour cheap rate window the AC charge enable was on but set to charge if batteries dropped below 25%. Charge priority set for the cheap rate window so the batteries didn't discharge. SOC dropped 12% over the 6 hours. Alerted to this it's been happening between 23.30 and 02.00 after 02.00 batteries go on charge, just wasn't watching it close enough probably 3-4% loss.

newbuilder

Like this when force AC is on?

newbuilder

And one showing the full range of off peak after charge

chainreaction

Yes very similar, didn't overnight charge my batteries earlier today battery SOC dropped from 54% (midnight) to 43% at 05.30, see screenshot from today

newbuilder

Yeah keep me updated and send the file over if it works

chainreaction

Will do....

ianatkin

This shows the strange behaviour I'm getting at the moment.

First area is a sudden jump in SOC in charging and stopping short of 100% (AC charge was set all the way to 5:30).

Next area shows my SOC dropping more than I'm used to once the batteries have been topped up to 100% by solar by mid morning, followed by them deciding to top back up, holding 100% for a good hour then starting to fall of their own accord.

The third area shows the SOC decreasing in an irregular way even with very little discharge into the evening...


I'm thinking my only option is to disconnect everything and reconnect one at a time and make sure it's brimmed before connecting all six back together again?

I wonder if this behaviour could indicate one or more of the three used batteries I added recently has a much worse SOH than the rest and it's confusing the BMS on the master?

newbuilder

The install rate is normally 45% SOC so maybe bring the stack down to that and then check what ones need a manual discharge to that.  When looking on the BUS it didn’t show any individual cells with vastly different volts? 

ianatkin

newbuilder said:

The install rate is normally 45% SOC so maybe bring the stack down to that and then check what ones need a manual discharge to that.  When looking on the BUS it didn’t show any individual cells with vastly different volts? 

I'll give that a go when I feel like spending a while crawling around in the loft again! 

I checked all the cells on all six batteries when I upgraded the firmware, there were no issues at all, no more than a small number of mV between any of them. 

newbuilder

This was my fault.