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Sunsynk 8kW Inverter + 5kWh battery at 97%


Paulmic

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Hi All

Please can someone provide some advice on the below? I went live with an 8kW Sunsynk inverter, 2 x 3.4kWh Pylontech batteries (on loan) + 6 x 545W PV panels. For the first 2 weeks, the pylontech US3000 batteries always charged up to 100%, maintained 100% and gradually discharged during load-shedding. 

The example below of Pylontech batteries maintaining 100% charge:

image.thumb.png.67e4548ee6a515dc99986062c28165a5.png

 

My Sunsynk battery finally arrived this week and I've noticed it charges up to 100% after load shedding, then drops from 99% to 97% during the course of the day.

Is this normal, should it sit at 100% with trickle-charge?

image.png.85d06c5344b63052fb18670fd5e43753.png

The example above shows a trickle charge of 15W and 97% SOC.

You can see in th below example how the battery charges up to 100% after loadshedding and slowly drops down to 97% (almost every 4 hours it drops 1%).

image.thumb.png.a1a15b0319811710ba76f2633fa62e62.png

 

Is this running as expected?

Tks, 

Paul

 

 

 

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On 2023/05/05 at 3:51 PM, Paulmic said:

Hi All

Please can someone provide some advice on the below? I went live with an 8kW Sunsynk inverter, 2 x 3.4kWh Pylontech batteries (on loan) + 6 x 545W PV panels. For the first 2 weeks, the pylontech US3000 batteries always charged up to 100%, maintained 100% and gradually discharged during load-shedding. 

The example below of Pylontech batteries maintaining 100% charge:

image.thumb.png.67e4548ee6a515dc99986062c28165a5.png

 

My Sunsynk battery finally arrived this week and I've noticed it charges up to 100% after load shedding, then drops from 99% to 97% during the course of the day.

Is this normal, should it sit at 100% with trickle-charge?

image.png.85d06c5344b63052fb18670fd5e43753.png

The example above shows a trickle charge of 15W and 97% SOC.

You can see in th below example how the battery charges up to 100% after loadshedding and slowly drops down to 97% (almost every 4 hours it drops 1%).

image.thumb.png.a1a15b0319811710ba76f2633fa62e62.png

 

Is this running as expected?

Tks, 

Paul

 

 

 

The Synsynk batteries do not trickle charge (neither did the Pylons). They are not Lead Acid batteries. Once they reach 100%  SOC the BMS will stop the charging cycle.  Your inverter might be showing a small charge but none of that is making it into the cells.

Likely what is happening is that the cells are balancing which will cause a gradual and slow decline in SOC as the voltages of the cells (with the higher voltages) are brought down. A 3% drop in SOC does seem a bit excessive, but it might be due to these batteries being new with resulting higher cell imbalances.

The behaviour should normalise after a few days.

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7 hours ago, I84RiS said:

The Synsynk batteries do not trickle charge (neither did the Pylons). They are not Lead Acid batteries. Once they reach 100%  SOC the BMS will stop the charging cycle.  Your inverter might be showing a small charge but none of that is making it into the cells.

Likely what is happening is that the cells are balancing which will cause a gradual and slow decline in SOC as the voltages of the cells (with the higher voltages) are brought down. A 3% drop in SOC does seem a bit excessive, but it might be due to these batteries being new with resulting higher cell imbalances.

The behaviour should normalise after a few days.

Thanks for the info I84Ris - I’m definitely monitoring with my solar installer to see how things balance out. Sunsynk are also going to upgrade the inverter firmware so let’s see how things go 👍

 

 

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Hi @Paulmic

One thing you should be aware off (pretty sure your installer would have told you already), maximum discharge amperage on the Sunsynk 5.1kw is 100A, recommended is 50A. 

These amperage limits from the battery, will put a limit on the power that your inverter can produce when supplying exclusively from battery of max +-5kw & recommended 2.5kw of power.  

If you have either solar or grid power available the inverter will pull the extra required power from them, but only when that option is available, otherwise your inverter will trip out with an error. 

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Just an update on this thread. This appears to be a BMS function, thats the only explanation I have. After load-shedding I see the battery charges up to 100%. Then after 1 hour of being fully charged, it dropped to 99%. After 3 hours it dropped from 99% to 98%:

 

image.thumb.png.2bad8d9fdd2c0eade550210b89a0c682.png

 

For interest, here are my Inverter/battery settings:

image.png.534b4c9e6c7037964295998d92c6284f.png

image.png.6724bd9c7ab8a4500e27e70d4d5014e2.png

 

 

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