diy solar

diy solar

MPP-SOLAR LV6548

I'm well aware. But everyone has an opinion.

Not meant to criticize so please accept as intended.

There is some science behind that particular opinion as detailed in the article so I just wanted to put it out there for others reading the thread and making their own decisions.
 
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Not meant to criticize so please accept as intended.

There is some science behind that particular opinion as detailed in the article so I just wanted to put it out there for others reading the thread and making their own decisions.
Absolutely, no worries. ?
 
DMI inc is using 4 of them and 3 DIY batteries to power his entire house. No grid tie. He monitors everything via raspberry Pi. 26KW of AC is not bad for $4400 worth of inverters, that also include a transfer switch, battery input, multiple 120a MPPT outputs, 32KW of PV input, and very simple cabling.

I am thinking of removing my SMA grid tie and doing what DMI is doing instead with the MPP LV6548's. It seems like a much better solution, as your solar is always available, even in grid down, and you can always just plug in the grid or a generator as an extra input to the LV6548's if there is no sun for a few days.

What am I missing?
If you already have grid tie sma inverters and want to go off grid. I would suggest adding a sunny island sma inverter and make your own micro grid.
 
If you already have grid tie sma inverters and want to go off grid. I would suggest adding a sunny island sma inverter and make your own micro grid.
That was my first inclination, but I would need two of them for 240V, plus some MPPT chargers and more panels. Sunny Islands are now about $3800 each, while the MPP inverters are about $1200 each.
So $7600 vs $2200 for about the same wattage.
 
That was my first inclination, but I would need two of them for 240V, plus some MPPT chargers and more panels. Sunny Islands are now about $3800 each, while the MPP inverters are about $1200 each.
So $7600 vs $2200 for about the same wattage.
I agree the price point of the MPP inverters is pretty compelling ( I currently have 2 lvx6048 inverters).

I don't know if I understand you fully. Are you planning on adding more, solar?

Another point if you went with the sunny island inverters, they form a micro gird, and are ac cupling compatible. So they will absorb the extra energy from your grid tie inverters and charge the batteries.

There for your overall capacity would be the sunny island inverters plus the solar input.

Just some thoughts.
 
I agree the price point of the MPP inverters is pretty compelling ( I currently have 2 lvx6048 inverters).

I don't know if I understand you fully. Are you planning on adding more, solar?

Another point if you went with the sunny island inverters, they form a micro gird, and are ac cupling compatible. So they will absorb the extra energy from your grid tie inverters and charge the batteries.

There for your overall capacity would be the sunny island inverters plus the solar input.

Just some thoughts.
Like I said, I would love to use Sunny Island if the price was better. I thought they needed midnight solar chargers though.
My Sonny Boys are from 2008, so 13 years old. I think its time to put them to rest.
 
I thought about doing the same thing with the LV6548 s but would need 2 and would want to have a backup so 3 but then if had problem it may affect both so 4 and use 2. (actually wanted 2 of the LVX6048 but they were not going to be available for a while) I already had 1 LV5048 and had another location I wanted a small system at so I bought 2 of DMI s old LV5048 s (cost less than 1 LV6548) and use 2 here and 1 at another location . This way I should always have one spare for here though not as much a problem if one goes out since all are split phase.
I will eventually upgrade . Maybe when the LVX6048 s are easily available or something like the Deye units in a year or 2 and then someone could get heck of deal on 2 or 3 LV5048 s . I would rather have about 15 to 18kw max continuous inverter available at least until I get a heat pump dryer. For now 10-12Kw is enough I just make sure I turn off one of the AC units when drying clothes and dryer is right next to panel.

BTW I put my inverters at opposite end of house from service panel because it made the PV run much shorter (important with max 145v PV input) and used the wiring that had gone to the HVAC units which were 60 amp circuits (for old units) for the grid input and Inverter output to the service Panel. There fore no new long wire runs and inverters connected to rest of whole house . I do have 2 service panels that were already in house a 200amp and a 300 amp. The 100 amp was for a garage/workshop . Now I can set up a "super critical " loads panel if I wanted. Also minimized power loss its long wire run to HVAC units about 15 feet away.
 
I thought about doing the same thing with the LV6548 s but would need 2 and would want to have a backup so 3 but then if had problem it may affect both so 4 and use 2. (actually wanted 2 of the LVX6048 but they were not going to be available for a while) I already had 1 LV5048 and had another location I wanted a small system at so I bought 2 of DMI s old LV5048 s (cost less than 1 LV6548) and use 2 here and 1 at another location . This way I should always have one spare for here though not as much a problem if one goes out since all are split phase.
I will eventually upgrade . Maybe when the LVX6048 s are easily available or something like the Deye units in a year or 2 and then someone could get heck of deal on 2 or 3 LV5048 s . I would rather have about 15 to 18kw max continuous inverter available at least until I get a heat pump dryer. For now 10-12Kw is enough I just make sure I turn off one of the AC units when drying clothes and dryer is right next to panel.

BTW I put my inverters at opposite end of house from service panel because it made the PV run much shorter (important with max 145v PV input) and used the wiring that had gone to the HVAC units which were 60 amp circuits (for old units) for the grid input and Inverter output to the service Panel. There fore no new long wire runs and inverters connected to rest of whole house . I do have 2 service panels that were already in house a 200amp and a 300 amp. The 100 amp was for a garage/workshop . Now I can set up a "super critical " loads panel if I wanted. Also minimized power loss its long wire run to HVAC units about 15 feet away.
Sounds like a nice setup! I find the AC side is more difficult than the DC side.
 
Sounds like a nice setup! I find the AC side is more difficult than the DC side.
I did an interesting load test yesterday. Since the MPP' supply PV power to loads along with the batteries, I wanted to see what battery alone would do with 2 LV6548's in parallel( one per phase, but not in split mode yet). So I switched off the PV input, and tried to put enough load on the units via battery only to shut them down.
This setup is only connected to my barn, which is my workshop, but has an apt on top. So I turned on all the lights, a heater, the air conditioner, the TV, fridge, all my chargers, my nail gun compressor, ans my dewalt table and chop saws. The fans spun faster, but I could not bring them to their knees. I guess I dont have over 13KW of stuff in the barn.
It was nice to see that those Lifepo4's with the Heltec BMS worked well, and the MPP LV6548's shrugged off the load.
Next test is to finally get the units in split phase, and then add in my 240V Arc welder at the same time.
So far so good! I am top balancing the second bank of cells now, so will have 28KW of battery when done. As soon as I get my shipment from Michael, I will need to redo all my batteries onto a shelf like Andy in off grid garage, as that will add two more 16s banks for a total of 64 cells. Damn this is fun!

As this is proving out really well, I will be repeating the process for the house I just bought in Charleston SC, and removing the existing 13 year old SMA Grid Tie sunny boys with MPP.
 
Finally charging the CATL cells that came in in 12V banks to get ready to top balance. Some of the cells came in with higher DOC than others, so I will need to monitor carefully.
I just saw on one of the threads here that Deye inverters will have a US version and be available here shortly, or even now! That means I should be able to get Sol-ark capabilities at close to MPP prices shortly! I would love to see a head to head bakeoff between the Deye 8k and the MPP LVX8048WP!
 

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Holy crap. I just installed the Ve direct to USB cable to the Raspberry Pi running Solar-Assistant.io software. Sooooo much simpler than coding it all in Python. Works perfect! I am now getting great battery SOC. All I am missing is individual cell voltages, so I will continue with getting comms working with the Heltec/JK BMS.
I just want to say thanks to everyone on this forum who have helped me to get to where I am. I have learned so much in such a short period of time. My wife is amazed too. You guys rock!
 
Question: Is it possible to run a sub 1kW load on the LV6548 using 2 battle born batteries in series or is the amperage demand from startup of the inverters and fans too much for that battery configuration? IK this thread is old, sorry to be annoying and thanks in advance
 
Question: Is it possible to run a sub 1kW load on the LV6548 using 2 battle born batteries in series or is the amperage demand from startup of the inverters and fans too much for that battery configuration? IK this thread is old, sorry to be annoying and thanks in advance
No, the battery has to be 48v configuration.
 
Question: Is it possible to run a sub 1kW load on the LV6548 using 2 battle born batteries in series or is the amperage demand from startup of the inverters and fans too much for that battery configuration? IK this thread is old, sorry to be annoying and thanks in advance
Like Jason said, you will need 4 battle born batteries to make 48v.

Sub-1kw load is very easy to do. 4 Battleborn batteries should sustain a 5000watt load with ease, just not for very long before it runs out of capacity.
 
No, the battery has to be 48v configuration.
Question: Is it possible to run a sub 1kW load on the LV6548 using 2 battle born batteries in series or is the amperage demand from startup of the inverters and fans too much for that battery configuration? IK this thread is old, sorry to be annoying and thanks in advance
Agree the answer is No unless you have 2 24 v batteries. The problem would likely never be the startup for the inverter or a sub 1,000 watt load. You must have a 48 volt battery system though. 4 inexpensive lead acid 12 volt batteries would work but you would be limited in capacity to about half their rated amp hours .
 
Question: Is it possible to run a sub 1kW load on the LV6548 using 2 battle born batteries in series or is the amperage demand from startup of the inverters and fans too much for that battery configuration? IK this thread is old, sorry to be annoying and thanks in advance

Actually...

You can run ONE LV6548 in 120V configuration without any battery at all. I forgot that the LV6548 does have a "battery-less" operation function.

  • Batteryless operation (single unit mode only)
 
Actually...

You can run ONE LV6548 in 120V configuration without any battery at all. I forgot that the LV6548 does have a "battery-less" operation function.

  • Batteryless operation (single unit mode only)
I actually did this for testing, and its quite impressive what its capable of with batteryless and PV only. With 6kw of incoming PV, I was able to slowly turn on all 3 AC units in my RV. The first one was no problem, the 2nd one you could tell was a bit of a strain, and the 3rd one definitely hit it hard and the fan speeds slowed a lot for a second or so, but it was able to maintain it and it actually worked.
 
Actually...

You can run ONE LV6548 in 120V configuration without any battery at all. I forgot that the LV6548 does have a "battery-less" operation function.

  • Batteryless operation (single unit mode only)
Yes but several other 48 v inverters that are split phase 240 volt can also supply power without batteries but of course ONLY while the sun/pv power is available.
 
Question: Is it possible to run a sub 1kW load on the LV6548 using 2 battle born batteries in series or is the amperage demand from startup of the inverters and fans too much for that battery configuration? IK this thread is old, sorry to be annoying and thanks in advance

48v battery is needed. The lowest draw I have witnessed is 49watts at night and confirmed on Batrium K9

If you want 24v then your cable will be bigger and you need a 24v MPP

In RVs the 50amp isn't really 240v just two 120v legs to all the 120v appliances. I have one inverter feeding the breaker panel and a pigtail from one leg of the bar over to the second to power the second leg of the panel and it has worked perfectly. Youtube has videos. We have had AC 2kw, microwave 1100w, 115v well pump 650w, 750w fridge, 350w RV fridge, RV water heater 1500w until warm, LG washer dryer combo. They are all running, all the time, all summer, when ever we want, with no issues. I do tell my wife to just run one item at a time e.g not to run the hair dryer along with the coffee maker or microwave encase all the other items are running. We have 32cells 16s2p to make 48v system. I think the most I have witnessed on the PC is 4900 watts being drawn .
 
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