EG4 Electronics

It has worked very well to run our entire house in two years l've had it running my home. I initially had some trouble with it limiting the solar voltage it would accept, but we fixed it after a couple of firmware updates (these were early adopter issues that they have since resolved). It also took me some time to get the settings right, but Signature Solar did a great job supporting me. I've liked it and I would do it again given the situation I had at the time. Next inverter will be more powerful because my home's power needs have increased. Overall it has been more than worth it.

chickabees Verified owner · Oct 23, 2026

The Flexboss18 has been powering my 2000 sq. ft. house constantly for 10 months as of October 2026. I have 13kW of panels connected to it and 32kWh of RUiXU Lithi-2 batteries. It is grid connected through a GridBoss. Every setup is unique and YMMV. The hardware has been very reliable. The software is another story. It's difficult to tell with the EG4 web/app interface how the system (including a GridBoss) will react with a given configuration and situation. It can also be very slow to get updated readings (minutes). The mfg. documentation is lacking in explaining how the different combinations of settings will work together. It requires a lot of trial and error. Once you figure out the behavior of the system with a given set of settings, the hardware will hold the settings and behavior reliably 99% of the time. In their web software, there are features that tech support admitted were not ready for primetime. Specifically, "Weather Optimize" is one such feature. There is a lot of ambition behind the features exposed for the hardware. It would be amazing if it was easy to use and understand and if it all worked as expected. In my opinion, QA for their software is lacking. I've used tech support one time. They were quick to respond and helpful in examining the issue (why is my system using grid power when it shouldn't be?), but ultimately could not say why it was happening and "fixed" it be clearing all settings and reapplying. There is no way to easily do that same operation in their software. You'd have to enter all settings in again manually after clearing them. Some of the software hiccups may not apply to you if you don't have a GridBoss, as much of the complexity lives in the interaction between it, the Flexboss18, the batteries, and the grid. The wifi dongles are a weak point. Range is not great and there is no option for an external antenna. Seems like an oversight given the amount of metal the dongle is near in its location on the side of the inverter. The dongles also do not allow you to disable the wide-open bluetooth. Anyone could pull up next to your house, connect to bluetooth, and control your system. The monitoring/config website does not have MFA as of 10/2026. This is incredibly concerning given the ability for it to reach into your house and control your power. I do not recommend this EG4 inverter and ecosystem unless you are an expert user willing to spend a lot of time to understand and troubleshoot the setup. You may also want to consider the weak hardware and software security. The system can be made to be secure without losing a lot of functionality, but you will need additional hardware and you'll have to effectively build your own software automation.

starman Verified owner · Oct 21, 2026

So far so good but the app is just awful. Running my loads, no issue. I had to rewire my panel to get everything working. Now I'm off-grid and it works great.

Anonymous · Oct 18, 2026

So, the only thing that went wrong was one of my Degson terminals on the positive bus bar cracked (the plastic cracked). I was a little surprised to have to RMA a battery I'd had less than a week, but Signature Solar didn't hesitate to replace it. I offered to take it apart with them on the phone and repair/replace the damaged terminal, if they'd send me replacement parts, but they said, "nope, we're sending you a new battery." So, if you get one, please be careful, especially when/if you're removing one of those Degson connectors. They don't come off as easy as you'd think. And, if you find yourself fighting with it, stop. You're not doing it right. Call someone and ask for help. Otherwise, you'll find yourself removing the inverter, the conduit box AND the battery, and starting all over again. Once I got past that fiasco, it's been flawless. Both of them. I'll probably end up getting four more of the exact same. I mean I've looked at every wall-mount and server-rack battery you can imagine. Dozens and dozens of them. And, I keep coming back to the EG4 314Ah Indoor wall-mount, because, "yeah, that battery is cool, but it doesn't have this (like mine does). And it doesn't have that either. Oh, and I forgot it doesn't have that as well." I mean, you get spoiled is all I'm saying. It's self-heating, 10-year warranty, fire suppression, active load balancing, 400A discharge (the set), 250A charge, the best cells you can find with extremely-high-build quality (outside the plastic Degson connectors), all the right UL certifications (the ones that actually matter), sleek design, etc. Yeah, it doesn't have a touchscreen, but who cares...? That's what Home Assistant, and Solar Assistant, and EG4 Connect/EG4 Monitor is for. It comes with a fancy bluetooth dongle you'll never use. But, what really matters are the cables. I mean, if you find a battery with better cables, show it to me. 95% of the batteries out there come with cheap/garbage cables you have to end up replacing. Not these... I don't like how expensive the parallel cables are, but honestly you can easily make your own from leftover cables (assuming you bought more than one battery) and some connectors you can easily purchase for $20, assuming you have a hydraulic crimper. The final point is that it's dense. It packs a lot of energy storage in a very small footprint. If you have wall space, this is what you want. If you only have vertical space, and extremely limited wall/floor space, then you should look into a closed-cabinet, server-rack pack of batteries.

royvanmiral Verified owner · Oct 16, 2026

In my opinion EG4 has tried to cut costs and make more money. Thus they have more problems. They caused me a lot of problems with high-voltage spikes.

jp1gt · Oct 15, 2026

So, when I commissioned this first 12000XPv2, I was expecting to be able to force it to fail over to the grid, but I couldn't. I turned on absolutely everything we had, across 6 structures. To the point where we were pulling in 14,000 watts of solar, and over 12,000 watts from the batteries (over 55amps per AC leg on output) and it held that for 10 minutes, when I finally said, "that's enough." I remember telling my wife on the other end of the line, who was turning all the appliances and lights on, "man, this thing is impressive." It's only failed over to the grid when we've hit our battery reserve of 20%. It's paired with two EG4 314Ah indoor wall-mount batteries, and it punches way above its weight class. I'm assuming part of that is the fact I used only the very best wire I could find, and oversized every wire in the entire circuit. Bottom line, I'm getting another one. I have absolutely zero desire to export to the grid, because the utilities are awful. The one downside is if you're using only one 12000XP to power your house or property, and you've got some distance in your feed lines (hundreds of feet), you will absolutely notice some light flickering at certain times of the day. Like when it's heavily charging the batteries with 150+ ams, and you've got an additional load on the circuit (say 8000 watts or more), voltages will drop, as happens in high-frequency inverters, and you'll see flickering at those moments. During normal operations, you shouldn't see it at all. But, a second (in parallel) 12000XP should permanently solve that. My only desired improvements are a 3rd (totally separate MPPT). I don't mind the 2 (in parallel) MPPTs = 4, but it desperately needs a 3rd independent MPPT. And, it needs a true 200Amp bypass, not like the fake 200A (really a 125A) bypass of the Watt Cycle 12000 Super. If it had those two improvements, and they could keep the cost down around where it is now ($1900), and it's still being built in Corinth, Texas, then it would remain king for quite some time to come. I know Watt Cycle did a decent job of copying it with the Super, but that's all it is: a copy.

royvanmiral Verified owner · Oct 14, 2026

I installed this system as a DIY project over the Christmas holidays in 2025, getting formal PTO from by PoCo in February 2026. This was a permitted and inspected install The total system is 25 kW of solar goodness, including 8 kW of AC couple on the GridBoss. It has been operating without a hitch for 9 months straight, mostly self-consumption. The installation was easy, with the FlexBoss mounted on the outside of the BossBox. Getting 3x300 pound batteries in the BossBox was the painful part, not the inverter. The firmware stabilized with FAAB-2727 and my only complaints are minor. First that the web and app monitor don't take into account AC Coupled solar fed into the GridBoss, so the reported total solar production says 15.2 MWh. My AC Coupled adds another 7.3 MWh, so while it shows in the flow on the monitor, the totals aren't totaled. The simple TLDR is it has just worked for 9 straight months without any issues.

chill633 Verified owner · Oct 13, 2026

Following a few minor teething problems when configuring the three inverters as a three-phase system, the system is now running flawlessly. Problems encountered when restarting the system have been resolved with new software.

oschubert · Oct 13, 2026

A few software glitches at the beginning; however, it has since been patched with firmware updates. Had one instance where the output got stuck in grid bypass mode after a heavy storm. EG4 support got me back up and running on solar in about an hour. I was quite surprised by the customer support. Has been very reliable over the last 2 years, day in and day out. I've put over 35 MWhs of solar through this unit so far.

richard Verified owner · Oct 13, 2026

Wow, I can't believe it has almost been 2 years since I got this inverter. Overall it is great, and I would recommend it to family, friends, or anyone else. I bought it at $2,500 and thought the price was good, but now it is for sale at $1,900 and it seems like it is going to stay at that price. Nothing in life is perfect, and there are small things to note about this inverter. Since there is a version 2 out, which only has some mild changes, some things may be worth knowing for either version. -Wifi Dongle: This might be updated/fixed now, but it still comes up online and I have had many hours trying to get mine working properly. The dongle really is the worst part. The app software is a bit rough around the edges too for setup, because the dongle it's self works fine when setup. It really seems to want a 2.4Ghz network. Also the dongle only sends updates every 10 seconds or so. This isn't a killer, because no sane person really should be watching it all day, but it would be nice if it was closer to 1 or 2 seconds. -Firmware Updates: The first firmware it was shipped with had some bugs in it. To be fair, it was a brand new product, and I knew I was early adopting. But the specs were everything I wanted and a price I liked at the time. The PV MPPT was not working properly in the morning, and I would have to disconnect and reconnect the PV(breaker or disconnect switch) each morning. They sent a beta update to me within days of me calling. The EG4 and Signature Solar customer service has always been great, even if some aren't as skilled at SS. The next public updates have been fine up to 0507, then 0709 came out with new features I wasn't ever expecting to see! But it messed up the charging and would not keep the batteries at my specified voltage after reaching it. The battery would then go down to resting voltage, so essentially, the battery cells would not properly be able to balance well. So I called, and SS could not revert, and they had me call EG4, and they did the process for me. It was fairly quick for me, after figuring things out with both companies(that it wasn't my fault). So there is a new firmware updated expected to be released in the near future(it has been many months of waiting though), and hopefully that fixes my issue. If not, I can just roll back to 0507 and everything works just fine. Note that I do run in Lead-Acid mode/Voltage, not SOC mode. This is to give my batteries the best chance of properly balancing, and I also didn't like when the batteries were controlling my inverter. Now it is more of a 2 step safety this way too. Install was as expected. It will only be easier or harder depending on each person's situation, but it requires 2 people to safely lift it into place, or another alternative method. It is heavy and big. UPS(uninterrupted power supply) works well, even if you are on grid power usage, or charging on too, if it drops out, you may get a tiny light flicker but nothing shuts down in the house, or annoying time clock fixes. Loads: In Florida, it "can" run a normal sized single family house, with limitations. 2 would be ideal in parallel. That said, I have reduced my water heater element to 2500watt, instead of 4500, put a soft start on my air conditioner(needed for voltage drop on startup), and I do try not to overload it. So when doing laundry I can draw 7KW from just that, then the A/C to 10,000 and regular loads of house run around 1KW-2KW. Which brings me right to the edge. So turning on a microwave at the wrong time can push it over to grid power. But it really isn't a big deal, just hurts the soul a little each time(haha). After a few minutes back in normal usage, it goes right back to battery/solar. A 2nd one would fix this, so it is not the unit's fault, just something to keep in mind for anyone looking to buy. Also SS says you can mix a V1 and V2 together, which is good for anyone in my situation, as I may end up doing that some day. I really don't have much to complain about this product, and these days where it seems disappointment is too often there, I thought to myself a few days ago, I am really happy with it overall and glad I got it. It still has 3 years of warranty, and I ideally want it to last 10+ years. Preferably longer, but I know inverters don't typically last forever. I guess one thing is the fans get a bit loud at higher current. When you start getting around 10KW or more for charge or discharge, they get pretty loud. Its not terrible, and they vary with the load. Way better than some other options out there. So I wouldn't keep this thing in an office or inside anywhere close by. Current Recommendation: Buy it, and enjoy it!

travis Verified owner · Oct 13, 2026

When this is your jumping in product into solar there are bound to be teething issues that said the 6000 XP is very capable. Hardware wise no complaints. On the software side the EG4 6000 XP paired with the powerpro batteries likes to hiccup and lose comms sometimes very often leading to wild and crazy faults. You will find like I did going OPEN LOOP will cure 99% of the issues. I had many issues with lost comms between inverter and batteries and SS pretended like this was the 1st time they had EVER heard of the issue. I found out later through the diysolarforum.com I was not alone and learned about OPEN LOOP that way. On the software side the web app can be a life saver or a curse depending on how you look at it. The EG4 mobile app is just terrible. I would not hesitate to purchase another one if I needed it. But I need bigger and I would suggest if this will just fit your needs go one size bigger.

ehnus Verified owner · Oct 5, 2026

The battery works like a champ. It likes to have comms issues between the 6000xp and its self. Causing the 6000xp to freak out. Once in OPEN loop flawless... Would but again if they were cheaper. There is no active monitor for these batteries and that is terrible EG4 should do better.

ehnus Verified owner · Oct 3, 2026