Equalisation or Boost charge happening to often? Steca 2010 MMPT Auto Equalising.

[Handmade Matt]

Hi everyone.
Thanks for all the previous help in building my system. It's been working really well. I'm super chuffed. So I'm not really concerned about what I'm witnessing, just interested to know what's going on.

In short it's a 490watt array with 250ah 24v battery bank. It's charging with the Steca 2010 Solarix MPPT controller.
I have never taken the battery bank below 24volts. Day to day use is seeing us probably only using 10-20% capacity.

In the Steca data it says that it will perform an equalisation every 30days and I think that's only triggered when the battery bank voltage drops below a certain figure? "Reset Voltage" (Correct me if I'm wrong.)

The Steca data says
End of charge 27.8volts (I normally observe 27.3volts with only 0.3amps when the bank is full..?)
Boost charge 28.8volts (This is the voltage that I am witnessing fairly regularly)
Equalisation charge 29.4volts (I've never seen this voltage... Maybe I've just not happened to look at my dials when it was happening? Or it hasn't yet been required?)
Reset Voltage (SOC/ LVR) 25volts (This I believe is the trigger for Boost or Equalisation charges?)

As I said, I'd love to know more about what's going on.
Thanks

[Sunking]

The Steca data says
End of charge 27.8volts (I normally observe 27.3volts with only 0.3amps when the bank is full..?)
Boost charge 28.8volts (This is the voltage that I am witnessing fairly regularly)
Equalisation charge 29.4volts (I've never seen this voltage... Maybe I've just not happened to look at my dials when it was happening? Or it hasn't yet been required?)
Reset Voltage (SOC/ LVR) 25volts (This I believe is the trigger for Boost or Equalisation charges?)

Hey Matt you just do not quite understand what the terms mean, but everything is normal.

Unfortunately TERMS are not Standardized and manufactures tend to use their own Jargon which adds the confusion factor. Typically Solar Chargers come with either 2 or 3 stage charging algorithms. Yours is 2-stage.

In a 3-stage charger they have 3 steps. First is a Bulk charge which is a constant current mode which is applied until the battery reaches voltage of about 28 volts on a 24 volt battery. Then it switches to Absorb mode which is a constant voltage - current taper about 28.8 volts until the current tapers to around 3% or a specified time. Then it switches to Float mode which is a constant Voltage of roughly 27.2 volts.

Your Two Stage is exactly the same as Absorb, and Float described above, they just use different terms.

As for Equalization there is no way a charge controller can determine if the battery needs an EQ charge as it cannot measure Specific Gravity or individual Cell Voltages. All they can do is put it on a automatic timer of say every 30 days, or manual operator controlled. Disable the Auto feature so you decide when to EQ.

The Reset means your controller has a Low Voltage Disconnect relay built into it. If you look you should have a Load Fused Output Port. IT will disconnect the battery from the Output Port if the battery voltage gets low, and will not reconect until the battery has been charged back to the Low Voltage Reconnect (LVR) has been reached.

[Handmade Matt]

Thanks again Sunking.
So in Steca jargon "Boost" = Absorb and "End of Charge" = Float?

There's one thing that I'm still unsure of though.
The manual and data, available from Steca HERE lead me to believe that the "Reset Voltage (SOC/ LVR) of 25volts" is different from the LVD on the load circuit of the controller because it also lists "Deep discharge protection (SOC/ LVD) of 23volts"
What does LVR mean?

This is a screen shot from the manual.


Additionally I don't think that the automatic equalisation can be turned off..?
Is anyone else familiar with this particular controller?

[Sunking]

So in Steca jargon "Boost" = Absorb and "End of Charge" = Float?

Correct.

What does LVR mean?

This is a screen shot from the manual.

OK notice LOAD CURRENT. That is the Load or Output Port I spoke of earlier that works through a relay in the controller and is triggered by a control circuit called LVD Relay.

LVD = Low Voltage Disconnect is the voltage point where the relay will open up and disconnect the Load Port from the battery to prevent the battery from being too deeply discharged.
LVR = Low Voltage Reconnect is the voltage at which the relay will close and connect the battery back to the Load Port