Technical Support Bulletins (TSB) - EG4 Community Forum

indoor Wall mount 280Ah will notcorrectly charge

cptmorgemaker — Mon, 30 Mar 2026 12:17:03 +0000

Morning, recently added my sixth battery to my system. It currently has two 314 indoor as one and two and four 280 indoor batteries. A grid boss a flexboss 18. And a flexboss 21. FlexBoss, 21 is The master and it is hooked to battery 6. Wear FlexBoss 18 is hooked to battery three. They share batteries. The newest battery which is id4 will not charge to the same voltage as my others. I've even changed my FlexBoss 18 to a master unwired the communication between the other batteries and the inverters and told it it only had the one battery and had it trying to charge up and it just still wouldn't. I've tried the SOC recal break and that seems to have not worked either. Any help would be great.

Master flexboss21 I'd is - 44700E0278

Slave flexboss18 id is - 52601N0070

How their ID is is deceiving because of how I had to string the communication being you must have three 14s as the primary one and two battery. I added them to an existing three battery system. As you know they just came out and not wanting to unwire and move my FlexBoss 21 to move that battery to become a primary was the reasoning of their positions. Also, if you go on to my network onto the system you will see for the batteries to of communicate correctly. I actually had to go down an ID it seems the 314s like to start it. Battery number zero. So my batteries are 0,1,2,3,4,5. That seems to be the only way that they wanted to communicate correctly. And all the wiring's correct with the custom-made network cables.

2576 2578

EG4 Wi-Fi + Ethernet Dongle does not work on Ethernet path

fkitzmann — Wed, 11 Feb 2026 01:12:08 +0000

I recently purchased a Wi-Fi + Ethernet Dongle. I'm currently having issues with it loosing the Wi-Fi connection (Distance issue). This is pretty much the reason that I had purchased this adapter in the first place as I wanted to remove my dependencies from Wi-Fi and range issues by having a direct Ethernet connection to my router.

Currently the adapter is connected to my network through both Ethernet and Wi-Fi. I am experiencing the following issues with this dongle.

Sometimes the Wi-Fi connections drops out. This would still be ok if the Ethernet path would take over, but it does not in my case.
There is no way to determine if the dongle is running under Wi-Fi or Ethernet. When I look at the EG4® WI-FI ETHERNET MONITORING

ADAPTER QUICK START GUIDE. It says the following -

How can the end-user determine the current communication mode of the dongle (Ethernet or Wi-Fi)?
• Check the IP LED flashing frequency. Ethernet mode: IP LED flashed slowly (once per second). Wi-Fi mode: IP LED flashes rapidly (three times per second).

My dongle does not show these flash rates with the IP LED. It's only solid on. As such, I can't be sure which path is being used.

Also, the two network LED's at the dongle's recessed Ethernet connection, I see, are not on or flashing. Don't know if this is supposed to

work to indicate if this connection is working properly and data is active.

I did run an experiment verify that the Ethernet path does not work. I did this by making sure that the Wi-Fi signal could not be received by

wrapping the dongle with some aluminum foil. I made sure that my both my Wi-Fi router and my phone could not receive the dongles signal.

I then looked at the EG4 monitoring app and saw that I had no inverter data reporting back, where prior to wrapping the dongle with

aluminum foil, I had proper data coming back. So it seams obvious that there is no dongle Ethernet communications happening. Is the dongle supposed to revert to the Ethernet path if the Wi-Fi is down?

3. I see that this dongle has version V1.1. Suspecting a newer version, I then tried to see if there was an update for it even though this is a new Dongle just received from Current Connected.

The EG4® Wi-Fi Dongle DONGLE FIRMWARE UPDATE guide says to first connect to the dongles Wi-Fi and to select Dongle connect.

FYI, My IOS phone App is at V1.6.6 so that should be good. Then to connect to the dongles Wi-Fi serial number. In my case it's DQ53BLANK.

Which it does and stays connected. Then to use Dongle Connect, Bluetooth Connection. I'm then supposed to see the dongles Serial Number.

This does not show up for me and nothing else shows up, i.e. page is blank so I can't select anything. I then looked at the Bluetooth signal

area in my phone thinking that maybe it's a Bluetooth signal I should be using. None were found. So instead I went back to the app and

selected -

Dongle Connect - Wi_Fi Connect.

This method shows a button for V1.1 - Update firmware. Pressing that pulls up a firmware button labeled as - V1.1 - Update firmware.

Pressing that button then gives me the message of - Upgrade is successful. Please wait for another 2 minuets for the dongle to restart.

I then see the dongles 3 LEDs flashing and the it resets and re-establishes the Wi-Fi connection. I can also view the dongles connection

perimeters which all appear correct, but again no indication of which type of connection is is (Wi-Fi or Ethernet).

3. In any case, How can I get the Ethernet path to work?

a. Is V1.1 the latest version for dongle DQ53BLANK that I should be running? If not, where can I find the latest and how can I load it?

Can it be updated remotely?

Note that the web app also confirms this same version - WIIL xxxx V1.1 12/13/25 Connected

b. Would a newer version even fix the problem?

One other question. Does this dongle support Bluetooth? The reason I ask is that the DONGLE FIRMWARE UPDATE guide may be incorrect by stating to use Bluetooth.

Field Impact Notice- 48V Batteries

EG4 Eric — Wed, 14 Jan 2026 14:52:43 +0000

Summary

EG4 48V batteries that have been sitting idle connected to an EG4 inverter will have a small parasitic draw that is too low powered to be registered as power leaving the BMS. Over time this parasitic draw can drain the battery of stored energy while in an idle state, without the ESS recognizing the change to the SOC of the system.

Customer Impact

Affected customers may experience a rapid drop in battery SOC when turning on loads that require a greater draw from the battery. In some instances, this rapid drop can push the SOC under the shutdown percentage, leading to complete system shutdown and loss of power.

Resolution

The latest 48V battery Firmware from EG4 has been designed to perform a periodic voltage check of the internal battery cells to update system SOC. This voltage update will trigger an SOC decline and subsequent recharging before bulk SOC decays to a shutdown level. Affected customers should update to the latest FW as listed below:

314Ah Indoor: Z03T17
280Ah Indoor and Outdoor: S02T25
Lifepower4 V2: S02T34
LL-S 48V: S02T34

Field Impact Notice – 314Ah WallMount Charge Rate Suppression

EG4 Eric — Thu, 08 Jan 2026 16:47:35 +0000

Field Impact Notice – 314Ah WallMount Charge Rate Suppression

Summary
The firmware shipped on the initial batch of EG4 314Ah Indoor WallMount batteries (FW Version Z03T13) features a bug in which the charge rate of the battery is reduced to 15A (~750W) at temperatures above 65 °F.

Customer Impact
Batteries with FW Version Z03T13 active will experience a significant reduction in allowable charge rate, impacting the system’s ability to reliably recharge the batteries in a reasonable amount of time independent of the power availability on site. Depending on the system configuration, excess solar will be sold to the utility or curtailed to zero.

Resolution
A new firmware (FW Version Z03T17) has been made available which resolves this issue and allows the full charge rate of the battery in line with the temperature ranges indicated on the specification sheet for the battery.

This new firmware can be found on EG4Electronics.com under the 314Ah Indoor WallMount product page: EG4 WallMount 314Ah Indoor Battery - EG4 Electronics.

314Ah WallMounts deployed with an EG4 hybrid inverter (kPV or FlexBOSS) and with an internet connection can be updated over-the-air (OTA) by your installer. Batteries deployed with an off-grid (XP) inverter or without an internet connection will require an RS485 adapter (EG4 USB Read/Write Cable - Signature Solar) and a Windows computer. The write up on how to update using an RS485 adapter can be found in the .zip file containing the most up to date firmware.

Please call EG4 Support at 903-609-1988 for additional support with your system.

Field Impact Notice- DC|DC Defects

EG4 Eric — Thu, 08 Jan 2026 16:27:14 +0000

Summary
A manufacturing process gap from one of EG4’s tier 1 semi-conductor manufacturers was discovered in July of 2025 on the DC-DC boards used in EG4’s line of Hybrid inverters. Due to the gap involving a manual process, only a fraction of units manufactured during the affected period were impacted.

After discovering the process error, EG4 quarantined, re-tested, reworked and age-tested all potentially affected units in inventory, though some units were released into the field prior to intervention. Due to the time required to retest and rework impact units, the inventory position of FlexBOSS units became backordered, delaying RMA fulfillment. This inventory impact has since been resolved.

To date, the total RMA rate on sold FlexBOSS units from a DC-DC failure is 1.17%, and we do not expect this rate to go up any further.

Customer Impact
Upon a failure of the DC-DC board, the inverter will throw a W027: Battery open fault that does not recover on its own. While in this failed state, the inverter will still allow power to pass through (grid to load) and will allow PV production to continue, however will not be able to charge or discharge the batteries.

Customers who have experienced a DC-DC board failure due to this manufacturing defect (see verification process below) will receive an advanced RMA of their affected inverter.

NOTE: Issues unrelated to the DC-DC board manufacturing defect can lead to a W027: Battery Open fault. Please reach out to EG4 to pursue additional troubleshooting.

Resolution
To confirm a DC-DC failure, the following steps can be taken –

Use a voltmeter to test voltage at the battery terminals and voltage at the inverter's battery input terminals. If voltage of battery is between 48-56v and above the SOC/Volt cut-off, check to see that vBus2, located on the EG4 monitoring site under the Data - Chart tab, is 6 times the voltage present on the battery terminals.

For example, if voltage at battery terminals is measured at 52V, vBus2 should read ~306V. A reading less than 100V indicates a DCDC failure.

Upon confirmation of a DC-DC failure contact EG4 support at support@eg4electronics.com or call at 903-609-1988 for a Return Material Authorization (RMA). To expedite the process, please have your Inverter Serial Number available.

While awaiting a replacement unit, grid tied units allowed to export excess PV can continue to operate in PV only mode. To program the system to PV only the following steps should be taken –

Change the setting “Battery Type” to “No Battery” and the setting “No Batteries” should be set to “Enabled”

Mini Split Return

EG4 Eric — Wed, 12 Nov 2025 21:41:18 +0000

I'm not sure if everyone can view this video, but Tad Fuller explains that when returning an outdoor unit for an RMA, there’s no need to remove the refrigerant or perform any other steps on the unit. Since the mini split uses quick connects, those connectors prevent any air or moisture from entering the system. Once you receive the replacement unit, you can simply connect the quick connects and cables, and it’ll be ready to go.

https://www.facebook.com/share/v/1G9xx6ZsQM/

Random connection to Grid showing on display

sylinx — Wed, 05 Nov 2025 15:42:56 +0000

Hi. I have 2 x 18kPV in a primary/subordinate arrangement. The display randomly shows a connection to the Grid at times although the Grid volts and frequency is displayed. Being Grid tied it was expected to be connected ALL the time with a small amount of power being sent to the Grid (Zero export).

1932

Can you identify under what conditions the grid would be disconnected.

EG4 Gridboss Dongle Wifi Not Working

drewc — Fri, 31 Oct 2025 03:09:02 +0000

I have a similar situation to this guy:

https://forum.eg4electronics.com/community/tsb/eg4-dongle-ver-djxxxxxxxx/

Where EG4 had to ship him a new dongle. I'm guessing I have the same issue.

I just installed a Gridboss, and as part of the final steps, connected the Wifi Dongle to the external port for the dongle. When I do this, the Green WiFi LED flashes maybe twice a second, and no access point is broadcast. I look for a wifi network created by the dongle, but nothing ever shows up. The WiFi LED continually blinks. The manual for the gridboss indicated that the first thing I should do with the dongle is add its serial number and PIN to my existing station, which I have done. This does not appear to have done anything, and I wouldn't expect it to, as there is no way for me to get this thing connected to my home wifi. My serial number is DJXXXXXXXXX format (the number of x's might be off). Ideas/thoughts? EG4 support, are you out there?

I should mention, I have a functioning 18kPV with no wifi issues there at this site address. So I don't believe it's that, and I'm not even at the point where I can give it the local wifi anyway, as the gridboss is not properly broadcasting a wifi network for me to connect to in the first place.

500 Error When Registering

ray — Sun, 26 Oct 2025 22:06:25 +0000

I have two EG4 12000XP that I finally got hooked up this weekend. Problem is that 1) They don't charge from the PV. I get voltage but it never charges. I wanted to register the product to maybe be able to change things in the cloud but I get this error whenever I try to register. I'm not sure what to do here? I can change some of the settings on the inverter itself and was able to get the dongle connected to wifi but am stuck because the registration page is broken.

I'm not sure why the PV is not charging the batteries. I currently have only tried to get one online before I turn on the other one. I also get errors when filling out support ticket.

I see no error codes at all on my inverter, I have set the batteries to 0:Standard. Although the manual says this is 0:EG4 (incorrect). I also set them to Lux (6) that seems to actually work better as it correctly picks up the 6 EG4 Rack Batteries.

I have everything set up but don't understand why it will not charge the batteries. It reads 72 volts, but will only ever go into BatOffGrid mode.

But, first I guess I need to figure out why I can't register my account.

TTP Status 500 – Internal Server Error

Type Exception Report

Message Request processing failed; nested exception is java.lang.NullPointerException: Cannot invoke "com.w.server.core.bean.view.user.User.getUserId()" because "defaultCustomerCodeUser" is null

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException: Cannot invoke "com.w.server.core.bean.view.user.User.getUserId()" because "defaultCustomerCodeUser" is null

org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:982)

org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)

javax.servlet.http.HttpServlet.service(HttpServlet.java:515)

org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)

javax.servlet.http.HttpServlet.service(HttpServlet.java:583)

org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)

com.w.server.view.decryption.DecryptionFilter.doFilter(DecryptionFilter.java:129)

org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)

org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)

org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

Root Cause

java.lang.NullPointerException: Cannot invoke "com.w.server.core.bean.view.user.User.getUserId()" because "defaultCustomerCodeUser" is null

com.w.server.service.user.InstallerRecordService.doReportInstall(InstallerRecordService.java:283)

com.w.server.service.user.InstallerRecordService$$FastClassBySpringCGLIB$$8299745f.invoke()

org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)

org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:737)

org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)

org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)

org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:283)

org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)

org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)

org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:672)

com.w.server.service.user.InstallerRecordService$$EnhancerBySpringCGLIB$$76765ca1.doReportInstall()

com.w.server.service.device.inverter.InverterService.changeInverterPlant(InverterService.java:1362)

com.w.server.service.device.inverter.InverterService$$FastClassBySpringCGLIB$$787d9dff.invoke()