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MPP Solar LV2424 kicks butt!!!

erik.calco

Solar Badger
Joined
Nov 3, 2019
Messages
1,170
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USA
NOTE: Using this thread to track progress on tweaking LV2424 settings so that hopefully, in the future, someone with an LV2424 or similar MPP Solar inverter can benefit from it.
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I'll say, when I bought it, I had high hopes I could optimize for my requirements. But, wasn't sure. I have to say, I'm extremely happy with it.

I am configured off grid with manual transfer switches for 10 AC circuits. The LV2424 uses AC in. My requirements are:

- Utilize 100% of PV
- Keep batteries in relatively high SoC so I have plenty of juice when utility is down
- Have most critical loads continue to be on when grid is down, with ability to direct power to various other loads on an as needed basis
- No AC charging of batteries unless I have to catch up after grid being down.

Focusing on just the first two since the 3rd one is handled via a Relion transfer switch, the LV2424 has met my highest hopes!

The key is to always apply a critical load that is more than what PV can produce at any given time. While alone, this isn't 100% needed. As long as this is true, you will always use 100% of your PV. This is also true if your battery needs charging. But, the condition I try to avoid is having a full battery and load that is not enough to use current production.

To be sure, I only have 2 of my 6 panels online so far, and in a very inefficient setup. But, that is enough to monitor and tweak how the LV2424 behaves.

What makes this successful is the LV2424 seems to be "trickle" charging my batteries when not full even though the load is higher than production. That's what I hoped it would do. You can see that here:

1586028814714.png

Last night my battery voltage went to 25.4V. I consider 26.5V to be full based on how it behaves and has responded to this "trickle" charging. The inverter reading of 74% is wrong, so I just ignore that. Not sure if a full cycle would fix that, or if it will never correctly know the SoC.

It is also worth noting that when I did AC charging with 30A limit, if you happen to be watching it, it will hit a point where over about 10-15 minutes charging current will drop from 30A to 0A, which is what you expect when a battery is full. I suspect it then goes into float mode. If I had my way, I'd disable float as LiFePO4 doesn't need it. But, since I rarely use AC charging now, this isn't an issue. Just something to be aware of if you use AC charging a lot.

As for my critical load that is always on the inverter so stays on when grid goes down, it includes my refridgerator, a part of my living room with lights, outlets and charging for devices, and my servers, so my internet stays up among other things.

Here are my settings:

1586029235600.png

Charging source priority is Solar only. If I want to enable AC charging to catch up after the grid has been down, I can change that until they are full, then change it back to Solar only.

Solar power priority is Load-Battery-Utility. Since I'm maintaining a high SoC of the battery already, I want it to primarily focus on loads. As I noted earlier, it still trickle charges the battery, which has proven to be more than enough to get back near 26.5V.

Output source priority is Solar-Utility-Battery. This tells it to feed the load it can't take care of with Solar using utility. This is key to not draining the battery when utility is up. Note that I do see some low discharging in the evening, typically 1-2A, which is how it comes down to 25.4V. Not sure why it does that, but because I can limit it via the next setting, it's not an issue.

Battery re-charge voltage when utility is available is 25.5V. This is as high as you can set it. And, it's fine. I haven't figured it out, but I suspect the SoC of the bank is over 80% there, well within my requirements. This is the key that ensures my batteries stay high when I have no PV input.

Note that another reason I do this is because I suspect converting from AC to battery then back to AC is inefficient. Directing utility directly to loads, if it does not do these conversions, should be pretty efficient. I haven't proven it operates how I expect here. But, for now, I'll hope that's what it is doing until proven otherwise. So, minimizing battery cycling should prolong their life as well as maximize efficiency of utility power.

When I get all 6 panels online, I'll also be monitoring impact to my electric bill. It should go down some. We'll see.
 
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UPDATE: I woke up this morning to discover that the inverter shut off at 3:45am due to low voltage. One of my assumptions was incorrect... it did not use AC to keep the bank above 25.4V. To attempt to remedy, I'll switch the Charging source priority from Solar only to Solar First.

On the plus side, this gave me an opportunity to bottom balance the bank with my 12V AC charger, as 2 batteries were lower than another two. This is where the Lion Energy kicks butt, because the built-in meter appears to be a better guide than merely reading the voltage, as a quick charge will shoot up the voltage at idle, and I don't want to wait a long time for it to settle as that will waste a sunny day.

This also verified that it was able to cut off the inverter before the battery BMS cut off in the Lion Energies, as they all read voltage over 12.5V. Reached out to Will to get his input on using the LED meter vs a voltage meter after a quick charge.
 
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UPDATE: I switched the Charger source priority setting from Solar only to Solar first. When I had Solar only, it did not kick on AC charging even during the window that I have set. But, with Solar first, it kicked on when the 1hr window I have set came around.

I'm really trying to avoid AC charging, so that isn't ideal. But, I'll leave it on this setting until I see sunny days. What I'm trying to determine is how this impacts PV charging and how it uses utility.
 
UPDATE: I found a configuration that seems to really minimize battery discharge. The only downside is it really really wants to keep charging it until the end of time. So, not done tweaking.

Also, there does not seem to be a way to prevent AC charging with the Solar first setting. But, you can minimize it by limiting it to 1 hour and setting it to 2 or 10A. Because I expect 2 rainy days, I have at 10A for now.

Note that in Solar power priority, I have Battery as #1 destination. In Output source priority Battery is last. I just need to narrow down now which of these settings has stopped it from discharging the battery when Utility is available, and find a way to ensure more PV goes to load. I'll switch Solar power priority back to Load-Battery-Utility and see if that reaches my utopia.

1586441818625.png
 
UPDATE: Changing Solar power priority to Load-Battery-Utility had an immediate impact of directing more PV to the load. You can tell because while it is still charging the batteries, unlike yesterday, it is only a portion of PV production. Just multiply amps by 24V. It's been putting 24-48 watts into the batteries while producing over 100W. (Note that it is 100% cloudy, so this is horrible production. But, that doesn't change the test results.)

Now I just need to confirm that this didn't increase battery discharging. That doesn't really become visible until PV production is 0... at night.

1586443663216.png

I added load to it to, and as the sun begins to push more light through the thinner clouds, you can see that only a small portion is going to the batteries; thus, a higher percent going towards load:

1586444390335.png

It's been sending 12-25% to the batteries, so 75-87% to the load.
 
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No matter what I set mine to I can't make it do Solar First.
So to fix that, I unplug the A/C as a source.

No matter what now, the inverter can only charge the battery or supply some A/C from the sun and battery.

If the battery gets too low and it's a cloudy day, I can then plug the grid back in. Or go without pure clean power until tomorrow. :)

My favorite thing to see is when the loads needed are less than what the panels are providing AND the panels are charging the batteries!
(I just saw my panels send enough current to charge my car and charge the batteries at the same time)
 
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No matter what I set mine to I can't make it do Solar First.
So to fix that, I unplug the A/C as a source.

No matter what now, the inverter can only charge the battery or supply some A/C from the sun and battery.

If the battery gets too low and it's a cloudy day, I can then plug the grid back in. Or go without pure clean power until tomorrow. :)
It didn't do AC charging when I selected Solar only. The problem I had with that was it wasn't sending enough to the loads. If I'm in a high SoC, then the battery is not my priority during peak production. Loads are. I may go back to retrying it after I find a near perfect balance with Solar first.

And you're right. Solar first does not stop AC charging. I did notice in one of your videos that you had AC charging limited to 10A. That's where I am now. I've used the timer feature to always limit when it can turn on, and that has always worked. 1 hour is minimum. So, for you, that's about 480WH per day. For me, 240WH. Mine also has a 2A setting, which would reduce yours to 96 WH/day. Does yours have a 2A option?

My AC IN is a dedicated circuit in my main, so I can just flip that breaker if I need to cut it. But, I really like being able to remotely toggle things via VNC instead of going down to the basement to flip a switch. Currently, I only have to do that for the 10 circuit transfer switches if I want to change the loads on the inverter. I just reached out to HighTechLab about replacing that with PLC so I can both remote control it and intelligently automate it to create Smart Solar. :)
 
The setting is 10A - per inverter, so it's actually 20A total going to the batteries for the lowest settings.

I have the dedicated circuit also, I use it as both supply and to receive energy. I back feed the circuit to supply my house. 1st I turn the main to the house off, then flip the circuit on, and now the batteries/inverter supply my house.

I was using Teamviewer on the laptop, but TeamViewer somehow thought I was using for commercial purposes, now I use Anydesk to remote in on the laptop monitor.
 
It didn't do AC charging when I selected Solar only. The problem I had with that was it wasn't sending enough to the loads. If I'm in a high SoC, then the battery is not my priority during peak production. Loads are. I may go back to retrying it after I find a near perfect balance with Solar first.

And you're right. Solar first does not stop AC charging. I did notice in one of your videos that you had AC charging limited to 10A. That's where I am now. I've used the timer feature to always limit when it can turn on, and that has always worked. 1 hour is minimum. So, for you, that's about 480WH per day. For me, 240WH. Mine also has a 2A setting, which would reduce yours to 96 WH/day. Does yours have a 2A option?

My AC IN is a dedicated circuit in my main, so I can just flip that breaker if I need to cut it. But, I really like being able to remotely toggle things via VNC instead of going down to the basement to flip a switch. Currently, I only have to do that for the 10 circuit transfer switches if I want to change the loads on the inverter. I just reached out to HighTechLab about replacing that with PLC so I can both remote control it and intelligently automate it to create Smart Solar. :)

The PLC likely wouldnt be able to allow you to toggle things remotely (Assuming wires running to a remote location is considered "remotely") rather you would need an HMI that connects to the PLC via ethernet. you can then connect to the HMI via the internet to control from a phone or such. But I digress....It would be interesting to see what you are trying to replace with the PLC.
 
It would be interesting to see what you are trying to replace with the PLC.
This basically:

https://www.homedepot.com/p/Relianc...ircuit-Manual-Transfer-Switch-A510C/206503336

What this controls is what loads are on my inverter (GEN) vs directly on utility. Right now, I have 3 flipped to GEN, for instance. The fridge, some servers, and part of my living room. Normally 400-500W. I just looked and over 800W, which means the fridge defroster is running.

So, basically an A/B transfer switch what works with 20A 120V is what I need from PLC.
 
@HighTechLab I haven't played with it. I did look into it a bit. Seems to be primarily serial communications. There are APIs you can use in many languages, such as Java. I'm not sure where they need to rest. But, even if they have to be hard wired, that's fine. Because as soon as I can talk to it programmatically via a standard language, I can expose it via my own API that I can then access from a browser anywhere in my home via local LAN (or in the world if I secure it). I typically create RESTful services and use Web Sockets, both of which are available in the browser.

Would this Node library work with the PLCs you are using today? Node is my preferred server side platform today. I then use Angular to create rich UIs that run in the browser to connect to these back-ends.

Any 24/7 "smart" automation would run on the server side. The browser side is purely for user interface. But, you can stream real-time data to it via Web Sockets. I have such an application that, for instance, does real-time streaming of market data. This is useful for sensors and interacting in real-time.

This is a screenshot of my trading UI running in the browser. While this is a screenshot, these numbers are continuously updating:

1586462533262.png

This application is online if you want to try it. You'll need a TDA account.
 
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@HighTechLab I haven't played with it. I did look into it a bit. Seems to be primarily serial communications. There are APIs you can use in many languages, such as Java. I'm not sure where they need to rest. But, even if they have to be hard wired, that's fine. Because as soon as I can talk to it programmatically via a standard language, I can expose it via my own API that I can then access from a browser anywhere in my home via local LAN (or in the world if I secure it). I typically create RESTful services and use Web Sockets, both of which are available in the browser.

Would this Node library work with the PLCs you are using today? Node is my preferred server side platform today. I then use Angular to create rich UIs that run in the browser to connect to these back-ends.

Any 24/7 "smart" automation would run on the server side. The browser side is purely for user interface. But, you can stream real-time data to it via Web Sockets. I have such an application that, for instance, does real-time streaming of market data. This is useful for sensors and interacting in real-time.

This is a screenshot of my trading UI running in the browser. While this is a screenshot, these numbers are continuously updating:

This application is online if you want to try it. You'll need a TDA account.

Quite honestly, you lost me somewhere at hello.

The PLC can communicate by rs-232, rs-485 and Modbus-tcp.

Using Modbus-tcp you can pull data out of it over ethernet, but how your server connects to the modbus-tcp is something that I have no experience with. I use a C-More HMI that I can log into remotely and just monitor my data via remoteHMI. I see what you are trying to do but I did it with off-the-shelf parts and all I did was wrote some ladder code to handle generator running and such.
 
Quite honestly, you lost me somewhere at hello.

The PLC can communicate by rs-232, rs-485 and Modbus-tcp.

Using Modbus-tcp you can pull data out of it over ethernet, but how your server connects to the modbus-tcp is something that I have no experience with. I use a C-More HMI that I can log into remotely and just monitor my data via remoteHMI. I see what you are trying to do but I did it with off-the-shelf parts and all I did was wrote some ladder code to handle generator running and such.
Where I get lost is the vendor flavors. So, from that Node link,
The Hilscher Node-RED node-red-contrib-s7comm node is designed to communicate with a SIMATIC S7-300/1200/1500 PLC of SIEMENS based on the RFC1006-communication protocol. The S7comm node can build up a connection with the SIMATIC-S7. Furthermore it can Read/Write Addresses of the PLC with specific S7-Datatype.
It appears SIEMENS has their own implementation of PLC. You see some attempt at standardization with things like "S7-Datatype". But, is that SIEMENS specific or recognized by most of the PLC vendors? IDK. I was hoping you can shed light on vendor choices and standards.

RS-232 is serial communications... pretty much where it was born as far as I know. A very popular port in the 1980s you don't see as often on computers anymore. Bluetooth also supports serial communications. Two android phones connect, and they are using serial over bluetooth. From a programming perspective, you receive bytes, you send bytes. A protocol then defines the language you speak. Having a PLC library can handle a lot of that dirty work, hopefully making it easier. But, if I have to, I can go to the lowest level. I did a lot of that way back in time.

I get how using the HMI can give you the basic operations, namely viewing output such as sensor data and pressing a button to send an action. I want to go further, so I'll need to write code that can do it all. I want it to learn (such as the load profiles for each AC circuit) and use that data to make decisions. So, for instance, if the grid goes down, it will know to begin critical load mode, which could be a step down based on battery levels. Conversely, if it sees that you are generating more PV than you are currently using, it might switch additional load to GEN to absorb that.

I may start with an HMI. The price seems a little high considering that I'll be replacing its functionality with a web browser based application.

While my goals are a little different than yours, I'm hoping you can help me on the hardware selection and knowing what can be done in PLC. So, for instance, if I want a PLC controlled 120V A/B switch/relay. Where do I start?
 
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@HighTechLab I've begun watching the PLC learning videos provided by Automation Direct. Thanks for the tip on the site!

Do you have a parts list of what you used? That could help me connect dots.
 
Erik--

Can you PLEASE confirm the following on the LV2424 unit...thnx.

There seems to be two different software packages for the All-In-One MPP units:

1) LV5048 -- WatchPower software
2) LV2424 -- SolarPower software

As I glance at both manuals-- They are a bit different and several "time/cost-shifting" parameters do not exist within the WatchPower software.

However--

The online documentation for the SolarPower software is also a bit unclear on just what the "Off-Peak Duration" setting controls.

The setting provides a place to enter clock start/stop times.

Can you PLEASE confirm that this parameter is used to define a window (start time/end time) when the unit will "ask" the Grid to charge the battery bank and the unit will not try to charge from the Grid outside of this window....???

THANK YOU.
 
Erik--

Can you PLEASE confirm the following on the LV2424 unit...thnx.

There seems to be two different software packages for the All-In-One MPP units:

1) LV5048 -- WatchPower software
2) LV2424 -- SolarPower software

As I glance at both manuals-- They are a bit different and several "time/cost-shifting" parameters do not exist within the WatchPower software.

However--

The online documentation for the SolarPower software is also a bit unclear on just what the "Off-Peak Duration" setting controls.

The setting provides a place to enter clock start/stop times.

Can you PLEASE confirm that this parameter is used to define a window (start time/end time) when the unit will "ask" the Grid to charge the battery bank and the unit will not try to charge from the Grid outside of this window....???

THANK YOU.

SolarPower time settings:
1586895778382.png

I use the first one. It will ONLY charge the batteries from utility during that time frame if set. 00:00 to 00:00 is the same as always on. I have not touched the AC Output setting. You can only set it in 1 hour increments. The minutes will always be '00'.

When it is AC charging, it will use the amps you designate:

1586896451449.png

I can confirm it will only charge the batteries from the grid during the time set if you set it (not all zeros). However, it can still send utility (AC IN) power to loads from the grid independent of this setting if you are not sending enough PV production to it at any given moment, either because you are not producing enough, or because you prioritized battery charging over loads. The time setting ONLY impacts battery charging, not loads.

You can also disable AC charging with this parameter:

1586895954199.png

By setting it to Solar only. When I tested that setting, the time setting didn't matter. AC charging never kicked on during the time I had it set for. It does matter if you select one of the other two options, such as the Solar first option I currently have selected.

Note that these two settings, while not as black and white, play a huge role in how it charges and discharges the batteries:

1586896025266.png

For example, if you want to minimize loads being fed from utility, using your battery instead, you'd set the output source priority to Solar-Battery-Utility. If you do that, though, you had better be sure you have enough PV to recharge those batteries before they die. You can get pretty close to emulating true off-grid with the settings. Although, the obvious way to emulate it is to simply turn off AC IN (mine has a dedicated breaker.)

I personally prefer to let AC feed loads as needed, and try to minimize using AC charging the batteries due to inefficiency in the conversion. I don't produce nearly enough to replace utility power. So, my goal is to primarily maximize PV utilization while keeping my life smooth and happy, using PV to charge batteries as needed, and to help feed loads when batteries are near full.

Note that when you don't have PV, you'll have some drain on your batteries from the inverter. You'll need to do some battery charging every day. If you don't have too many cloudy days you can try to do this all with PV. You'll just want to plan some of your PV production to go to battery charging every day to offset this if you don't want to allow AC charging.
 
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Do you have a solar panel combiner box/circuit breaker between the MPP and solar panels as Will shows? If so what size breaker? Will does not show this in his video only direct connect to panels.
 
This is a very interesting thread! My LV2424 Hybrid is on it's way. I agree for the price point it can't be beat!

Do you have a solar panel combiner box/circuit breaker between the MPP and solar panels as Will shows? If so what size breaker? Will does not show this in his video only direct connect to panels.

A breaker between your panels and MPP is a good idea as it serves to both protect your system and act as a PV disconnect. Your panels should be the first thing you disconnect and the last thing you reconnect when you service your system. Flipping a handy breaker makes that super easy. YOUR breaker should be sized according to your panels. If your panels generate 7 amps each and you have two in series that's 14 amps and a 15 amp breaker will work. I have 17 amps protected by a 20 amp breaker in my system. Make sense?
 
This is a very interesting thread! My LV2424 Hybrid is on it's way. I agree for the price point it can't be beat!



A breaker between your panels and MPP is a good idea as it serves to both protect your system and act as a PV disconnect. Your panels should be the first thing you disconnect and the last thing you reconnect when you service your system. Flipping a handy breaker makes that super easy. YOUR breaker should be sized according to your panels. If your panels generate 7 amps each and you have two in series that's 14 amps and a 15 amp breaker will work. I have 17 amps protected by a 20 amp breaker in my system. Make sense?
If just one string, the baby box ($37) with a 150DC DIN midnite solar breaker ($17) works great. Note that it is an indoor box. Works well with 10 AWG. I have notes on the gauge limits on their breakers if anyone needs more detail. I also found a cost effective path for the combiner box, rated for outdoor if you need it.
 
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