BradCagle
Solar Enthusiast
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yes. but it was reading 9 when I know it should be 35
A little disappointed with my new Growatt SC48120-MPV charge controller.
- Thread starter syclonedriver
- Start date
syclonedriver
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that's a problem
Darren67-72
Off grid
Hot off the press, (haha) it seems some server rack batteries are having communications issues with inverters and likely mppt's, if the batteries are not grounded to the system.
On lifepo4 batteries, this can be done with the supplied battery to server rack bolts.
This is something I guess is not well known.
On lifepo4 batteries, this can be done with the supplied battery to server rack bolts.
This is something I guess is not well known.
whiteshepherd
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Well got another little surprise today. I have my sc48120 max voltage set for 29.2v. However because one of the batteries was a little out of balance the BMS kicked in and stopped charging. At that point the charge controller put 64v across my batteries and inverter. Blew the $600 inverter to kingdom come with the internal caps exploding. I had never had a charge controller use more than max voltage to charge. However the guy from Watts 24/7 told me this was normal and the danger running batteries with BMS. He said he recommended running an "analog" battery in parallel with my LiFePo4 batteries. In 10+ years of running EPEver I never once had high voltage put on my battery line. If this is everyday normal? I guess I will put a 36v bank of super capacitors across my inverter power. They should absorbed the 1-2 second high voltage spike before the Growatt corrects itself. 
Watts247 - Ian Roux
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Why build something when Solar Assistant can pull data from these devices already ?
Calibration Video:
Modbus Registers:
Ian
Watts247 - Ian Roux
New Member
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Why build something when Solar Assistant can pull data from these devices already ?
Calibration Video:
Modbus Registers:
Ian
syclonedriver
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T
When I clicked set it did nothing.
I'll try again.
Thanks for the video.Why build something when Solar Assistant can pull data from these devices already ?
Calibration Video:
Modbus Registers:
Ian
When I clicked set it did nothing.
I'll try again.
Watts247 - Ian Roux
New Member
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Why build something when Solar Assistant can pull data from these devices already ?
Calibration Video:
Modbus Registers:
Ian
were the bar graphs active like in the video ?
NewGuyNoob
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Ian, [@MPP Solar USA - Ian Roux ]Why build something when Solar Assistant can pull data from these devices already ?
Calibration Video:
Modbus Registers:
Ian
Do you know if Solar Assistant can pull from more than one of these SCC and show this in one display? Or would I need to purchase 2 Solar Assistant Licensees and use 2 separate Raspberry Pi's to pull from two SC48120-MPV, then combine them Via MQT and Home Assistant?
can pull from multiple with one license
Watts247 - Ian Roux
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one solar assistant for many (haven't tried it on multiple SC48120 but know the developer well enough to fix this if it doesn't) , this is the way it works for multiple inverters in one system (which I have tried, as I use it for my home with 5 inverters) - one USB port per device, you can use a USB hub to link to many devices such as batteries, inverters etc
NewGuyNoob
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I have tried multiple times to have two inverters shown.
Maybe I should PM you?
But I have tried EG4 6500ex and a Growatt inverter.
It will only show one inverter. I can do both inverters independently, but not at the same time.
I thought I read on the SA website help, that you could only do more than one if the inverter was in parallel.
Mind if I pick you brain on your setup?
syclonedriver
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YesWhy build something when Solar Assistant can pull data from these devices already ?
Calibration Video:
Modbus Registers:
Ian
were the bar graphs active like in the video ?
I am using it in a 24 volt system. I wonder if that has something to do with it. Maybe setting it to 50v will actually set it to 25v in my application.
Watts247 - Ian Roux
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If you have a charge controller that is designed for 48V 24V and 12V (auto sensing) , and you have high PV input, and the battery may be 24V as is in your case, and the battery goes open circuit, the auto sensing is going to think that perhaps these are 48V batteries.Well got another little surprise today. I have my sc48120 max voltage set for 29.2v. However because one of the batteries was a little out of balance the BMS kicked in and stopped charging. At that point the charge controller put 64v across my batteries and inverter. Blew the $600 inverter to kingdom come with the internal caps exploding. I had never had a charge controller use more than max voltage to charge. However the guy from Watts 24/7 told me this was normal and the danger running batteries with BMS. He said he recommended running an "analog" battery in parallel with my LiFePo4 batteries. In 10+ years of running EPEver I never once had high voltage put on my battery line. If this is everyday normal? I guess I will put a 36v bank of super capacitors across my inverter power. They should absorbed the 1-2 second high voltage spike before the Growatt corrects itself.
1) Battery communications to Charge controller/bms is a over discounted thing. Old fashioned analog batteries never did go open circuit , like modern BMSs. Running a Lithium battery without comms is a huge source of problems in many directions
2) (Speaking Generally) Another thing is most folks buy huge number of solar panels, huge 6.5 or 12kw inverter and then buy a tiny cheapest 5.1kwh battery they can find (what makes it worse is this battery does not have bms comms to the inverter, so the inverter had zero idea on state of charge, charging amps etc) Then the massive amount of solar charges the battery at a huge rate, trips the BMS, battery goes open circuit, all these KW of solar have to go somewhere, this energy surge can kill the inverter, we see it time and again.
This is for the general audience:
3) Tips, never charge your Li battery near 100% for this reason. (Same reason Tesla only trickle charges the last few %, but never charges them to true 100%)
4) Buy a battery that DOES communicate with your charge controller/inverter.
5) Have more battery than Solar
If we compare a 5 gal bucket of water to a 5kwh battery, filling it with a hose, as it gets near the top, you slow the flow to top it off without messing (BMS comms) but if you are not there to monitor, you just open the hose to full and walk away ( no feedback) you come back to a huge puddle.
Also another visual , 5 gal bucket in a rainstorm (tons of solar) with water ( amps) belching off the roof, your 5 gal bucket (battery) will be full in seconds with a but never be able to fully charge to the top, as the splashing also empties the bucket. So a quick charge damages the battery, cannot fully charge the batteries, and shortens the life of the batteries.
Hence. If possible, put Analog batteries in parallel with your lithium's to prevent this (Silicate Gel works very well)
Another thing, lithium batteries can go open circuit when under load (protection) especially if you have too few for that huge inverter, this also damages inverters. Its akin to turning off your Diesel motor by pinching the fuel supply, which can destroy the fuel system ( the inverter)
Please dont buy batteries just because they are cheap(er) or your favorite YT guy says they are great and "who needs BMS communications"?.
BMS comms are essential.
Now if you have tons of battery supply, BMS comms becomes less important.
Another workaround is if you have already purchased batteries that dont communicate, then the next time, buy some that are compatible with your Inverter, Make sure battery voltages are compatible , and parallel the new batteries with the others (get them to same level of charge first - another topic) , at least you will have some intelligent feedback.
My 5 sents could save you 1000s
Thanks for your information in your post.
Perhaps instead of auto sensing there should be a battery voltage selector switch. Or more simply units designed for only one battery voltage.
Watts247 - Ian Roux
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yes, but directly, this forum will keep a single man busy for years, and I neither have the time or the inclination.
I hardly ever read posts here.
whiteshepherd
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- Apr 1, 2022
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Thanks for your reply. The calibration software for me doses not work. Everything looks exactly the same as the calibration video including the com port tx/rv bars. But when you click "set voltage" it changes nothing (I'm using 24v battery bank). I wish I had bought EG4 batteries. But at the time they were a lot more expensive. The EG4s have come down in price a LOT. But I got what I got now. Six 200Ah Enjoybot LiFePo4 batteries with 200Ah BMS charged by a 3.4kW solar array. Enjoybot recommends a charge voltage of 29.2V for my bank. User battery setting in the Growatt only really has two options charge voltage and float voltage. After my dead inverter I reduced my charge voltage to 28v and float to 27. What charge settings would you recommend for 24v LiFePo4 to reduce risk of a blowout? I have also purchased active battery ballencers for all my batteries which should be here in a few days.
As far as Solar Assistant I own several Raspberry Pi4s (one tracks my solar PV and battery voltages and posts it to hte bottom of my web page https://inlightof.us ) from before the pandemic so I purchased the program and wrote it to a SD card. It seems to connect with SPA. But Solar Assistant reports back weird values like my solar is 10billion volts, etc. Anyone else get Solar Assistant to work with this sc48120?
Where did you find this info? Are you saying you need the negative to be bonded to ground?
Darren67-72
Off grid
Long story but, I was helping trouble shooting a charge limit cap on a S.S. setup and we found that this particular individual had forgot to ground bond his batteries (either through wire, bolt, case, or other means) with the lack of ground, the communication between batteries and/or inverter was not in connection. Because the inverter and ALL the batteries do not com. the safe default with the "Li" will be 50amp, as if only one battery is hoocked up.
Darren67-72
Off grid
And, no... you do not need to bond battery negative with ground. Although some people do. I wont argue some people's safty thinking.
