Sunny Island SI5048 - disable battery management- driving me crazy
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Hedges
I See Electromagnetic Fields!
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How many kW of PV and Sunny Boy do you have?
I have 2 SB 1x 3000TL-20 (with 2.8kw panels) & 1x5000TL-20 (with 2.5kw panels)
I have the battery charging amps set at 190ah (from memory the SI recommended 210ah when I did the setup . but i lowered it to 190ah ) but in reality the maximum charging current my panels will generate will not exceed 115 ah (5500w/48v = 115ah) which makes it around 0.3C of the 400ah battery capacity
How many kWh of battery? (400 Ah) Correct
2.8kW + 2.8kW + 2.5kW panels = 8.1kW available in the best of times.
400 Ah x 48V = 19.200 kWh
8.1 kW/19.2 = 0.42C (reduced for higher battery voltage an typical PV production.)
Or 0.3C you observe.
Try shutting off PV to get lower charge rate. SI is supposed to manage charge current, but when a load disconnects the available PV suddenly has to go into battery.
Does BMS report what it disconnected for? Maybe a cell that was a runner? It doesn't disconnect completely
on my BMS monitoring app I have notices that at full charge that I have a difference of 0.3v in the lifepo4 cells voltage, so one cell would be 3.7v and another 3.4v , and it takes a while before the balancer is able to equalize the voltage down to a difference of 0.03v .
please note that the bms only disconnects the charging but keeps the discharging open (like a diode allowing current to go in one direction only).
What is BMS disconnect voltage? 3.7V sounds high enough to disconnect. Were the cells ever better balanced?
After determining that the system isn't running past full charge due to SB control issues, try reducing charging voltage in SA so highest cell stops at 3.6V. Then after long enough operation that balancing raises lowest cells and drops that one below 3.6V, crank voltage up a little and repeat.
Did you build and top-balance the battery? Or buy it?
If you built and balanced, was it balanced to higher than SI's voltage setting? If not, could manually bleed off charge from higher cells to bring closer to balance. Reduced wattage of SB connected, and switching AC loads, you may be able to reduce charge current for such balancing.
From memory it was still default at 120min
That would seem plenty (if it is actually occurring; frequent disconnect due to running over-voltage might prevent.)
I am not sure if I can control these in my SB as I purchased these second-hand, one of them I can access the settings on it, the other one is locked with a password that I wasn't able to get) and both the SB were used in a grid tie connection. my setup is an offgrid one
Register on SMA website and request PUK Personal Unlocking Key to reset password. It actually isn't personal, it is for that serial number. I label inside of inverter cover with the PUK.
You likely need Grid Guard Code to change some parameters, probably including UL-1741 (or equivalent) changed to island. That is reserved for suitably qualified individuals. One forum member, after showing a letter from utility indicating he was supposed to enable Rule-21, was given access. Some of us had no difficulty getting it, due to our training/work/credentials. In your case, at least say you are installing Sunny Island backup for an existing on-grid system.
I am not sure , Is there a way I can check if this setting is activated?
If you can connect and read settings, you'll see if it is supposed to be.
If you have a DMM with "Hz" scale, it will show frequency of AC line and respond fast enough you can watch frequency while either observing SB disconnect (or not) by relay, or monitoring AC or DC current with a clamp ammeter. Connect one inverter at a time so power from others doesn't affect the test.
What model SB? Some don't do frequency-watts as intended. have 2 SB 1x 3000TL-20 (with 2.8kw panels) & 1x5000TL-20 (with 2.5kw panels)
My original SB 2500SWR, with the ROMs they had, didn't support this. I bought 10000TL-US-12 which was on the compatibility list, but found it would only do frequency-watts in Island mode not Backup mode. After I informed SMA, they reviewed firmware, confirmed my observation, changed list to say "backup" was not supported only "island". They (SMA America) told me to use "island" mode for grid-backup installation, which relies on SI for anti-islanding and disconnect. But I didn't have 100% confidence that was 100% safe so I changed models.
Here's the latest compatibility list for the Americas; see if you can find a list for yours.
I have not figured out why our SB 3000TL-US-22 model is supported for backup but NOT for off-grid! I've acquired one but not played with it enough. Seems to me that if configured for backup, it will support off-grid. Maybe that requires RS-485; if so, it may come factory set to support backup and just needs daughter card. "Not supported [for backup] since 2016" - maybe firmware changed then, maybe an existing bug was identified.
I have 2 SB 1x 3000TL-20 (with 2.8kw panels) & 1x5000TL-20 (with 2.5kw panels)
I have the battery charging amps set at 190ah (from memory the SI recommended 210ah when I did the setup . but i lowered it to 190ah ) but in reality the maximum charging current my panels will generate will not exceed 115 ah (5500w/48v = 115ah) which makes it around 0.3C of the 400ah battery capacity
How many kWh of battery? (400 Ah) Correct
2.8kW + 2.8kW + 2.5kW panels = 8.1kW available in the best of times.
400 Ah x 48V = 19.200 kWh
8.1 kW/19.2 = 0.42C (reduced for higher battery voltage an typical PV production.)
Or 0.3C you observe.
Try shutting off PV to get lower charge rate. SI is supposed to manage charge current, but when a load disconnects the available PV suddenly has to go into battery.
Does BMS report what it disconnected for? Maybe a cell that was a runner? It doesn't disconnect completely
on my BMS monitoring app I have notices that at full charge that I have a difference of 0.3v in the lifepo4 cells voltage, so one cell would be 3.7v and another 3.4v , and it takes a while before the balancer is able to equalize the voltage down to a difference of 0.03v .
please note that the bms only disconnects the charging but keeps the discharging open (like a diode allowing current to go in one direction only).
What is BMS disconnect voltage? 3.7V sounds high enough to disconnect. Were the cells ever better balanced?
After determining that the system isn't running past full charge due to SB control issues, try reducing charging voltage in SA so highest cell stops at 3.6V. Then after long enough operation that balancing raises lowest cells and drops that one below 3.6V, crank voltage up a little and repeat.
Did you build and top-balance the battery? Or buy it?
If you built and balanced, was it balanced to higher than SI's voltage setting? If not, could manually bleed off charge from higher cells to bring closer to balance. Reduced wattage of SB connected, and switching AC loads, you may be able to reduce charge current for such balancing.
From memory it was still default at 120min
That would seem plenty (if it is actually occurring; frequent disconnect due to running over-voltage might prevent.)
I am not sure if I can control these in my SB as I purchased these second-hand, one of them I can access the settings on it, the other one is locked with a password that I wasn't able to get) and both the SB were used in a grid tie connection. my setup is an offgrid one
Register on SMA website and request PUK Personal Unlocking Key to reset password. It actually isn't personal, it is for that serial number. I label inside of inverter cover with the PUK.
You likely need Grid Guard Code to change some parameters, probably including UL-1741 (or equivalent) changed to island. That is reserved for suitably qualified individuals. One forum member, after showing a letter from utility indicating he was supposed to enable Rule-21, was given access. Some of us had no difficulty getting it, due to our training/work/credentials. In your case, at least say you are installing Sunny Island backup for an existing on-grid system.
I am not sure , Is there a way I can check if this setting is activated?
If you can connect and read settings, you'll see if it is supposed to be.
If you have a DMM with "Hz" scale, it will show frequency of AC line and respond fast enough you can watch frequency while either observing SB disconnect (or not) by relay, or monitoring AC or DC current with a clamp ammeter. Connect one inverter at a time so power from others doesn't affect the test.
What model SB? Some don't do frequency-watts as intended. have 2 SB 1x 3000TL-20 (with 2.8kw panels) & 1x5000TL-20 (with 2.5kw panels)
My original SB 2500SWR, with the ROMs they had, didn't support this. I bought 10000TL-US-12 which was on the compatibility list, but found it would only do frequency-watts in Island mode not Backup mode. After I informed SMA, they reviewed firmware, confirmed my observation, changed list to say "backup" was not supported only "island". They (SMA America) told me to use "island" mode for grid-backup installation, which relies on SI for anti-islanding and disconnect. But I didn't have 100% confidence that was 100% safe so I changed models.
Here's the latest compatibility list for the Americas; see if you can find a list for yours.
I have not figured out why our SB 3000TL-US-22 model is supported for backup but NOT for off-grid! I've acquired one but not played with it enough. Seems to me that if configured for backup, it will support off-grid. Maybe that requires RS-485; if so, it may come factory set to support backup and just needs daughter card. "Not supported [for backup] since 2016" - maybe firmware changed then, maybe an existing bug was identified.
jdaley
New Member
I have the same problem but dont know what I am doing, in Bendigo there is nobody that understands SMA, I found this which at least mentions LiIon batteries https://files.sma.de/downloads/Off-Grid-IS-en-33W.pdf
Hedges
I See Electromagnetic Fields!
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If this is the inverter you have:
www.sma-australia.com.au
Here's the list of supported batteries:
If DIY batteries, I don't know which BMS works with that model. Maybe someone can tell us.
SMA Sunny Island: The all-purpose solution | SMA Australia
Discover now the most reliable all-purpose solution: the SMA Sunny Island ► easy, proven technology, affordable and communicative in all areas
Here's the list of supported batteries:
If DIY batteries, I don't know which BMS works with that model. Maybe someone can tell us.
jdaley
New Member
Would this be the information needed for the battery type parameters for Lithuim Iron https://www.canbat.com/how-to-charg...=In order to fully charge,t charge it to 100%.
Hedges
I See Electromagnetic Fields!
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That is specific to some lithium batteries with open-loop charging (no BMS communication.)
If you use Sunny Island with a lithium battery that doesn't have compatible BMS, you would configure Sunny Island for AGM and use similar numbers from your battery's data sheet.
Sunny Island nominally uses 48V lead-acid battery (24 cells), and LiFePO4 48V is 16 cells. Sunny Island is configured per lead-acid cell for voltages, so you calculate what lithium battery cell voltage times 16 cells (or what 48V lithium battery voltage), divide by 24, and enter that as lead-acid AGM cell voltages in Sunny Island.
I think no max/min AGM voltages times 24 will match what you want for LiFePO4. I think it was 46V nominal battery, 23 cells, that could be configured in Sunny Island to make LiFePO4 happy.
It is preferable to have a BMS that communicates, but some guys use AGM settings. Likely, state of charge based functions will be offset due to different voltage curves for these batteries.
If you have any DC coupled loads or chargers wired directly to the battery, you should use a battery shunt so Sunny Island knows how much current. It only measures its own current.
If you use Sunny Island with a lithium battery that doesn't have compatible BMS, you would configure Sunny Island for AGM and use similar numbers from your battery's data sheet.
Sunny Island nominally uses 48V lead-acid battery (24 cells), and LiFePO4 48V is 16 cells. Sunny Island is configured per lead-acid cell for voltages, so you calculate what lithium battery cell voltage times 16 cells (or what 48V lithium battery voltage), divide by 24, and enter that as lead-acid AGM cell voltages in Sunny Island.
I think no max/min AGM voltages times 24 will match what you want for LiFePO4. I think it was 46V nominal battery, 23 cells, that could be configured in Sunny Island to make LiFePO4 happy.
It is preferable to have a BMS that communicates, but some guys use AGM settings. Likely, state of charge based functions will be offset due to different voltage curves for these batteries.
If you have any DC coupled loads or chargers wired directly to the battery, you should use a battery shunt so Sunny Island knows how much current. It only measures its own current.
HamzaH
New Member
Hi Hedges,
Thank you for your replies and time!!
I have monitored my system over the weekend and also reduced the charging current of my SI to 65amp and the cell voltage to 2.40 (making it total 55.2V total (meaning 3.45v / LIFEPO4 call) . I have also monitored that when fully charged the frequency changes to around 54Hz which shuts down the sunny boys. everything worked fine for 1 days and the next day I got the SI disconnected and the stored faults were w210 and F201 . which means that the battery is overvoltage. I am not sure how this happened .
do you have any clues or advice to fix this ?
do you think I should use the AGM battery settings instead of the VRLA ? would that make a difference ?
what I think have happened is that when the battery was balancing (I have an active balancer (not resistive) with my system that equalizes the voltage between cells) the voltage differed slightly (maybe became slightly higher and that triggered the overvoltage ?!!
do you have any advise about what voltage to put in boost mode , absorption mode, equalization mode & float mode?
should the voltage be the same for the charging of the cells in all phases ? for example 2.40v in all stages ? or should I start having 2.4v in boost mode and rise that a little (maybe 2.43v) in absorption and equalization and lower it back to 2.4 in float ?
please note that I have the SI5048 model
thank you for your help
much appreciated .
Hedges
I See Electromagnetic Fields!
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I think 5048US and 6048US are identical except for battery cable lugs and efficiency/cooling.
VRLA is the setting for AGM or Gel.
I find those warning and fault codes, but I don't see "overvoltage" thresholds in parameters. (Some bench supplies I use has programmed voltage settings and overvoltage shutdown settings.
You typically don't want "equalization" for AGM or lithium. It is used for FLA and is higher than normal voltage, to overcharge some cells in order to bring lower ones up.
I think LiFePO4 people usually charge to a voltage, then drop to float. Some of the other forum member have probably shared their settings, and the forum resources probably include charge voltages.
Maybe that is possible, the active balancer pulls a little from whole pack (or inverter/charger) and boosts one cell. But I would only expect doing that to highest cell would raise pack voltage, not a cell that needed more charge.
This may be the key. It would normally hover between 51 and 52 Hz to ramp down power from 100% to 0%.
If yours are hitting 54 Hz, apparently SB just cycles on and off.
Do you not observe power ramping down, and frequency hovering somewhere slightly elevated?
Find a way to enable frequency-watts. SB can do that in off-grid mode. Most SB with RS-485 can do that in backup mode when signaled by SI. Newer SB have frequency-watts, which we in the US enable with California's Rule-21. You should have similar.
VRLA is the setting for AGM or Gel.
I find those warning and fault codes, but I don't see "overvoltage" thresholds in parameters. (Some bench supplies I use has programmed voltage settings and overvoltage shutdown settings.
You typically don't want "equalization" for AGM or lithium. It is used for FLA and is higher than normal voltage, to overcharge some cells in order to bring lower ones up.
I think LiFePO4 people usually charge to a voltage, then drop to float. Some of the other forum member have probably shared their settings, and the forum resources probably include charge voltages.
Maybe that is possible, the active balancer pulls a little from whole pack (or inverter/charger) and boosts one cell. But I would only expect doing that to highest cell would raise pack voltage, not a cell that needed more charge.
This may be the key. It would normally hover between 51 and 52 Hz to ramp down power from 100% to 0%.
If yours are hitting 54 Hz, apparently SB just cycles on and off.
Do you not observe power ramping down, and frequency hovering somewhere slightly elevated?
Find a way to enable frequency-watts. SB can do that in off-grid mode. Most SB with RS-485 can do that in backup mode when signaled by SI. Newer SB have frequency-watts, which we in the US enable with California's Rule-21. You should have similar.
I run a SI5048 Euro model on an old set of lead acids, will need to change to Lithium at some point in the next couple of years.
Reading the first post in this thread it says you can run the latest SI6048US firmware on a non US SI5048 gaining access to a Lithium setting and canbus comms to a Pylontech battery.
Being cautious then running ahead to try this based on one post would be IMHO be rash, so I would want a safe exit route if it went bad.
Page 85 of this Training PDF refers to downgrading of firmware being possible manually.
https://www.energistar.com/documentation/Doc_PRESENTATION- SUNNY ISLAND 5048U_20081216160855.pdf
But does not detail how this is achieved.
Until I can find this downgrading info as I only have one SI5048 I will not attempt it, will keep on looking.
On the throttling of the SB inverters then when set to off grid they do reduce their output as the SI increases the frequency from 50 htz to 51.5 htz and above, then late in the day as the sun reaches the horizon the frequency drops below 50htz to take in the lower SB output and to compensate for frequency linked clocks being sent the wrong frequency earlier in the day. I can see this happening on Sunny Data Control.
Reading the first post in this thread it says you can run the latest SI6048US firmware on a non US SI5048 gaining access to a Lithium setting and canbus comms to a Pylontech battery.
Being cautious then running ahead to try this based on one post would be IMHO be rash, so I would want a safe exit route if it went bad.
Page 85 of this Training PDF refers to downgrading of firmware being possible manually.
https://www.energistar.com/documentation/Doc_PRESENTATION- SUNNY ISLAND 5048U_20081216160855.pdf
But does not detail how this is achieved.
Until I can find this downgrading info as I only have one SI5048 I will not attempt it, will keep on looking.
On the throttling of the SB inverters then when set to off grid they do reduce their output as the SI increases the frequency from 50 htz to 51.5 htz and above, then late in the day as the sun reaches the horizon the frequency drops below 50htz to take in the lower SB output and to compensate for frequency linked clocks being sent the wrong frequency earlier in the day. I can see this happening on Sunny Data Control.
Last edited:
Update:
I got a second SI5048 non US and could do some experimentation.
I loaded up the latest SI6048-US firmware 7304-7300 and it was taken and the option for Li-ion ext BMS became available. 50Htz and 230V operation is unaffected.
I then went looking for info on the SMA Canbus protocol for reference when selecting a BMS for a planned DIY Lithium battery and came across this post on a German PV website with an active SMA dedicated section
www.photovoltaikforum.com
Yippeeeee! Yes: It works with ext. BMS!!!!
Dear operators of SI5048 and SBU5000, I learned amazing things about SMA support :
After I complained that the all-important CAN communication regarding battery sizes (even though it follows the official SMA protocol) wouldn't work with my SBU5000 with FW7.210, the following advice came:
I tried it last night. Worked perfectly straight away.
So SMA know it works and at least once told a user it would work, plus my own trial confirms it works on an SI5048 non US (well not got a battery yet to test but no normal functionality has been lost).
I got a second SI5048 non US and could do some experimentation.
I loaded up the latest SI6048-US firmware 7304-7300 and it was taken and the option for Li-ion ext BMS became available. 50Htz and 230V operation is unaffected.
I then went looking for info on the SMA Canbus protocol for reference when selecting a BMS for a planned DIY Lithium battery and came across this post on a German PV website with an active SMA dedicated section
Off-grid in Afrika: Lässt sich der (ältere) Sunny Island 5048 auch mit LiFePO4-Batterien betreiben? - Photovoltaikforum
Ich möchte einen Sunny Island 5048 an einer LiFePO4-Batterie (48V, 100 Ah) betreiben, als Inselanlage zusammen mit PV-WEchselrichtern. (Das wäre für ältere Anlagen, die z.B. in Afrika stehen und bisher mit Bleibatterien betrieben werden, eine gute Art…
www.photovoltaikforum.com
Yippeeeee! Yes: It works with ext. BMS!!!!
Dear operators of SI5048 and SBU5000, I learned amazing things about SMA support :
After I complained that the all-important CAN communication regarding battery sizes (even though it follows the official SMA protocol) wouldn't work with my SBU5000 with FW7.210, the following advice came:
Since this is the US firmware, I was skeptical at first. Especially for operation in the SBU5000 with AS-Box. That's why I confirmed this again:
I tried it last night. Worked perfectly straight away.
- Batt-SoC and temperature are transferred cleanly from the BMS to the SBU5000. This should also work with the Si5048.
- Switchbox control and diagnostics run normally and unobtrusively (for me an M).
- Backup meter box is read in. Power control to increase self-consumption works.
- No: I don't have 60 Hz AC now
- I haven't tested backup power operation yet.
So SMA know it works and at least once told a user it would work, plus my own trial confirms it works on an SI5048 non US (well not got a battery yet to test but no normal functionality has been lost).
