Sol-Ark 15K Battery Voltage Regulation Issues

[widget4145]

Unrealistic expectations of accuracy it would seem, 0.5V of 50 volts is 1%, that close to laboratory grade equipment and for 16S batteries 31 millivolts per cell, so its the setting that should be adjusted or the battery and it would be way to close if this knocks a BMS offline.

I would agree with you if its a matter of efficiency.

But no. In my case, whenever TOU is enabled, it deliberately pull the voltage down, and when TOU is disabled, it pushes the voltage to where you set it.

So clearly, something has offset in the firmware side, not an efficiency issue, or a matter of laboratory grade equipment. If it can give the requested voltage when some feature is disabled, and not when enabled, clearly it does say something in the software side.

Or in the OP's case, when there is no grid, or when there is excess solar, always that magic 0.5v figure.

And 0.5v matters.

For example, you set 3.45vpc balance start, that is 55.2v for 16s. How can it balance if inverter only gives 54.7v?

Or in the JK Inverter BMS's case, how can it proceed to float mode if it never reach absorption voltage, e.g. 55.2v?

Just compensate it? Nah, a bandaid solution. What if there is no grid? Then we are overshoot of 0.5v? Do we always have to watch our inverters so this wont happen?

 

[Ampster]

For example, you set 3.45vpc balance start, that is 55.2v for 16s. How can it balance if inverter only gives 54.7v?

That is why I used a calibration table when I was using the inverter voltage and settings like the balance voltage are at the .05 voltage increment. Now with closed communication, I do not have to worry about those details.

 

[Brightside]

It would be easy to just compensate for the 0.5V, if that was just an offset. It would actually be preferable to have this as the problem, as it is a constant.

The problem is, sometimes there is a 0.5V offset, and sometimes there is a 0.0V offset. It depends on multiple factors. So, it is a variable, with no way to properly deal with it, as it always varies based on certain conditions that vary.

So, right now the sun is shining and I have more power available than I need and the grid is connected but I'm not selling all of it, so that means I'm absorbing and floating 0.5V above my Voltage setpoints(this is also true for closed loop comms, I would be 0.5V above what the battery BMS is asking the inverter for).

I would be nice to just set the setpoints(with an offset if necessary to compensate for something) and have the system respect them all the time, not just some of the time.

 

[Ampster]

The problem is, sometimes there is a 0.5V offset, and sometimes there is a 0.0V offset.

In my case it was a predictable offset that did not vary by more than 0.1 volt, which at 50 plus volts could have been a rounding factor. But in your hypothetical or actual case it has to be dealt with differently.

 

[widget4145]

It would be easy to just compensate for the 0.5V, if that was just an offset. It would actually be preferable to have this as the problem, as it is a constant.

The problem is, sometimes there is a 0.5V offset, and sometimes there is a 0.0V offset. It depends on multiple factors. So, it is a variable, with no way to properly deal with it, as it always varies based on certain conditions that vary.

Exactly this point.

I'm glad some people have their systems working as intended, but some of us have issues with a common denominator, 0.5V of unpredictable offset. Well... in my case, is predictabe and dependent with TOU and grid, I could have just use HAOS and be done with it but unreliable and not a standalone system anymore, or they could just fix it, because why not?

Some can be traced as far back 2021.