Setting up a Solax Inverter

[Barge17]

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Good afternoon,

A friend of mine has recently updated his system and passed on to me his redundant SK_SU3700E inverter and Darfon battery which I am checking over and plan to set it up for time - shift energy storage.

It might be still registerd in his name with Solax, so do you think it best for me to get in touch with them to make changes?
I have not had any luck trying to register it with its serial number. I'll check with my friend first.

Thanks for your help, David
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[Barge17]

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I have started to balance the cell pack voltages with a regulated PSU and am getting them closer, but its surprising how long it takes, the voltages are as below - how close do they need to be before I start suspecting the BMS has locked out and is unusable?
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this is the plate on the battery, I thought it was Solax, but now think it is probably Growatt and possibly not worth spending time or money on?
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[Tinbum]

They are not bad batteries, just let down by the bms that locks out on errors and has to be reset. Someone on ebay offers that service. They are now coming up on ebay quite cheaply in comparison to what they were.

Darfon made them for Growatt.

[Barge17]

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Thank you tinbum, for that, I had seen the ebay advert and thought it might be good money after bad. Do you know if they lock out in normal daily use with an invertor? That is what happened to it with its previous owner and he didn't give it a second chance. It does look a well built battery though, and most of it has held its charge for 12 months now.
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How close to I need to get the voltages balanced before I connect it with a reset BMS board, if thats the route I go down?
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[Barge17]

Good Morning,

I have had the BMS reset and got the cell packs all balaced around 3.9v.

We gave the BMS its first try yesterday and it is looking promising so far, however there is no voltage on the BMS output. The battery is showing 55.3 volts before the BMS and there are no LEDs showing at present on the inverter, the green flashing has stopped, but it does show the power output / input to the grid.
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I am going through the instruction manual now, not that easy to follow, but won't change anything without advice. Attached is a quick video:
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from http://www.toggenberg.co.uk/wp/wp-conte ... Manual.pdf, the following screenshot which suggests that the battery is over voltage at 55.3, but how that can be right? It's about 18 months since the battery side of it stopped working, but the solar panels were still generating for a few months after that, then the units were stored..
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[Kommando]

however there is no voltage on the BMS output

Is the battery anything like this one



If so then likely the BMS has a fault

[Tinbum]

I'm pretty certain the battery will not turn on its output if it hasn't received the right message from the inverter. I had a couple of those batteries with the Growatt SP2000 inverters and looked into the possibility of using the batteries with a Sofar ME3000SP inverter.

I tried sniffing the messages between the SP2000 and the battery in order to make a 'message translator' but never pursued it. I've since gone on to use modern Growatt batteries with the ME3000SP and am just finalising the 'CAN translator' software which seems to be working brilliantly.

[nowty]

I bought up 10 of those batteries years ago and just rip them out and use my own cell balancer, I've been running them for about 7 years now.

Thread on it here,
https://camelot-forum.co.uk/phpBB3/view ... =14&t=1013

[Barge17]

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Is the battery anything like this one"
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yes that's the one but with a different label on the case, and I had the BMS remapped by the eBay guy. This was after recharging a battery pack which had a very low voltage. They are all around 3.9 now.
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However it is the original battery which worked OK with the solax inverter. That's why I am persisting with it.
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Thanks for the other replies as well
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[Tinbum]

from http://www.toggenberg.co.uk/wp/wp-conte ... Manual.pdf, the following screenshot which suggests that the battery is over voltage at 55.3, but how that can be right?

55.3v is not over voltage for that type of cell. The battery cells in your battery are a max of 4.2v and a nominal 3.65v that's 58.8v and 51.1v