callmeburton
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Yeah the comm's is a must for SMA with any LFP batteries :/ ... it is pretty though.
Batrium SMA Sunny Island Integration issue?
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How so?
callmeburton
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without comms going to the SMA from a BMS hooked up to the LFP the SMA SI will not run :/ let alone charge when asked to. The whole unit will turn itself off right now and restart when the comms drops for a second (one of the current issues with the batrium I have)
SilverbackMP
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My REC setup does that too. Not that often though. Maybe once every two weeks on average. Although that’s an average. Might happen twice a week or go a month without doing it.
You can use vrla settings with lfp. I've been doing that since December and haven't had a single issue.
Now. I do know that the soc will drift from what a smart shunt says and it often reads higher than what the smart shunt says since I rarely go below 35% soc I've never had any issues
That's not good enough. I recommended it before and I'll do it again- consider just using voltage. You have a generator. Set it up so the generator comes on a at say 30% soc and you should not have any issues
callmeburton
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Do you have a link to a thread with your current settings? I assume your doing LiFePo4 in 16s and some number of those in parallel ...
And I assume the SI would have no clue, open loop, that a individual battery is beyond its limits and not know when to stop charging?
I use 2.36 (56.6v)for full, equalization and boost, 2.30 (55.2v)for float. You can adjust to your settings
My bms (jk) does not require communication to do it's job. Does yours?
callmeburton
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My BMS just monitors the cells and makes calls for charging or takes action when certain conditions are met. Shouldn't need coms to do that.
But I know if I throw more than 30 amps into my battery my cells will spike and the BMS normally would call to halt charging to protect against over voltage of an individual cell. With COMMS it is able to do this but I suspect the SI wouldn't be listening to the BMS COMMS if it is set to VRLA?
I will break out the book and flip through the settings for VRLA and maybe run a test ... the BMS will simply disconnect the SI's if things get really bad but I prefer that not be the case.
EDIT: I should add ... the batrium doesn't bleed excess voltage off cells as easily as the REC does ... it really is not designed for LFP :/
What size is your battery? 30a is very little.
callmeburton
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280ah, all eve cells, when one spikes above 2.65 if I recall correctly the BMS disables charging. 30amps is the setting, the SI will spike it up to like 50 for a moment or two before ramping down to 30. If I had it set to 50 it would ramp to 70ish ... the ramping when it first starts charging causes cells to spike as well ... I have a thread about it somewhere if not in this thread.
I won't pretend I know how your bms works but 30 amps at 50v is about what-.1c ? There shouldn't be spiking going on. The closed loop comms is causing trouble. Try Switching to open loop, set the sunny island to 3.45v or somewhere differently below your 3.65v threshold on your bms then you wouldn't have issues
callmeburton
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AGAIN! ... 0430 today it looks like the power shut off ... I came in and the BMS again had reset itself to a default state, the battery voltage was about 30% SOC this time.
I reset it all, and reset the SOC the configured the SI for VRLA and started things up to find the SI dumping 6000w into the battery though I set it to only do 50 amps 0__0 ... I turned it all off and figured it out ... I had bypassed the shunt the SI was reading its current from and I guess it just thought "give it all I got" ... I am sure total I was peaking the output of my SB lol
Will let this go a bit and see what happens.
I reset it all, and reset the SOC the configured the SI for VRLA and started things up to find the SI dumping 6000w into the battery though I set it to only do 50 amps 0__0 ... I turned it all off and figured it out ... I had bypassed the shunt the SI was reading its current from and I guess it just thought "give it all I got" ... I am sure total I was peaking the output of my SB lol
Will let this go a bit and see what happens.
If you set a new battery in sunny island it tries to charge it to full immediately .
If the 50a number is from the grid that would be at 120v nominal and would explain the 6000w
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callmeburton
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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.
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.
My master SI5048 EU is connected to a shunt on a final common line to the battery so it sees its own charging, the slave SI and the supplementary charger and any outflows back the the SI's. I can see the flows in real time as reported by the SI and they match what I expect.
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
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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
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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
