After months long diagnostics, replacing inverter (6000xp), investigating other members experiences I came to conclusion that the BMS of EG4 indoor wall mount battery has serious comms issues preventing the battery to be used in closed loop mode (inverter setting to battery type Lithium). I believe it is the time I rise it up so EG4 can pick it up and address in next firmware update and provide affected users with tools/gear to actually perform their BMS firmware updates on their batteries.
Here is the issue with BMS.
It appears that randomly Battery BMS loses the comms to the inverter resulting in the inverter acts like there is no battery connected to it. The instances are 1-2s only - basically not able to be captured by EG4 web monitoring (which samples the system every 4-5min only). it can happen few to several times a day.
The result is that inverter goes to by-pass mode and conveys grid power until it senses the battery is present. So if one has grid connected setup it is almost unnoticeable as the inverters transfer switch provides seamless power supply transition between battery/grid/battery.
For those folk who are in off-grid mode (no grid connected) it is obviously noticeable it results in power frequent 2-5s power losses with consequences potentially more severe (surge affected electronics, fridges, etc.). Basically I had to invest in multiple UPSs and whole house surge protection installed to prevent comms disruption and equipment damage (lost two subwoofers and AVR due to those power blips while off-grid)
To make the story short:
It doesn’t matter which inverter one is using. Once the wall mount battery comms is lost - bypass to grid, interrupted battery chagrin or short blackout for those off-grid
Related posts:
statements from:
@scottmr808, @BPorter , @frankorth
Supports my conclusion that EG4 wall mount battery can be reliably run ONLY in open loop mode (run as Lead Acid)
Here is the data from my system supporting my above statements.
I gave up more testing and run EG4 Wall-mount indoor battery in open loop mode (set up as as Lead Acid type).
It is inconvenient yet it works. A temporary solution until EG4 fixes the BMS firmware and provides tolls to rectify the flaw.
@EG4
ball is in your court.
Brgds
K
I have this happening not just to a client with 6000xp and Wall Battery, but also to a client with 6000xp and two server rack batteries. Fortunately its only these two clients, not the dozens I have running off grid with these solutions. Possible that it happens with the grid interactive clients I have installed also and they don't know!
Would really like to see this addressed. There has got to be some downside from permanently running lead acid mode as a workaround ..... besides the customer going 'WTF why does it say lead acid' and me having to explain the glitch ... ;(
As mentioned, there is zero data in the events log when this happens, its a silent momentary event that is intermittent enough to be a real PITA to catch and debug
@grayson
@dakota
@eric
Another bunch of supporting data attached - this is from my previous (RMA-returned May 2025) 6000xp with same Wall Mount EG4 battery.
there was only one instance the EG4 monitoring ap data sampling coincided with the power loss event - line 197 of attached spreadsheet - and the event was recorded (no battery seen bay inverter).
@EG4
Hope some knowledgeable EG4 folks can use that to fix the issue. SS tech were not able to - just issued RMA and I got new inverter with the same problem
Brgds
K
YES! I believe this (as is described) is what's happening to me now! Many repeated blackouts, restarts, and standby modes for no apparent reason. Two 12000xp's and two PowerPro Wall mount (1 indoor, 1 outdoor) batteries. I couldn't stand to be on the phone music for another 2 hours with no answer as I have been the past few days, so I just shut everything down to do more research and try again next week!
Also confirmation... I never had this problem with a 6000xp and 1 wall mount outdoor battery—glitches began when we installed the INDOOR battery in the parallel set-up!
i've copied this message from another thread on this subject. My equipment is, FlexBoss21 and indoor 280 AH Lithium Wall Mount Battery.
K
Well it's been about five weeks since I changed my Battery setting from Lithium to Lead Acid on 7/29.
My home owners insurance has always included a subscription to a device called "Ting". I keep the device pluged the in and it monitors lots of different electrical things, to prevent fires (that's why the insurance covers it).
While the "Blackouts" have not gone away they have been greatly reduced. Before I was getting one or two almost every day in July. Most of them were long enough that I needed to reset my WiFi modems. That was a pain.
Since 7/29 I've had three "Blackouts" and none of them required any WiFi resets or clock resets.
While this is better it's still not ideal.
I hope that EG4 figures this out as someday most of us are going to sell out homes and explaining this work around to a buyer would be embarrassing.
I'm going to past this thread, assuming I can figure iti out, to another thread I've been linked too.
Bill
Above is the snapshot of Event Log from my replaced 6000p indicating when the Wall Mount Battery BMS problems started. As mentioned before the 6000xp was RMA replaced in June 2025 and the problem persist. The returned inverter was bench tested by EG4 and found fully operational (as per SS tech support).
I am waiting on EG4/SS response to provide RS232/USB kit to check/upgrade that BMS firmware before I decide to attempt to switch back to Lithium battery type
Brgds
K
@krzysiek_kta
If you haven't head back from anyone, I can submit a parts request and get that firmware cable shipped out.
The next step would be to make sure the BMS (RS232) firmware is up to date.
Thank you for the response. Looking forward to receive RS232/usb kit to update the BMS firmware.
Brgds
K
Has anyone ran the battery in lead acid mode?
Pawnee,
Yes, both K and I (at least) have used this to try to make our solar systems work properly.
We have different inverters but K has done some exhaustive work using his installers teck people and I talked to four different people at EG4. We were both assured that running our batteries on lead acid isn't a big deal for them. When my battery was installed the default was to run it in lead acid mode for a month and switch it to lithium ion after a month. It was some sort of break in period.
We are hoping that when he gets the communication cable to check his batteries BMS that it is up to date.
@pawnee yes, i am now running the 2 wall mount all weather batteries in lead acid mode. The 6000XP was not charging up to the required voltage and i was advised to do.
i still have other issues that are surfacing… my first inverter died after only a few months and i had to replace it. Now i have an warning 18 about frequency out of range and telling me that the generator has been on for a day… i am totally off grid and have no generator.
it is very frustrating.
the following thread relates to run the battery in Open Loop (Lead Acid) mode.
My charge setting are set up accordingly - Its not ideal, but works