Hi

Does anyone have experience with the SunSynk Rack mount HV battery? (12 x 5.1kWh modules in series)
My two main questions are:

1) Can it function like other suppliers' HV batteries in the sense that you can "build your own" battery by combining a custom amount of 51.2V modules in series to reach your desired kWh (Obviously staying within your inverter's Battery voltage range) Atess and BlueNova are some examples.

2) Assuming one wishes to make use of SunSynk's 10yr warranty by pairing a SunSynk 50kW with this HV battery: The SunSynk 50kW is IP65 rated. By installing these battery modules in a custom IP65 server rack, would that void the warranty of the battery? ie are you forced to use their "server rack"

3) Assuming "1)" is true and the modules can be expanded, what is the max amount of modules one can add in the "battery string" from a CAN-Bus communications perspective? 

FYI I see SunSynk has an 80kWh (665V)version available lately, which correlates to them using 120Ah cells in a "13-pack" configuration indicating that the battery is NOT fixed to 12 modules as with the 61kWh version.

Herholdts is struggling to find the technical in-house expertise to answer my question, and SunSynk has not replied to my email from 2 days ago...

Bump

 

Bump

Hi @Multiwatt

Firstly what kWh level are you trying to reach? Secondly what Voltage are you trying to reach ? There are other battery options & other inverter options that make your requirement possible...ATESS & FreedomWon.

Sunsynk will not answer your question neither will Herholdts. Sunsynk are not the OEM so they a middle man, Herholdts are also a middle man. Trying to communicate with 2 middle men is difficult. Deye are the OEM communicate directly with them, they know the product well, as they produced it. 

Unfortunately, these guys want to play in the HV market with commercial power. But Commercial power needs proven concept & engineering, you simply cannot do this on a fly & you need good amount of R & D before you roll out. Unfortunately, from what I have seen these guys are still thinking in the residential market. They think they can release a product that they can solve with firmware once it's out in the wild. 

A very good way to burn your fingers in the Commercial market!!

Edited March 4, 20242 yr by Steve87

Hi @Multiwatt

I hope you don't mind me asking, but what do you plan on powering with this system?

HV is mainly there for the commercial/Industrial/agricultural sector and most of these businesses tend to power huge water pumps,CNC machines, injection moulding etc, which would lend themselves more to LF inverters given the system is specced correctly.The HF inverters like Sunsynk for example would generally struggle with these inductive loads (especially if several of these need to be stopped and started one after the other) as you won't get the same flywheel effect one would get from the transformer based (LF) inverters like Victron (some installers like using several of the 15kva Quattros) and the likes of Atess, where they predominantly focus their product around the commercial sector.

I agree with @Steve87 ,in that R&D is mostly based on feedback.And if your feedback comes mostly from residential installations where your product makes more sense, then that is where you most likely going to make the largest progress in terms of rolling out new features or even a new product.Without gradually going up in the weight class and taking on the commercial sector starting off on a fresh piece of blank paper, then Sunsynk would be like a lightweight boxer getting into a ring with Mike Tyson in the heavy weight division...one would be asking for a knockout lol.

Afternoon Gentlemen

Thanks for the replies.

Let me give you a bit of background: The reason I'm asking about the SunSynk HV batteries is to quote on a 3ph system for a school with a peak load of about 40kW. Since the school is comprised of mainly Capacitive and unity-PF loads (LED's, Computer PSU's, Geysers etc) I figured I would like to suggest a system with their financial constraints in mind. I too am a fan of Low Freq transformer based solutions, but in this instance I took the calculated risk of proposing a 50kW 3ph high voltage SunSynk for their needs. The problem as i'm sure you know is that SS only supply their 10yr warranty if one uses their "approved battery brands" with the inverter. Pointless if you ask me since they all use CATL or BYD cells if they are half decent. Nevertheless.

The major advantage of the HV "string" battery approach (ie a rack comprised of 51.2V modules in a series "string) is that the client can expand in smaller increments should the need arise. They don't have to lay down the cash of another Freedom Won 80/64 in parallel. An engineer can design the system to initially be within the lower DC bounds of the battery voltage and they can expand in 5kWh (or 6.3 or 10kWh bla bla bla) "steps" by adding one or two in series up to the upper DC bound of the inverter.

Before I give my example I would like to explain my self-made-up terminology:
 module is a "pack" of 16 (3.2V) cells in series (the image above has 12 "packs"
A "bank" is a large server rack frame filled with a bunch of "packs" in series and protected by a BMU HV interrupt device.

Example: The SunSynk 50kWh has a Batt DC range of 450V - 850V.
 A 3.2V (nominal) LiFePo4 cell typically has a "depleted" voltage of 3V and a "Charged" voltage of 3.46 (conservatively speaking)
Assuming a "pack" is comprised of 16 cells, that means the SunSynk typically has a limit of 10 modules in series on the lower bound, and 15modules in series on the upper bound. Assuming they are comprised of 100Ah cells that gives an expandability range of 25kWh before one has to split the bank again. 
ie The client can initially invest in a 50kWh "bank" (10 packs) and upgrade in relatively cheap 5kWh steps all the way to 75kWh. Whereafter one can take the leap, buy 5 more units and build two "banks" with the 20 units, and the cycle continues (only now in 2x5kWh steps)

This is dependent on three things:

1) SunSynk allows one to buy the "packs", BMU and frame separately (whilst retaining the 10yr warranty)... >doubt
2) The BMU can interrupt the max DC voltage of 768V safely and reputably

3) The communications in the "bank" can handle this (bonus if you don't have to mess around with DIP switches)

These HV systems will become more prevalent in commercial and Agri scale applications since the "installation-friendliness" of the HV "server rack" architecture is just nicer to work with.

And whilst the Victron HS19 HV inverter is still in the lab, SunSynk can fill the waiting gap

Edit: The 4 x MPPT trackers of the SunSynk 50kW is also a major bonus above the ATESS HPS50's Single tracker. 
Edit 2: The IP65 rating of the SunSynk is also nice

Edited March 4, 20242 yr by Multiwatt

Your case study makes for a compelling decision towards the Sunsynk. Their product is unfortunately more of a paper weight in comparison to the Atess. They have gone on Residential philosophy & ddnt build a clean new design. 

If you are steered to the product id rather choose Deye as they actually know the product well & will give you the best answers. Sunsynk are a rebadger. They ask Deye engineers then revert. 

Yes the Atess has a single MPPT but it can AC couple to a Grid tied inverter & that assures you more MPPTs & it can create a micro Grid. Sounds like the product you really want is the Victron. Why waste on a stepping stone...Just wait or get 3 or 4 x 16kW Deye or Sunsynk machines, they are proven in the residential market & a stable product. That's where Deye & Sunsynk have made their name. Not on the HV model. There is a good reason they now refuting FreedomWon batteries on the HV range. They have made some fundamental mistakes in the design. 

the problem with AC coupling the Atess is that one then requires the Atess bypass cabinet which makes the project more expensive.

I will get the Deye should the client opt for that option.

You do not need the Bypass cabinet at all. That requirement is for the PCS models & that is a requirement for all PCS machines, the inverter cannot function without it. The HPS can AC couple directly. However, a Meter & CTs are required to limit export. The Grid tied inverter connects to the HPS AC output. 

The challenge in the above lies in that sentence "after the grid connected inverter matches the communications protocol of the HPS"
Easier said than done. Atess calls it "running in EMS mode whereby the grid-tie inverter is connected to the Atess via RS485.

It just does not work very nicely. Can't wait for Atess to get a working 3rd party Energy meter provider which one can then connect right below the grid tie inverter and program it as a "PV Inverter energy meter" like the Victron+Gavazzi systems.

SynSynk also fails with this one. Claiming it is "easier" to connect the grid tie straight to the Gen input of the SunSynk which is often very far away.

Typical chinese approach where they churn out what the Europeans have refined, and wait for feedback from the market acting as their guinea pigs.