Batrium SMA Sunny Island Integration issue?

[1201]

The 50 amp is the limit for the shunt reading not the grid so far as I can tell from experimenting this morning. After I got the shunt reading I could change the settings live and it would adjust. That said it is only reading half of the load going into / out of the battery.

The reason it was dumping the full load of the SB into the battery is it didn't see the shunt reading ... which is odd ... you think the default would be to NOT do anything if it can't see the shunt properly when ramping up / down in power. I had previously wired this to bypass that shunt and just used it as a big terminal block to bridge two wires on one post of the shunt.

So I need to rewire these units as the shunt is currently setup to only read off one of the SI's. This will likely mean finding another scrap shunt to use in place of the current one in the master load center so I can use it as a terminal block and migrating the one which came with the MN load center to be in series right at the BMS terminal block, and then shifting the two negative wires over as they currently split at the BMS shunt to each unit.

I didn't realize the shunt could control output. I don't currently have a shunt tied into My sunny islands, or any DC chargers

 

[callmeburton]

I didn't realize the shunt could control output. I don't currently have a shunt tied into My sunny islands, or any DC chargers

Not that you have to but now you have some type of incentive to hook up a shunt :D ... only if you want to experiment that is.

 

[1201]

Not that you have to but now you have some type of incentive to hook up a shunt :D ... only if you want to experiment that is.

Actually I was planning to do so this week. I got a DC charger (victron charge controller) so in have to hook up a shunt. I'm hoping to just use my existing smart shunt. We will see how that goes.

 

[callmeburton]

I use 2.36 (56.6v)for full, equalization and boost, 2.30 (55.2v)for float. You can adjust to your settings

shouldn't this be 3.36 and 3.30 ? I can't see a way to adjust the voltage that high on the SI for VLRA.

 

[1201]

shouldn't this be 3.36 and 3.30 ? I can't see a way to adjust the voltage that high on the SI for VLRA.

Vrla settings are based on 24 cells not 16 so if you use 2.36 is 2.36*24=56.64v

 

[callmeburton]

Vrla settings are based on 24 cells not 16 so if you use 2.36 is 2.36*24=56.64v

just broke out book and saw that lol ... was about to post since I answered my own question.

 

[Hedges]

shouldn't this be 3.36 and 3.30 ? I can't see a way to adjust the voltage that high on the SI for VLRA.

Vrla settings are based on 24 cells not 16 so if you use 2.36 is 2.36*24=56.64v

I always say, don't assume you have to stick with 48V nominal (24s VRLA).
Set up a spreadsheet, see if you can hit the 16s LiFePO4 voltages you want.
I think it is 46V nominal (23s VRLA) that make all desired high and low voltage setpoints possible.

 

[1201]

I always say, don't assume you have to stick with 48V nominal (24s VRLA).
Set up a spreadsheet, see if you can hit the 16s LiFePO4 voltages you want.
I think it is 46V nominal (23s VRLA) that make all desired high and low voltage setpoints possible.

48v is able to hit all the set points no problem. Can set float as low as 2.25 (54v) and boost as low as 2.3v(55.2) which is about perfect for lifepo4

 

[Hedges]

How about low voltage disconnect?

 

[1201]

How about low voltage disconnect?

Afaik it uses calculated soc not voltage. Is there a low voltage disconnect?

 

[Hedges]

Well, if my 100 Ah battery is down to 40 Ah after 12+ years, I'm pretty sure SI shut down due to voltage not SoC calculated from Ah. Or maybe if never tried to change modes, just ran out of juice.

I would think low voltages likely push SoC at low end. But don't know, I don't find any parameters for low end.

 

[1201]

Well, if my 100 Ah battery is down to 40 Ah after 12+ years, I'm pretty sure SI shut down due to voltage not SoC calculated from Ah. Or maybe if never tried to change modes, just ran out of juice.

I would think low voltages likely push SoC at low end. But don't know, I don't find any parameters for low end.

Si also calculates soh so who knows?

 

[callmeburton]

Have had it setup vlra since it was suggested here ... most of the time the battery is hovering in the low 80%'s even after a sunny day ... today, full sun, end voltage 53.0 ... I am using the 2.36 / 2.27 suggested above and even set my "full" frequency to 1 day vs the default 14 as I thought that might "fix" the issue.

 

[1201]

Have had it setup vlra since it was suggested here ... most of the time the battery is hovering in the low 80%'s even after a sunny day ... today, full sun, end voltage 53.0 ... I am using the 2.36 / 2.27 suggested above and even set my "full" frequency to 1 day vs the default 14 as I thought that might "fix" the issue.

Where's the power going?

 

[callmeburton]

Where's the power going?

Obviously not into my battery :/

I start the day around 52.8 and end at 53.0 on average ... we have a small 200w load at night and during the day small peaks of 1.5kw use for a couple minutes then nothing for the day.

This morning I woke up, cycle was on "Full" with 4.5hrs to go, I was making some hot water and using 1.5kw while my 8am sun was giving my batteries 1.2kw ... so the power is "there" but it isn't making its way into the battery :/

I think I need to increase the float voltage or something ... I only have a 280ah battery and I suspect when I build out my second 280 (which is waiting for me in some boxes here) it still overall wont go above 80-85% often :/

 

[1201]

Obviously not into my battery :/

I start the day around 52.8 and end at 53.0 on average ... we have a small 200w load at night and during the day small peaks of 1.5kw use for a couple minutes then nothing for the day.

This morning I woke up, cycle was on "Full" with 4.5hrs to go, I was making some hot water and using 1.5kw while my 8am sun was giving my batteries 1.2kw ... so the power is "there" but it isn't making its way into the battery :/

I think I need to increase the float voltage or something ... I only have a 280ah battery and I suspect when I build out my second 280 (which is waiting for me in some boxes here) it still overall wont go above 80-85% often :/

What pv source do you have?

Do you have the grid connected?

 

[1201]

Additional questions. What do you have battery charge current set to?

How about ac charging current?

 

[callmeburton]

100% offgrid with gen backup set
2x SI set to 60hz "split phase" single cluster
12.5kw of panels into a SMA SUNNY BOY 7.0 which maxes out at 7.5kw 240 AC (though I have only done it twice when running two large power drainers and charging from 30% SOC)
SB is not connected to the SI via COMMs so it uses phase shifting to communicate. (On that note I have seen the SB "turned off" by the SI, if I recall it will throw a local error code on the SB saying something which indicates AC out of range ... this while the battery is still < 95% and the sun is out :/ )
Battery max charging current set to 50ah with the single 280ah battery
InvChrgCurMax 48ah

Battery was 53.0 this morning so likely exaggerated the previous number for morning starting point. It is only 7am so need to wait an hour before power starts to make it to the battery.

 

[1201]

100% offgrid with gen backup set
12.5kw of panels into a SMA SUNNY BOY 7.0 which maxes out at 7.5kw 240 AC (though I have only done it twice when running two large power drainers and charging from 30% SOC)
Battery max charging current set to 50ah with the single 280ah battery
InvChrgCurMax 48ah

Battery was 53.0 this morning so likely exaggerated the previous number for morning starting point. It is only 7am so need to wait an hour before power starts to make it to the battery.

I would bet that the system is throttling your sunny island hard.

50a battery charging current is only about 2.4kw. change that to 300 for now and please let us know what happens

 

[callmeburton]

I would bet that the system is throttling your sunny island hard.

50a battery charging current is only about 2.4kw. change that to 300 for now and please let us know what happens

300 is beyond 1C though? Thought these batteries (since they are all essentially rejects that were not good enough for automotive use) liked .5C max?

Updated details in post above, also 80% SOC (53vdc) should mean only ~60ah is missing ... at 50ah that should mean 1-2 hours of charging depending when the SI decided to throttle back or goto float.

I will keep an eye on states today while working to see when it does what.

 

[1201]

300 is beyond 1C though? Thought these batteries (since they are all essentially rejects that were not good enough for automotive use) liked .5C max?

Updated details in post above, also 80% SOC (53vdc) should mean only ~60ah is missing ... at 50ah that should mean 1-2 hours of charging depending when the SI decided to throttle back or goto float.

I will keep an eye on states today while working to see when it does what.

So set it to 140amps then. 50a is too low.

Do you have a way to measure frequency? A multimeter or something? When the sun is max test your frequency and see if it's higher than 60.00hz

 

[kommando]

I use yasdi2mqtt to extract data from the SI, I monitor the frequency reported and use that to trigger additional loads to reduce throttling of PV output. My current 15kw 48V 280AH Lithium cells have a recommended charge rate for longevity of 0.5P so max charge rate is set to 150A on BMS and the SI. But I have read elsewhere that the SI can overshoot the charge rate by 10% so 135/140A on the SI is better. I am running closed loop with JK BMS set to Pylon/Deye or Goodwe which all work with SI Lithium ext BMS mode.

 

[callmeburton]

Observations now I have had an hour or so of sun.

I set float to 2.3 from 2.27, while in float voltage was 54. Float stopped putting energy into battery though and now at 53.1. I watched it ramp down the amps as the frequency ramped up to 61.5 if I recall correctly. Then the frequency dropped down to 58.9 where it sits now not throwing anything into battery.

It is reporting SOC at 77.6 which is likely pretty accurate ... PV seems to providing the ~200w load we current have going with the lights on.

 

[callmeburton]

Just gave the inverters a 1500w load for 2+ minutes. Battery took 100% of the load and after about 2 minutes the PV took the load and was charging the battery as well. Removed load at 3 minutes and now it is ramping the charging back down. Still indicating float mode. SOC post ramp down is 77.9

So looking at book, the compact meters page. Current set point of charging voltage is 53.7, actual voltage 53.0, active charging process FLOAT
Error SOC is 4.9 ... this with float voltage set to 2.3 which if the math is right should be 55.2vdc

 

[1201]

Observations now I have had an hour or so of sun.

I set float to 2.3 from 2.27, while in float voltage was 54. Float stopped putting energy into battery though and now at 53.1. I watched it ramp down the amps as the frequency ramped up to 61.5 if I recall correctly. Then the frequency dropped down to 58.9 where it sits now not throwing anything into battery.

It is reporting SOC at 77.6 which is likely pretty accurate ... PV seems to providing the ~200w load we current have going with the lights on.

Turn afra enable off.

I think the sunny island will not output power at 58.9hz.

If you turn afra enable off frequency won't go below 60 and you should start charging again