Luxpower 6000xp - Tries to switch to grid when batteries full

[Ambrotos]

I'm having a strange problem with my SNA-US 6000 (aka 6000xp) inverter. I'm wondering if anyone's seen this before, or has any suggestions.

The behaviour is that once the PV has charged the batteries to full, the inverter keeps trying to flip operating mode from Solar/Battery to Grid mode. It'll do this sporadically, but frequently. By that, I mean it doesn't do it regularly on a timed schedule (e.g. every 30 seconds). But it does do it often, anywhere between 15 seconds to 5 minutes. The inverter is completely off-grid, so it immediately flips back to Solar/Battery mode. This flip/flop causes a brief power outage. I have a network UPS connected to the inverter's load circuit, so I know when this is happening because I can hear my UPS buzzer go off in response to the power interruption.

This only seems to happen when the batteries are fully charged, and the load is less than PV potential. For example, let's say that up until the batteries were full I was drawing ~2500w from PV. Once charging is no longer required, PVin drops to something close to my base load (~300watts), and this mode flipping behaviour starts happening. If I were to plug in my EV charger and draw an additional 2500w (combined ~2800w, more than PV potential) the inverter would no longer attempt to flip back and forth between solar/battery and grid modes.

I'm referring to the modes as "Solar/Battery" and "Grid" because those are the two modes Solar Assistant displays. The inverter itself doesn't really display a "mode", and you have to just infer what it's doing based on the icons and arrows on the LCD. The flip seems to happen so fast that the LCD doesn't display anything other than what looks like what the manual calls "PV+BAT Off-Grid". The fact that Solar Assistant briefly shows a different mode means that some modbus register is telling it otherwise though...

Some relevant notes:

1. I'm running the latest firmware on my inverter (1A1011)
2. I'm running in open loop mode with voltage based charging. Absorb is set to 56.4v and float is set to 54v. I don't believe this is used by the inverter, but I've got the equalization voltage also set to 56.4v, and the interval set to 0 (which should disable equalization).
3. My batteries are a pair of EG4 LLv2 48v 100AH. They're connected to Solar Assistant via RS485 for monitoring, but as I said I'm running in open loop mode so not connected to the inverter's BMS port.
4. Since the inverter isn't connected to the grid, AC charging is disabled completely. Timeslots1/2/3 are all set to 0:00 - 0:00, grid-first is never, etc.
5. Smart load is disabled, export to grid is disabled, AC coupling is disabled

Sorry this post turned out to be a long one... I'd really appreciate any guidance or suggestions anyone may have.

-A

 

[rogerheflin]

Search eg4-6000xp on this site, I think I saw some of them having similar issues when the battery fully charged.

Verify that one or more of the BMSes is not shutting off charging. I though I also saw someone reference that with some BMSes in a master/slave setup if any one of the BMSes went into protection mode all may go into protection mode, and each time this happened it should cause a power blip.

 

[Ambrotos]

I'll definitely keep doing more digging through the forum for both Luxpower and EG4 posts.

I'm aware of an issue from last year where 6000xp inverters (either EG4 or Luxpower OEM) would exceed the configured absorption voltage under certain circumstances, which could trip a BMS's overvoltage protection. There's a thread about it here. But that particular issue was fixed for both brands in the firmware released back in August. In Luxpower-land, it was version 190D0E. That version's changelog specifically mentions "Optimize the BUS voltage high issue when the battery is fully charged". I'm sort of assuming that any references to full batteries triggering over voltage protection prior to August 2024 are probably related to that issue.

The EG4-LLv2's over voltage protection is set at 60v, and I haven't measured anything close to that. But point noted. I'll keep an eye on both BMSs to make sure they remain happy.

Cheers,

-A

 

[Ambrotos]

Just wanted to reply to this thread with some closure, for anyone in the future that sees this same thing.

I wound up engaging Luxpower support to look into this behaviour. After some investigation, the conclusion was that there was some error in the voltage calibration. I don't have much in the way of technical details, but at the end of the day they were able to remotely resolve the issue without requiring a firmware update. I've had several sunny days with full batteries since, and the issue does definitely appear to be resolved.

-A

 

[TerRob]

hello eg4 techs...I have the same situation with my 6000xp that Amr
brotos described. Would appreciate it if a eg4 tech could look at my machine to see if the fix applied to his machine might fix mine also...thanks

 

[EG4TechSolutionsTeam]

hello eg4 techs...I have the same situation with my 6000xp that Amr
brotos described. Would appreciate it if a eg4 tech could look at my machine to see if the fix applied to his machine might fix mine also...thanks

Can you please provide your inverter's serial number or station name and a brief description what exactly is happening?

 

[TerRob]

Can you please provide your inverter's serial number or station name and a brief description what exactly is happening?

Can you please provide your inverter's serial number or station name and a brief description what exactly is happening?

sure and thanks...home6000xp
when batteries are full and pv ramps down I get esp overloads even when loads are small. I never get overloads if I just run off batteries only or when batteries are only partially filled. Thanks for taking a look for me. If you need serial # let me know how to dm to you.

 

[EG4TechSolutionsTeam]

sure and thanks...home6000xp
when batteries are full and pv ramps down I get esp overloads even when loads are small. I never get overloads if I just run off batteries only or when batteries are only partially filled. Thanks for taking a look for me. If you need serial # let me know how to dm to you.

Thank you.
Which batteries are you using and how many?

 

[theonlydave]

Thank you.
Which batteries are you using and how many?

Hi same issue here for one of my customers. He has 3 6000XP's (providing three-phase power) with 2 EG4 14.3kWh wall mount batteries (indoor). Only when the batteries are full does the system throw EPS overload faults which is definitely not actually going on as the watts are well under the 18K power threshold or even the 6K per phase.

I'm currently in the process of upgrading the firmware on all the units to ccaa-191011.

Inverter communication protocol is set to 0 EG4 - and the same for the batteries. Any tips to help avoid this would be most welcomed.

Thanks

 

[TerRob]

Thank you.
Which batteries are you using and how many?

Eg4

Thank you.
Which batteries are you using and how many?

Lifepower4 v1...quantity 4