Before I get into my experience of the 18K PV inverter, I owe this community a debt of gratitude. I started this DIY solar journey back in Jan of 2022. At the time, I didn’t even know what an ampere hour, KWh or BMS was. It was because of this community and some persons on YT like Will, Andy, David Poz and others, that I came from a point of knowing nothing about solar to now having completed my offgrid DIY solar system including building my own 30KWh battery (will be expanding to 60KWh in a few weeks). This community is awesome.
I also have to thank the Signature Solar support folks. They have been nothing but great in assisting with configuration changes of this unit until I learnt the unit and got comfortable that I can make the config changes myself.
Just a little background about my system. I’m using an EG4 18K PV inverter with 3 strings. East, south and west. Each string is 5KW of panels for a total of 15KW. I’m planning to add another 5KW of panels south side in a few months. I’m using a single DIY LFP battery 30KWh configured as a 2P configuration CATL 302Ah cells and a Daly Smart 500A BMS (I know, I know…Daly right? ). I’m using my 18K PV in self consumption mode. I’m not selling back to the grid and I’m not using the smart load or generator features either.
Here’s a basic layout of my system.
So I’ve done around 1.4MWh of PV through the 18K PV inverter. Spoiler alert…I’m impressed with this unit. They are however a few small things I don’t like and I’ll get into that shortly.
My first 1000KWh or so of PV, the inverter was running without batteries. So essentially, I was running my entire home (with the exception of charging the car) entirely on solar during the day, then the inverter would pull power from the grid at night. I ran the inverter this way for about a month. It worked flawlessly. They were some minor changes that SS made because my grid power voltage dropped a little below the threshold that was in the inverter’s software by default as well as the grid frequency which would cause the inverter shut down, which is what the software was configured to do, so the unit functioned the way it was supposed to. After making the configuration changes to better suit my grid quality of power, it was smooth sailing from there. Truth be told, if this didn’t happen, I wouldn’t have known that my grid power had fluctuated the way it did.
I then built my single 30KWH LFP battery. 32x CATL 302Ah cells in a 2P16S configuration using a Daly Smart 500A BMS. I’m currently using that battery with the 18K PV as lead acid as there’s no communication and the inverter again works flawlessly. I have the communication board from Daly and will be attempting communication between the BMS and the 18K PV soon. I’m also keeping my eye on the new JK 200A BMS which also offers communication. From what I can tell, it seems as though it does an easier job with communicating but we’ll see. I plan to do a part 2 to this write-up specifically focusing on the 18K PV with DIY batteries. I know server rack batteries are the rage right now and they seem to work great. But for me, I already had my cells before I got the 18K PV and I love tinkering with stuff so I think I’ll be in the battery DIY camp for a bit.
So, here’s the things I like and dislike about my 18K PV experience.
Things I like:
Quality Inverter- The inverter just feels and looks well built. When you open it, there’s a lot of space in the wiring compartment. The components look well made. Quality of breakers, bus bars, connections, everything looks solid and is well placed.
General Support- I know many folks have reported negative stories about SS’ support. Before I got the 18K PV inverter, I purchased 2x 6500EX. I actually sold them and bought the 18K PV. I never used the 6500EX inverters, but I had a lot of questions about them when they arrived. Each time I reached out to SS, I got a reply within a day or 2 with proper responses/explanations to my questions. The same thing occurred with the 18K PV in terms of support. At no time did I have to wait for several days for a response, so my experience overall has been positive.
Remote Support- Once the 18K PV is configured with wifi access, SS can access the inverter remotely. This helps tremendously with troubleshooting and assisting customers with configuring the device.
Tons of Options- Tons of options are available in terms of how you can configure this device. I’m using self-consumption mode and not selling back to the grid. At first glance, all of the options looked a bit intimidating but once you get the hang of what options don't apply to you, it becomes easier to deal with.
Mobile App- The mobile app is brilliant....mostly. I love that I can stay from the office, pick up my phone and see what my system is doing. The app also gives me tons of options that I can change as well. The inverter has the ability through its wifi dongle to provide remote monitoring without the need for additional devices like the raspberry. I do like this integrated approach and keeping things simple.
Wiring Experience- I find the wiring experience overall to be easier than with the 6500EX inverters.
The Hybrid Life- I love the fact that this inverter can blend power sources to power my loads. I like that if solar isn’t enough, it can pull the difference from the grid and not a all-or-nothing approach. Even though I am now offgrid, I’m still keeping the grid connected in the event that I have to bring down the system for maintenance. When I upgrade from the 30 to the 60Wh of batteries, I’ll then be charging the EV directly from solar instead of the grid and the grid will literally be there just waiting in the event that I run out of battery power or PV or have to take the system offline for maintenance.
Things that I’d like to see improved:
Speed to refresh data on app- Both the web interface and mobile app seems to take a few minutes before it shows up to date information such as power draw from loads, PV created etc. I never timed it but seems to take a few minutes. Being a computer systems person myself, I get that issues can arise in generating real time updates with something like this but still, I think a few minutes is a bit too long. Would like to see something that is perhaps updated every 10 to 30 seconds. I think though that SS may be looking at this. The actual screen of the inverter itself seems to be closer to real time info.
Now that I’m at this point in this review, I just realized I should’ve titled this section ‘Thing’ that I’d like to see improved instead of ‘Things’. To be honest, I really can’t think of anything else that bugs me about this inverter. And believe me, I looked. It took me a few months before writing this review. I’ve put this unit through the paces for my use case and have been looking relentlessly for flaws and as of now, outside of the slow update of power stats from the app, I can't say that I found any flaws.
Summary
Would I buy this unit again? Absolutely. I think if you want a beefy inverter capable of producing lots of power, good set of bells and whistles, easy setup and you have the budget, then this one is for you. If you’re more budget sensitive and just want the basics of an offgrid set, I think the 6500EX inverters are still a very good buy.
When the 18K PV was first announced, I must admit I had some issues with it based on what I saw on paper. But having now had the product installed and using it for the past few months, I am very happy. It works very well and I finally have the peace of mind of not having to worry about grid blackouts.
My next review will be focused on using the 18K PV inverter with DIY batteries and communication. I do have the inverter setup currently without communication and that was only for the purpose of testing to see how it performs. I am working towards getting my battery communication going.
I also have to thank the Signature Solar support folks. They have been nothing but great in assisting with configuration changes of this unit until I learnt the unit and got comfortable that I can make the config changes myself.
Just a little background about my system. I’m using an EG4 18K PV inverter with 3 strings. East, south and west. Each string is 5KW of panels for a total of 15KW. I’m planning to add another 5KW of panels south side in a few months. I’m using a single DIY LFP battery 30KWh configured as a 2P configuration CATL 302Ah cells and a Daly Smart 500A BMS (I know, I know…Daly right? ). I’m using my 18K PV in self consumption mode. I’m not selling back to the grid and I’m not using the smart load or generator features either.
Here’s a basic layout of my system.
So I’ve done around 1.4MWh of PV through the 18K PV inverter. Spoiler alert…I’m impressed with this unit. They are however a few small things I don’t like and I’ll get into that shortly.
My first 1000KWh or so of PV, the inverter was running without batteries. So essentially, I was running my entire home (with the exception of charging the car) entirely on solar during the day, then the inverter would pull power from the grid at night. I ran the inverter this way for about a month. It worked flawlessly. They were some minor changes that SS made because my grid power voltage dropped a little below the threshold that was in the inverter’s software by default as well as the grid frequency which would cause the inverter shut down, which is what the software was configured to do, so the unit functioned the way it was supposed to. After making the configuration changes to better suit my grid quality of power, it was smooth sailing from there. Truth be told, if this didn’t happen, I wouldn’t have known that my grid power had fluctuated the way it did.
I then built my single 30KWH LFP battery. 32x CATL 302Ah cells in a 2P16S configuration using a Daly Smart 500A BMS. I’m currently using that battery with the 18K PV as lead acid as there’s no communication and the inverter again works flawlessly. I have the communication board from Daly and will be attempting communication between the BMS and the 18K PV soon. I’m also keeping my eye on the new JK 200A BMS which also offers communication. From what I can tell, it seems as though it does an easier job with communicating but we’ll see. I plan to do a part 2 to this write-up specifically focusing on the 18K PV with DIY batteries. I know server rack batteries are the rage right now and they seem to work great. But for me, I already had my cells before I got the 18K PV and I love tinkering with stuff so I think I’ll be in the battery DIY camp for a bit.
So, here’s the things I like and dislike about my 18K PV experience.
Things I like:
Quality Inverter- The inverter just feels and looks well built. When you open it, there’s a lot of space in the wiring compartment. The components look well made. Quality of breakers, bus bars, connections, everything looks solid and is well placed.
General Support- I know many folks have reported negative stories about SS’ support. Before I got the 18K PV inverter, I purchased 2x 6500EX. I actually sold them and bought the 18K PV. I never used the 6500EX inverters, but I had a lot of questions about them when they arrived. Each time I reached out to SS, I got a reply within a day or 2 with proper responses/explanations to my questions. The same thing occurred with the 18K PV in terms of support. At no time did I have to wait for several days for a response, so my experience overall has been positive.
Remote Support- Once the 18K PV is configured with wifi access, SS can access the inverter remotely. This helps tremendously with troubleshooting and assisting customers with configuring the device.
Tons of Options- Tons of options are available in terms of how you can configure this device. I’m using self-consumption mode and not selling back to the grid. At first glance, all of the options looked a bit intimidating but once you get the hang of what options don't apply to you, it becomes easier to deal with.
Mobile App- The mobile app is brilliant....mostly. I love that I can stay from the office, pick up my phone and see what my system is doing. The app also gives me tons of options that I can change as well. The inverter has the ability through its wifi dongle to provide remote monitoring without the need for additional devices like the raspberry. I do like this integrated approach and keeping things simple.
Wiring Experience- I find the wiring experience overall to be easier than with the 6500EX inverters.
The Hybrid Life- I love the fact that this inverter can blend power sources to power my loads. I like that if solar isn’t enough, it can pull the difference from the grid and not a all-or-nothing approach. Even though I am now offgrid, I’m still keeping the grid connected in the event that I have to bring down the system for maintenance. When I upgrade from the 30 to the 60Wh of batteries, I’ll then be charging the EV directly from solar instead of the grid and the grid will literally be there just waiting in the event that I run out of battery power or PV or have to take the system offline for maintenance.
Things that I’d like to see improved:
Speed to refresh data on app- Both the web interface and mobile app seems to take a few minutes before it shows up to date information such as power draw from loads, PV created etc. I never timed it but seems to take a few minutes. Being a computer systems person myself, I get that issues can arise in generating real time updates with something like this but still, I think a few minutes is a bit too long. Would like to see something that is perhaps updated every 10 to 30 seconds. I think though that SS may be looking at this. The actual screen of the inverter itself seems to be closer to real time info.
Now that I’m at this point in this review, I just realized I should’ve titled this section ‘Thing’ that I’d like to see improved instead of ‘Things’. To be honest, I really can’t think of anything else that bugs me about this inverter. And believe me, I looked. It took me a few months before writing this review. I’ve put this unit through the paces for my use case and have been looking relentlessly for flaws and as of now, outside of the slow update of power stats from the app, I can't say that I found any flaws.
Summary
Would I buy this unit again? Absolutely. I think if you want a beefy inverter capable of producing lots of power, good set of bells and whistles, easy setup and you have the budget, then this one is for you. If you’re more budget sensitive and just want the basics of an offgrid set, I think the 6500EX inverters are still a very good buy.
When the 18K PV was first announced, I must admit I had some issues with it based on what I saw on paper. But having now had the product installed and using it for the past few months, I am very happy. It works very well and I finally have the peace of mind of not having to worry about grid blackouts.
My next review will be focused on using the 18K PV inverter with DIY batteries and communication. I do have the inverter setup currently without communication and that was only for the purpose of testing to see how it performs. I am working towards getting my battery communication going.
I can't wait for signature solar to get the UL stickers so it ships out. can you guys point me to the quick disconnect I can use for 4/0 cables to attach to one of the new batteries? thanks
