Random discharge following slave upgrade

[Giggermatt]

Hello everyone

I have had an EVS2900 v2 system consisting of a master plus three slaves in operation since June, and performance has been near faultless. I also have a 5kw PV set up.

I decided to have an additional slave installed, and all appeared well until the evening of the installation day, when the SOC dropped from 50% to 10% over about 15 minutes. I do have a forced grid export setting that cuts off at 60% SOC but this had already functioned correctly earlier in the afternoon. I had no heavy load items running, just the TV and some lights, certainly nothing that would chug through nearly 6kwh in 15 minutes! I attach two screenshots from the Fox app that show the occurrence.

I had a couple of concerns about the tech who installed the new slave. Firstly, the existing battery was fully charged and he said there was no need to run it down to 50% (as I have read elsewhere). Secondly, he neglected to set the dip switch at P3 (from P2) to accommodate the fourth slave. Lord only knows why I checked this, probably because I never trust anybody to do a proper job!

My question is, could either of the above have been a factor in the malfunction, and should I be concerned that any parts of my system will have been permanently damaged?

Thanks in advance for any help or advice

Matt

[Will]

Good morning,

So on newer firmwares the dip switch is ignored but I would personally still set it correctly to avoid a future issue should be default behaviour change. So shutdown the master battery using the power button. adjust the dip by one and then power the battery master back on.

Concerning to hear your installer didn't follow the install manual by matching the soc to 50% prior to install. The 50% SoC during install of the additional slave while it has not hurt anything, it is important to do so that it aids balancing of the cells. The reason you're seeing large jumps in SoC over a short periods of use is down to him installing a half full battery into a fully charged system.
Balancing will now take somewhere between 2 to 3 weeks of daily cycling before the battery starts to behave normally again but it's really nothing to worry about or anything you can do.

[Giggermatt]

Thanks Will, that’s incredibly helpful, and good to know that it should only be a short term frustration.

Cheers - Matt