WWWS (what would Will Say) EG4 vs SOK server rack battery

[HighTechLab]

SMA Communication Update:
I've finally made progress, but not in the direction I had hoped. Since SMA has been giving us the run around and didn't want to work with us to fix the issue of how the inverter responds to the BMS, we have been forced to make physical changes within the BMS to address the operation issues. A new version was finalized this week and tested overseas and is now en-route to me for final testing. Once I give the final green-light, I am ordering 50 retrofit BMSs and future production will include this updated BMS.

Info regarding the retrofit / customers with existing packs and SMA inverters

• Only the master battery that communicates with the inverter will need to be updated to the new SMA compatible BMS.

Two options existing for customers who want to take advantage of the new BMS

1. We can ship you the retrofit BMS and you can replace it on your own in-field
   • We will make a step-by-step instruction and video tutorial for this.
   • Your warranty is not invalidated by upgrading the BMS on your own.
   • We will cover the cost of the BMS and shipping to you.
   • Please email dexter@currentconnected.com if you wish to be put on the waiting list for the retrofits to arrive.
2. If you were planning on adding another battery to your system, we can replace the BMS in-house prior to shipping, so it's ready to go out of the box.
   • You must make a note in the "order notes" field during checkout otherwise we won't know to make this change!

 

[Hedges]

I understand (from Midnight) that later version Sunny Island firmware changed with regard to communication with Sunny Island Charger. This also broke Midnight's interface to Classic SCC. I've used SIC-40 with SI 5048US, haven't tried with 6048US yet. I've stayed with original firmware in all my SMA equipment.

Lithium support has been in Sunny Island for a while. Can you identify which firmware revisions you know your modified BMS is compatible with?
Any you know it is not compatible with?

 

[robby]

@HighTechLab Part of the deal should be that he old BMS is shipped back to you after the new one is installed.
You cannot have enough Spare BMS's lying around for future repairs.

 

[HighTechLab]

Lithium support has been in Sunny Island for a while. Can you identify which firmware revisions you know your modified BMS is compatible with?
Any you know it is not compatible with?

At this point, we can't say either way with 100% certainty, at least not yet. I'm going to get some of these new BMSs out in the field (and I will collect inverter serial numbers as we distribute them) and if we find any problems we will identify the inverter serial numbers effected if any come up.

Our long-term goal is obviously to have 100% compatibility.

@HighTechLab Part of the deal should be that he old BMS is shipped back to you after the new one is installed.
You cannot have enough Spare BMS's lying around for future repairs.

We discussed this, and I was highly considering it. The thought that made me scratch this idea is, this is a brand new revision to the BMS that just came out. We do not have any real-world testing like we do with the current BMS. While we don't anticipate any catastrophic issues, if the customer does encounter something, they have the old BMS to fall back on to keep their lights on (in voltage-controlled mode). The last thing we ever want is someone being stranded without power and a $100 part (that costs $15 to ship back to us, so really it's only worth $85) is not worth taking away peace of mind.

 

[Hedges]

Our long-term goal is obviously to have 100% compatibility.

Would be great if your firmware, a single version, is compatible with all version of SI firmware, old and new (that include LI BMS support.)

 

[beastman]

At this point, we can't say either way with 100% certainty, at least not yet. I'm going to get some of these new BMSs out in the field (and I will collect inverter serial numbers as we distribute them) and if we find any problems we will identify the inverter serial numbers effected if any come up.

Our long-term goal is obviously to have 100% compatibility.


We discussed this, and I was highly considering it. The thought that made me scratch this idea is, this is a brand new revision to the BMS that just came out. We do not have any real-world testing like we do with the current BMS. While we don't anticipate any catastrophic issues, if the customer does encounter something, they have the old BMS to fall back on to keep their lights on (in voltage-controlled mode). The last thing we ever want is someone being stranded without power and a $100 part (that costs $15 to ship back to us, so really it's only worth $85) is not worth taking away peace of mind.

Dexter, I appreciate your feedback here on the forums. I have an SMA system (SB7000US, SB6000US) and a couple of 5048 sunny islands. I want to purchase 8x of your sk48v100 (41kw) and use this with the 5048 SI inverters. I'm a techie (VP of Engineering) for 16 years at a wireless company and also run an automotive electronics company (atmega328p, canbus, etc) product is what we design and sell. Do you have any input on the SMA can protocol that might help me get your product working?

I would suspect that part of the problem is going to be topping off the battery and subsequent dumps into the system --- on EV's the regen feature only works when the battery is below 85% or so on my Tesla model s, I would be curious if you are dealing with a similar problem when these go into overvoltage protection mode. Either the voltage being read is inaccurate from the ADC due to ESD or other transients or when engaging loads there is not enough headroom. I'm planning to charge my setup to 82% or so max and discharge down to 20%. That really leaves me with about 25kw or so of usable power on a 41kw setup to get the cycles out of these.

If you have any scripts or configuration options I can work with, please let me know. I'm planning to pull the trigger on the batteries before Dec 1.

Thanks

Brock