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Battery problem?


VinceG

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Hi all,

I have a 5kw Sunsynk inverter and 2 X 5.32 Sunsynk batteries,

We had load shedding and my batteries where at 70% so 70% - 20% (shutoff) i had 50% usable charge left and if its a 10KWH battery (2 X 5) it should have 5KWh capacity,

So what happened here? 

They only discharged 2.6KWH and then where flat?

Are these brand new battery's faulty or am i missing something?

How can i test?

image.png.8fa1d4fdfca3a464f7654766ccf99b09.png

image.png.e163167b5a84282f4805b8a085ac708d.png

 

Thanks

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On 2023/06/14 at 1:45 AM, VinceG said:

Full graph if required,

Really love my system would hate if something is faulty,

image.thumb.png.402ad0a0310d561d70be40febc41ca65.png

Please post a chart with Battery Voltage, Battery Current and SOC. Please also post a chart where it goes all the way to fully charged. Try and take a reading as well of the max voltage the battery reaches close to the end of charging.

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On 2023/06/21 at 6:40 PM, HendrikBigChief said:

Please post a chart with Battery Voltage, Battery Current and SOC. Please also post a chart where it goes all the way to fully charged. Try and take a reading as well of the max voltage the battery reaches close to the end of charging.

Hi Hendrik,

 

Thanks have a look below:

image.thumb.png.04aa21d282e64ab77edc28c0fd31f25c.png

 

image.thumb.png.5268a099ce2505ae015da7d6980baf5a.png

image.thumb.png.8a77096940c2f1ff7ab546ea74021e5b.png

image.thumb.png.29444f72d94014992ad9f6f0305606d9.png

 

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6 hours ago, VinceG said:

Hi Hendrik,

 

Thanks have a look below:

image.thumb.png.04aa21d282e64ab77edc28c0fd31f25c.png

 

image.thumb.png.5268a099ce2505ae015da7d6980baf5a.png

image.thumb.png.8a77096940c2f1ff7ab546ea74021e5b.png

image.thumb.png.29444f72d94014992ad9f6f0305606d9.png

 

Thanks for the charts.

Your charge cycle to 100% looks good, float voltage also good. Just after the "crash", your voltage is 52.2 with low current of 0.7A,

image.png.7c332464b4aa1ce85cfa799d4af1ca63.png

Using lifepo4 charts, we can determine the rough SOC using the voltage:

image.png.d5893b9bb5ba4b1eddf586e0a2942d16.png

So I would say your actual SOC should be around 50% at that point, not the 15% reported. There is definitely an issue there. The battery also held the voltage quite good under heavy current pulled from it, so your battery cells seem to be good as well, just an issue with the calculated SOC. Could be a BMS issue. New firmware might fix the issue if it is a known issue on their side that they might have fixed. Just be cautious with firmware updates in general as they carry some risk. Let them do any updates and make sure they will replace any hardware that they brick due to a bad firmware update.

 

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Your post doesn't surprise me. When the Sunsynk batteries are deployed as standalone as in a single unit they perform very well . Deye & Sunsynk as most will know have a logger that the inverter uses for logging as well as firmware updates. So when you parallel & have more than one inverter the firmware must be the same to pair successfully. The batteries also posses firmware versions & when you pair more than one again the firmware must be the same. The big challenge is how do you know what firmware is on the battery & even if you knew this info how can you update. So many installers were swayed to go out & get the 10 year warranty on these products based on the extension. I reserved my judgement on this for the problems you are already experiencing. The batteries need the same firmware otherwise this weird stuff happens. 

The same can be said for the HV 50kW Sunsynk. So many installers were excited by it but the testing at FW took more than 10 months & that is unusual. Simply put, Sunsynk is a quality manufacturer of equipment. However, market pressure & rush to get to market has hurt these last 2 products I have mentioned. The 50kW Sunsynk cannot parallel yet. Maybe they have solved the issue but why release the product when it's not ready yet??? Come on Sunsynk you have been better than this in the past !!

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29 minutes ago, Steve87 said:

Your post doesn't surprise me. When the Sunsynk batteries are deployed as standalone as in a single unit they perform very well . Deye & Sunsynk as most will know have a logger that the inverter uses for logging as well as firmware updates. So when you parallel & have more than one inverter the firmware must be the same to pair successfully. The batteries also posses firmware versions & when you pair more than one again the firmware must be the same. The big challenge is how do you know what firmware is on the battery & even if you knew this info how can you update. So many installers were swayed to go out & get the 10 year warranty on these products based on the extension. I reserved my judgement on this for the problems you are already experiencing. The batteries need the same firmware otherwise this weird stuff happens. 

The same can be said for the HV 50kW Sunsynk. So many installers were excited by it but the testing at FW took more than 10 months & that is unusual. Simply put, Sunsynk is a quality manufacturer of equipment. However, market pressure & rush to get to market has hurt these last 2 products I have mentioned. The 50kW Sunsynk cannot parallel yet. Maybe they have solved the issue but why release the product when it's not ready yet??? Come on Sunsynk you have been better than this in the past !!


Management want to sell more product, I bet you engineering is screaming, but getting ignored, been there, got the t-shirt.

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Management get what they want for the medium term. But in the long run the name suffers. Keith as the CEO & an engineer one would have maybe seen a different outcome. But the price you pay for pushing a product when it's not yet matured in it's development is the school fees at the end. 

I will happily install their Low voltage residential range of equipment. I will also happily install the 50kW HV machine, but I know the limitations of the machine not being able to parallel & so therefore it's a 50kW Deadend deal. 

Having worked with ATESS on a HV high kW project I must admit that company is ready for good business & their product is well placed & robust enough to scale massively to up to 2MW. We have an issue with a component failure. A 400A Contactor & this has been made a available in the coming days. Now one can have a closed box design like a Sunsynk or you can actually expose the entire architecture & therefore allow the machine to be serviceable by a support engineer. I must admit I prefer the support engineer route. 

Tool 6 weeks to repair a 12kW Sunsynk recently. Took all but a week to get a faulty Contactor sorted. I think if you want to play in this game you need to gauge. & Gauge very well. 

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Thanks for the good info, definitely gives me some peace of mind,

Yes cap is set at 208 

Also interesting fact is, the installers didn't really know what they where doing,

  • CT Coil was reversed i had to explain that to them so they could fix
  • They lost their mind when my non-essentials (GRID) where at 9kw, had to explain to them them that's not a problem its read from CT
  • I had to set up the inverter to power my non-essentials via PV after i asked them to fix the CT coil
  • Master and slave configuration was not set correctly on bat, see below 

So on the batteries i had this problem that they only want to pair up correctly if i use the left battery as the master, the installers had the right as the master and it wasn't really working because it wouldn't power them both on or off by powering the master on/off.

I swapped the cam and link cables so the other one is the master and now i can power them both on and off by powering on/off the new master 

Point being i do think there is a firmware mismatch

 

Way to worried to get the original installer to to the upgrade and i don't trust any of there Cowboys :D not sure what im going to do, i will call around i guess and see who knows the most about the topic.

 

image.png.1adda7e127ab309a119dec69f2a04ba2.png

Edited by VinceG
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12 minutes ago, VinceG said:

Does anyone know if the Batteries should be upgraded in stages or can you take it straight to the latest version?

How do you even know what version they running?

It is very dangerous territory to update the firmware on the BMS. Usually manufacturers tweak the hardware here and there, so there might be incompatibilities between certain versions of hardware and firmware.

A safer route would be to run the batteries in voltage mode. Simply unplug the BMS comms cable and set the bulk, float and shutdown voltages manually on the inverter. The BMS will still balance your cells and protect against things, however the bad SOC value will no longer cause issues.

Edited by HendrikBigChief
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49 minutes ago, VinceG said:

So on the batteries i had this problem that they only want to pair up correctly if i use the left battery as the master, the installers had the right as the master and it wasn't really working because it wouldn't power them both on or off by powering the master on/off.

I swapped the cam and link cables so the other one is the master and now i can power them both on and off by powering on/off the new master 

Point being i do think there is a firmware mismatch

Maybe it was the DIP switch settings. 

Go to https://www.sunsynk.org/532kwh-battery and scroll down to "helpful documents".

This could explain what you experienced. If they set the RIGHT DIP switches to 010000 and the left battery was still set to 000000 then the left battery was the master all along, and the installer got the wrong left when he was connecting.

Check this - maybe it's not the firmware.

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1 minute ago, Bobster. said:

Maybe it was the DIP switch settings. 

Go to https://www.sunsynk.org/532kwh-battery and scroll down to "helpful documents".

This could explain what you experienced. If they set the RIGHT DIP switches to 010000 and the left battery was still set to 000000 then the left battery was the master all along, and the installer got the wrong left when he was connecting.

Check this - maybe it's not the firmware.

I dont have the rack mount batteries, the model i have does not have a dip switch, im pretty certain 

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2 hours ago, VinceG said:

I understand, 

Why is there an option to update the firmware then,

Like will Sunsynk then rather not advise updating batteries firmware?

It is there as a last resort once the units are out in the field. Best to try fixing the issue in any other way such as using voltage mode before messing with firmware. 

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2 hours ago, VinceG said:

I dont have the rack mount batteries, the model i have does not have a dip switch, im pretty certain 

They don't have shelves in the warehouse for master batteries, 1st slave batteries etc. And your swapping of the cables shows that one was configured to be slave and one master. So there is a way to configure each battery for it's place in the chain.

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