Understanding the SOC % in the App

[binkino]

I have a question about the app displays me.

Battery charge:
If I take this http://www.marxrv.com/12volt/voltchart1.gif as refference, and what I read in the web,
if the batteries are discharged and come back to 12 Volt each, they are healthy discharged and have about 50% charge left in.
Also the battery manufacturer recommends not to discharge under 12 Volts for a long battery life.

In my system, I control the inverter via the AUX1 and a relais connected to it
and set "Low Bat Disconnect" with 46 Volts at 2 seconds discharging
and switch back to battery at 51 Volt
(see my question post about more AUX channels!)

If it reaches the 46 Volts and it has switched the inverter back to mainpower, and the batteries are not longer discharged, and I wait a time, the batteries come back to 48 Volts, so 12 volts each.
Once I played around, and discharge to 45 Volts, the batteries come back to 47,4...47,7 Volts. That is to low. So I discharge max. to 46 Volts.

But the App shows me at 46 Volts ~ 85 % discharge / left energy then.
Shouldn't it display me about 50% ?
Is this calculated by the used Ah and the maximum Ah ... where is my fail in thinking here?


With the Capacity it tels me total capacity is 242 Ah and used 38 Ah, and left is 204 Ah - math. correct
But is there not more Energy I can use?
Shouldn't it give me 1/2 of the 230Ah ... mh ... can you please cut down the trees, so I can see the forrest?
(we say so)


I am confused about this and if you can help me find the point so I understand this



I am also using Grahams great Android App, that gives me some more information from the Classic Lite
This App only displays datas coming from the Classic, so the question is behind the charger itself, why it display me the left energy in higher % than it is?

btw I have also installed the WBJr.



I believe my wiring of the system is correct ...
* the WBJr is in the negative line close to the batteries
* the Classic negative is direct at the inverter
* the Classic plus is at its fuse at the fuse box
* battery plus is at its fuse at the fuse box
\ then the fuses are connected to the inverter with one big wire

So i don't guess the meassuring is wrong?



thanks

[Resthome]

I have a question about the app displays me.

Battery charge:
If I take this http://www.marxrv.com/12volt/voltchart1.gif as refference, and what I read in the web,
if the batteries are discharged and come back to 12 Volt each, they are healthy discharged and have about 50% charge left in.
Also the battery manufacturer recommends not to discharge under 12 Volts for a long battery life.

In my system, I control the inverter via the AUX1 and a relais connected to it
and set "Low Bat Disconnect" with 46 Volts at 2 seconds discharging
and switch back to battery at 51 Volt
(see my question post about more AUX channels!)

If it reaches the 46 Volts and it has switched the inverter back to mainpower, and the batteries are not longer discharged, and I wait a time, the batteries come back to 48 Volts, so 12 volts each.
Once I played around, and discharge to 45 Volts, the batteries come back to 47,4...47,7 Volts. That is to low. So I discharge max. to 46 Volts.

But the App shows me at 46 Volts ~ 85 % discharge / left energy then.
Shouldn't it display me about 50% ?
Is this calculated by the used Ah and the maximum Ah ... where is my fail in thinking here?


With the Capacity it tels me total capacity is 242 Ah and used 38 Ah, and left is 204 Ah - math. correct
But is there not more Energy I can use?
Shouldn't it give me 1/2 of the 230Ah ... mh ... can you please cut down the trees, so I can see the forrest?
(we say so)


I am confused about this and if you can help me find the point so I understand this



I am also using Grahams great Android App, that gives me some more information from the Classic Lite
This App only displays datas coming from the Classic, so the question is behind the charger itself, why it display me the left energy in higher % than it is?

btw I have also installed the WBJr.



I believe my wiring of the system is correct ...
* the WBJr is in the negative line close to the batteries
* the Classic negative is direct at the inverter
* the Classic plus is at its fuse at the fuse box
* battery plus is at its fuse at the fuse box
\ then the fuses are connected to the inverter with one big wire

So i don't guess the meassuring is wrong?



thanks

First off the voltage charts are not a very accurate way to measure SOC IMHO. The only way is to measure the S/G with an accurate hydrometer. And the batteries have to be measured with no loads after so many hours for that chart to make any sense.

As for the total capacity â€" it is based on what you have told the Classic your AH capacity of the batteries are at 25C and normally the 20hr rating. The Classic adjust your AH Capacity based on the temperature of the batteries.

There is also a Classic setting for battery efficiency (how old they are and other factors). You have to put more AH back in than you take out to fully recharge your batteries. I believe the default is 92%. Mine is set to 90% so if I take 100AH out I need to put back at least 110AH before it would reach 100% SOC.  There are other SOC parameters that the Classic does not take into account so while it is close it is not perfect, thus you need to measure the S/G of the batteries to really tell the SOC.

[binkino]

Hi Resthome,

thank you

I have AGM batteries, at 20°C it is 230 Ah
I set this in the Classic settings

Efficiency is here default 94%
and Capacity is set to 230 Ah
1%/t

and

Temp.comp.
-3mv/°C/cell
Temp.Window 20°C


0.018V per Block = 18mv : 6cells = 3mV ?

here: http://www.midnitesolar.com/FAQ/index.php?topic=56.0
he writes, 2V = 1 cell .. but 4 batteries = 24 cells
and 24 * 3mV would be 72mV ? not possible ?



I have these batteries:
http://www.winnerbatterien.de/autobatterien/Versorgungsbatterien/AGM-Versorgungsbatterien/SOLAR-FREE-VRLA-AGM/AGM-Versorgungsbatterie-230Ah::244.html
The Datasheet PDF: http://www.winnerbatterien.de/Produktdatenblatt/Winner-WF230-SolarFree.pdf


the 20hr rating --- C20 ? This is in the datasheet 228Ah