diy solar

diy solar

Sunny island 6048

Reminds me someone reports successful Sunny Island operation with DIY lithium and a particular BMS:

I guess I don't follow, I only see someone saying they use REC-bms. Which yeah, if I had to buy a BMS again definitely a REC. But am I missing a post about another DIY BMS someone made?
 
Olibri,
is your AC coupled PV set up on AC1 (island) or AC2 (grid) side of the SMAs? If it was an existing gridtied system, then probably on AC2? Or you've rewired to put it behind the SMAs on AC1?
Auto mode will let the SMAs connect to grid based on SOC thresholds that you set, and there are two configurable daily time ranges available.
Maybe try first without grid feed enabled? Unless all your solar is on AC1 which will fill up your battery and then you'd need to dump it somewhere.
I just wired AC1 to my main panel and AC2 to the grid, so PV is now on the island side. Yes, I generate way too much electricity for the small battery that I have, so I would prefer to dump to the grid which is why I am configured for GridFeed.

@madsci1016 The BMS is internal and custom from the battery seller. It basically just protects against over/under voltage, overtemp, and provides balancing of the cells. There is no way that I could tie this to the SI. I did it this way because I started with not knowing anything and I needed to start reducing variables and unknowns. One of them was not dealing with a BMS.
Good idea on recommissioning. I hadn't thought of that. TBH when I first tried it I had hot battery wires because I max battery current was set for something like 125A. I learned a lot about current and wire gauges that day... Anyway, I think that I can safely reset everything and try again.
 
I guess I don't follow, I only see someone saying they use REC-bms. Which yeah, if I had to buy a BMS again definitely a REC. But am I missing a post about another DIY BMS someone made?
Not a DIY BMS, rather identifying REC as as BMS you can connect to a DIY lithium battery. So buying that for the $$$ it costs should fix your issue.
Previously, I only saw a list of (expensive) lithium batteries with included BMS that Sunny Island supported.
 
Not a DIY BMS, rather identifying REC as as BMS you can connect to a DIY lithium battery. So buying that for the $$$ it costs should fix your issue.
Previously, I only saw a list of (expensive) lithium batteries with included BMS that Sunny Island supported.

O yeah the only two options for commercial DIY BMS i know of are Batrium and REC, for sure. After the disaster Batrium has been for me and the fact i have LiFEPO4 batteries, I'm trying to go BMS-less at this point, which is why I started looking into hacking the Victron Ecosystem to make my SMA SIs happy in Lithium mode. So far it's been great. I plan to manually check and balance my batteries every few months.
 
Did anyone ever get/find the older SI6048 firmware that didn't need a BMS when selecting lithium profile?
 
Did anyone ever get/find the older SI6048 firmware that didn't need a BMS when selecting lithium profile?

Don't think that ever existed, because these were designed for lead acid only originally, and then rather the invest a whole bunch in R&D for new SoC calculation and safety code for each type of Lithium chemistry, they "enabled" Li-ion by simply playing dumb and expecting an outside device to do all the work for them. Like calculate SoC and implement CC-CV charge controllers, etc.

But could be wrong. I would be very surprised though.
 
the battery selection part was just range of voltages, the first profile called lithium did not need a BMS when that profile came out in a firmware update.
 
We have the same problem we have and SMA inverter and we are trying to set it up with LIfepo4 contacted SMA and they told us that the only way was to set it up as Valve regulated lead-acid battery and change the parameters has anyone done this? or has anyone found a way to set it up as lithium without a communication cable.
 
We have the same problem we have and SMA inverter and we are trying to set it up with LIfepo4 contacted SMA and they told us that the only way was to set it up as Valve regulated lead-acid battery and change the parameters has anyone done this? or has anyone found a way to set it up as lithium without a communication cable.
I used all the different lead acid modes and so has David Poz. We both hated it because you can't get full range of discharge out of your batteries. I found you loose about 15-20% of your battery capacity because the SMA tends to freak out at the low end and re-calibrate SoC to 0% and shut off when it should be 15%.
 
I used all the different lead acid modes and so has David Poz. We both hated it because you can't get full range of discharge out of your batteries. I found you loose about 15-20% of your battery capacity because the SMA tends to freak out at the low end and re-calibrate SoC to 0% and shut off when it should be 15%.
Thanks, I have it set up like this for now too ? I'm a noob at this battery thing can you help me configure the parameters for the battery (I already changed it to Valve regulated lead-acid battery but don't know what else i need to change as far -boost charge V- Full Charging - everything lol Thanks in advance!
 

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Thanks, I have it set up like this for now too ? I'm a noob at this battery thing can you help me configure the parameters for the battery (I already changed it to Valve regulated lead-acid battery but don't know what else i need to change as far -boost charge V- Full Charging - everything lol Thanks in advance!
LivingHakuna, which SunnyIsland inverter(s) do you have, SI6048? Is your screenshot using a Sunny Remote or Webbox, that you're using change settings in the Island inverter from a PC? How is that connected to the inverters? It would be very interesting to figure out what the communication messages are which change settings in the Island(s), adding a can adapter to log messages. Tell us more?

Can you describe your system in more detail? What is your battery bank exactly? 16S? and 340Ah? What are the min and max cell voltages you want to operate between.

Max discharge current, 900A it may not matter, you loads may not pull that anyway, but, is that pretty high?

eq and boost, maybe don't want to do those for lithium, esp eq. so set boost and eq cell volt same as 'full' and float target voltages. turn off auto eq charge. All those voltages should be lower than the safe max voltage, just in case eq or boost gets triggered, at or very close to the upper voltage that you want to go to. (about 3.6v?)

cycle time full charge: this is meant to trigger a charge to 'full' at least every so often, shouldn't need for lithium.

discharge cut-off, 35/16 would be 2.2v, do you want to go that low? maybe 2.5*16 = 40v If the Ahr capacity is reasonably correct, This shouldn't trigger anyway, the amphour integrated SOC should get very low before the voltage drops, since the LFPo voltage stays higher than lead acid which the SMA is assuming. The different SOC based limits in the inverter should already stop discharging or connect to grid by then., maybe.. If if can be kept out of the low SOC recalibration feature somehow. The aux relays could be programmed to trigger some load shedding based on SOC. Or trigger to reconnect to grid.

My system is lead acid with SMA SI6048US inverters, so use a grain of salt.
 
LivingHakuna, which SunnyIsland inverter(s) do you have, SI6048? Is your screenshot using a Sunny Remote or Webbox, that you're using change settings in the Island inverter from a PC? How is that connected to the inverters? It would be very interesting to figure out what the communication messages are which change settings in the Island(s), adding a can adapter to log messages. Tell us more?

Can you describe your system in more detail? What is your battery bank exactly? 16S? and 340Ah? What are the min and max cell voltages you want to operate between.

Max discharge current, 900A it may not matter, you loads may not pull that anyway, but, is that pretty high?

eq and boost, maybe don't want to do those for lithium, esp eq. so set boost and eq cell volt same as 'full' and float target voltages. turn off auto eq charge. All those voltages should be lower than the safe max voltage, just in case eq or boost gets triggered, at or very close to the upper voltage that you want to go to. (about 3.6v?)

cycle time full charge: this is meant to trigger a charge to 'full' at least every so often, shouldn't need for lithium.

discharge cut-off, 35/16 would be 2.2v, do you want to go that low? maybe 2.5*16 = 40v If the Ahr capacity is reasonably correct, This shouldn't trigger anyway, the amphour integrated SOC should get very low before the voltage drops, since the LFPo voltage stays higher than lead acid which the SMA is assuming. The different SOC based limits in the inverter should already stop discharging or connect to grid by then., maybe.. If if can be kept out of the low SOC recalibration feature somehow. The aux relays could be programmed to trigger some load shedding based on SOC. Or trigger to reconnect to grid.

My system is lead acid with SMA SI6048US inverters, so use a grain of salt.
I have a Sunny island 6.0H from Europe and it can be configured so I connected the inverter to my router and I'm able to see all the parameters via my computer. I don't know if it's the same as the US version.

My system is 4 batteries from bigbattery.com 24V 170 ah two and two connected in series and then in parallel creating one big 48V 340ah battery. I have done some research and I think the only way to operate the batteries to 90 -100% with the inverter would be switching the BMS to one that has a can bus communication port.

I don't really know what should the parameters be that is why I posted the picture lol - I know some of you guys use the SMA inverter in Valve regulated lead-acid setting but do I have to change any parameters?
 
The 6H is a very different beast form the 6048s we are talking about here.

If money isn't an object for you I would recommend getting a REC BMS and poping the covers off those batteries to get to the cell wires. Do not consider a Batrium.

Otherwise when I get time I'll try and find my notes for cell value values for lead acid mode. Remember I never was happy with it though.
 
The 6H is a very different beast form the 6048s we are talking about here.

If money isn't an object for you I would recommend getting a REC BMS and poping the covers off those batteries to get to the cell wires. Do not consider a Batrium.

Otherwise when I get time I'll try and find my notes for cell value values for lead acid mode. Remember I never was happy with it though.
I will look into the REC BMS but for now, since I'm in the Bahamas if you can help me with the cell values when you have a chance that would be greatly appreciated. ??
 
TO make sure you understand, those "cell level thresholds" in your screenshots are for a 24 cell lead acid battery. You have a 16 cell LiFEPO4 battery. So it may be easier for you to just talk overall battery thresholds, and then divide by 24 to enter them in those fields.

For example, if i say 56.6V is good for full charge = 56.6 / 24 = 2.35V is what you'd enter into the SMA.

So good values for LiFEPO4:

Full Charge, Boost Charge, Equalization charge = 56.6V (Lithium doesn't need these to be different).
Float Charge = 54.0V.
Time Full, Boost, Equalization = 2 hours. (Lithium doesn't need these to be different).
Cycle Full, Cycle Equalization = set these to their lowest values.

Again I found the SMA still did funny things with SoC with these settings, but they are at least good to charge your batteries at.
 
TO make sure you understand, those "cell level thresholds" in your screenshots are for a 24 cell lead acid battery. You have a 16 cell LiFEPO4 battery. So it may be easier for you to just talk overall battery thresholds, and then divide by 24 to enter them in those fields.

For example, if i say 56.6V is good for full charge = 56.6 / 24 = 2.35V is what you'd enter into the SMA.

So good values for LiFEPO4:

Full Charge, Boost Charge, Equalization charge = 56.6V (Lithium doesn't need these to be different).
Float Charge = 54.0V.
Time Full, Boost, Equalization = 2 hours. (Lithium doesn't need these to be different).
Cycle Full, Cycle Equalization = set these to their lowest values.

Again I found the SMA still did funny things with SoC with these settings, but they are at least good to charge your batteries at.
Thanks, I just updated these parameters. Yes I see that SOC it's a little crazy goes from 50% to 90% when the solar is charging then from 90% to 70% when I turn the solar off lol

Now I have to figure out how set up renogy battery monitor ?.

Thanks for you help I will let you know of any updates!
 
O yeah the only two options for commercial DIY BMS i know of are Batrium and REC, for sure. After the disaster Batrium has been for me and the fact i have LiFEPO4 batteries, I'm trying to go BMS-less at this point, which is why I started looking into hacking the Victron Ecosystem to make my SMA SIs happy in Lithium mode. So far it's been great. I plan to manually check and balance my batteries every few months.
Newbie here. I'm just about to order a bms that has rs485 but batrium says the WM5 (not leafmon - I'm using leaf modules gen2 14s7p) has CANbus of course my 6048's have rs485. Batrium insists I pay for 30min tech line hookup. Well can the WM5 do rs485 or not what the heck? I'm not spending $800 to find out it's a useless brick. Looking at the functionality of the REC now. Annoys me these little controllers are almost $1000. Just ridiculous. I have 2x6kw sunny boy 41series (brand new) ac-coupled to my two 6048's. That's limit on ac-couple (56A relays in the SI's)! I also have 2x7kw sunny boys for straight gridtie only. SMA's documentation leaves a lot to be desired in the details. I wish someone had similar setup to mine and did a video on it. :-/
 
Newbie here. I'm just about to order a bms that has rs485 but batrium says the WM5 (not leafmon - I'm using leaf modules gen2 14s7p) has CANbus of course my 6048's have rs485. Batrium insists I pay for 30min tech line hookup. Well can the WM5 do rs485 or not what the heck? I'm not spending $800 to find out it's a useless brick. Looking at the functionality of the REC now. Annoys me these little controllers are almost $1000. Just ridiculous. I have 2x6kw sunny boy 41series (brand new) ac-coupled to my two 6048's. That's limit on ac-couple (56A relays in the SI's)! I also have 2x7kw sunny boys for straight gridtie only. SMA's documentation leaves a lot to be desired in the details. I wish someone had similar setup to mine and did a video on it. :-/
I think you want a lithium BMS on the CAN bus, not the rs485.

The SI6048US has CAN that the REC, Batrium, or your own BMS can talk to, if the SIs are set to Lithium mode. That is what madsci has hooked up to (read back a little more in this thread, and he has more details here https://github.com/madsci1016/SMAVenusDriver). Also further back in this thread, MurphyGuy has 2xSI6048, + ac coupled SMA sunnyboys, and lithium with REC bms on CAN bus, so that does work also.

If the SIs are in FLA mode, there are different signals on the CAN bus, I'm using lead batteries. I modified a script from python-can to listen on the CAN, label signals and publish to mqtt. Still some more signals to figure out. https://github.com/dalklein/python-can/tree/can2mqtt

There is an rs485 bus also, that needs a piggyback board to connect to, and maybe that will allow changing settings in the SI configuration as well as requesting most any signal there is in there.
 
Another option is the Zeva BMS, works out cheaper than REC or Batrium.
 
I think you want a lithium BMS on the CAN bus, not the rs485.

The SI6048US has CAN that the REC, Batrium, or your own BMS can talk to, if the SIs are set to Lithium mode. That is what madsci has hooked up to (read back a little more in this thread, and he has more details here https://github.com/madsci1016/SMAVenusDriver). Also further back in this thread, MurphyGuy has 2xSI6048, + ac coupled SMA sunnyboys, and lithium with REC bms on CAN bus, so that does work also.

If the SIs are in FLA mode, there are different signals on the CAN bus, I'm using lead batteries. I modified a script from python-can to listen on the CAN, label signals and publish to mqtt. Still some more signals to figure out. https://github.com/dalklein/python-can/tree/can2mqtt

There is an rs485 bus also, that needs a piggyback board to connect to, and maybe that will allow changing settings in the SI configuration as well as requesting most any signal there is in there.
Hang on, the SI6048's have CANbus? News to me. I understood you need the rs485 piggyback card to get the inverter to communicate at all. Hmm. I did have an email from Ian @ ZEVA and he says "Unfortunately our BMSs don’t have an RS485 interface and only support CAN bus, so if your inverters only support RS485 then the BMS wouldn’t be able to communicate digitally." I have seen rs232/rs485 to CANbus bidirectional converters out there but approaching $150+ and of course no idea if it'll work. I'll check the other threads. From what I can tell both are serial bus protocols but the "language" if you can call it that is different for both.
The https://www.orionbms.com/products/orion-jr2-bms/ is also very interesting, but again only CANbus.
Here's a bidirectional serial bus converter, check it out how the rs232/485 differs from CANbus:
Who sells REC hardware as they don't sell off their website?
 
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