Local App - SNAFU :-|

[Westbranch]

Well that (0.005) is a very small gain in SG, so you still have 12 more hours of 1 amp charging to go... 

What did the vendor say to do after that?   A load test?

[Lya72]

At this moment, I plugged the Battery Bank to the Classic.

It was a day with little sun in the morning and more in the Afternoon, so that, after learning Erik's instructions, after the end of the absorb period, I switched to a manual EQ at 30.0V for an hour.

At the end of this EQ hour, the SG has gone back to 1.24 on the four batteries. (pictures will be joined tomorrow), so I'm in dubitative mode !!

Yann

[SolarMusher]

1.265 is fine.
30V is not an EQ voltage! 31V mini to 32.2V max, say 31.5V would be better on your system.
If your battery SG is 1.265 +/- 0.005 from cell to cell, you don't really need to EQ. Connect and set your Classic with the correct parameters and do not allow SG to go below 50% DOD (SG 1.200), when at 50%, plug your charger all night to raise SG to 80/90% SOC and the Classic will do the rest of the job. You will have to find the right time to absorb these batteries, but 4amps End Ampere (plus loads) is a good value to begin.
It seems that these batteries were chronically undercharged but not really sulfated.
Erik

[Vern Faulkner]

There have been many here who have basically said the same thing: you need to really push some major current through your batteries. A good absorb charge, followed by a good four-eight hours of equalize charge at C/10 or thereabouts.

Your supplier, to be honest, is clueless for suggesting a one-amp charge current. that's a float current.

[ClassicCrazy]

I have read through this whole discussion. One thing I have not seen mentioned is the temperature of the batteries and if the temperature compensation remote is mounted properly with the batteries , and also if the recommended temperature coefficient parameter is set in the Classic.

When I was new to solar I ruined my first battery because the charge controller didn't have temperature compensation - so the battery was cold , the voltage the controller gave the battery wasn't high enough to compensate for the cold. That meant the battery never filled up all the way, and I kept taking power out of it .

But that was a good learning experience and it was only one 12v battery to replace.

[Lya72]

Erik,

Sorry for the delay to answer but I was waiting sun to be in EQ mode and to understand why my limit was put at 30.0V.

So Today, there was sun in the afternoon and in EQ mode at 31.0V, my VICTRON Phoenix inverter 24V / 350va shutted down in error.
It goes up at 30.7 Volts.

After searching in his documentation, I found that :

"For correct operation, the battery voltage should be between 0.88xVnom and
1.25xVnom where Vnom is 24V, ie  21.12V / 30.0V !!
The inverter shuts down when the battery voltage is below 0.88xVnom or above
1.3xVnom" ie 21.12V / 31.2V"



So after 3 hours of EQ and tests , 30.7V was the maximum admissible voltage for the inverter.

[SolarMusher]

You really need a Iota charger plus IQ4 to charge and equalize to 31/32V your battery set...
Erik

[Lya72]

Erik,

Actually, there's Sun in France and I'm searching how put a maximum of power in the batteries.

It seems that I'm wasting Sun (Absorb is set to 4:00 and EA 3.5A for the loads,     going from 600Wh to 112 Wh) and Batteries aren't full  and  SG is going down each day :

Yesterday : 1.23 after 2.9 Kwh IN and 2.4 kwh OUT

and today : 1.21 after 1.8 Kwh IN and 1.4 Kwh OUT

Yann

PS : Temps are compensated (Absorb set at 28.6V goes to 29.2 and now 29.8V since I elevated EQ voltage from 28.6 to 30.7V ! Note that EQ is not compensated.


Do you think that these charge settings are insufficients until I unplug my inverter and elevate EQ to 31.5V ??   So my panels will just serve to charge the batteries ??

[dgd]

Erik,

Actually, there's Sun in France and I'm searching how put a maximum of power in the batteries.

It seems that I'm wasting Sun (Absorb is set to 4:00 and EA 3.5A for the loads,     going from 600Wh to 112 Wh) and Batteries aren't full  and  SG is going down each day :

Yesterday : 1.23 after 2.9 Kwh IN and 2.4 kwh OUT

and today : 1.21 after 1.8 Kwh IN and 1.4 Kwh OUT

Do you think that these charge settings are insufficients until I unplug my inverter and elevate EQ to 31.5V ??   So my panels will just serve to charge the batteries ??

Yann,
I would increase the absorb voltage and absorb time but i don't think that is the best solution.
The power in looks too low for the power you take out, they are discharging more each day.
Since they finish absorb each day but still cannot cope with the day's load it would seem to me that they are not of sufficient capacity - either sulfated,  damaged or Ah rating too low.
dgd

[SolarMusher]

Do you think that these charge settings are insufficients until I unplug my inverter and elevate EQ to 31.5V ??   So my panels will just serve to charge the batteries ??

Yann,
I would not set Absorb voltage higher than 29.4V for these little batteries. However, 3.5amps EA seems to be a good value for a 16W/hr load.

Yesterday : 1.23 after 2.9 Kwh IN and 2.4 kwh OUT

How do you know that you really had 2.4kw/hr out for yesterday, without a battery monitor...?
You told us that you have 375Ah daily load, where did these 2kw go? To the grid?
Why don't you wait for Float time to feed the grid or other loads  ?
As dgd said, too much Ah/Out or not enough Ah/In.
In Fall/Winter, you should use your system only to supply 0.9kw/hr max daily with 3 days autonomy, no more and charge it at 50% DOD from the grid when cloudly. You need absolutely to have these batteries fully charged 2 days a week or more.
Erik

[Westbranch]

Yann, what you are doing is called DEFICIT CHARGING

Using your numbers:

#1 we assume your battery is fully charged - which by the way IT IS NOT FULLY CHARGED @ SG 1.23

#2  2.4 KWh out needs 2.4 x 1.15 to replaces it so on day 2 you need at least 2.76 Kwh to replace the 2.4 due to battery inefficiencies etc.

#3  we need 2.76 KWh to break even but we only get 1.80Kwh so we are short -.96 Kwh

#4  now just to break even we need more since you again sold 1.4Kwh. 

#5 To break even we need at least .96 + 1.4 Kwh x 1.15 = 2.57 Kwh

you are killing your batteries again.

[Lya72]

Thanks to all for your detailed explanation.

OK, today, I will test, just with the batteries, no Inverter.

#1 we assume your battery is fully charged - which by the way IT IS NOT FULLY CHARGED @ SG 1.23

The night before, it was SG 1.24

#2  2.4 KWh out needs 2.4 x 1.15 to replaces it so on day 2 you need at least 2.76 Kwh to replace the 2.4 due to battery inefficiencies etc.

OK, it was fine, because of a production of more than 2.9Kwh that day.

#3  we need 2.76 KWh to break even but we only get 1.80Kwh so we are short -.96 Kwh

With your calculation, I needed 1.44Kwh * 1.15 = 1.656 Kwh.
That was fine, because I had 1.8 Kwh.

Where's the deficit ??

Even with a production that's more than the loads, SG declines from 1.24 to 1.23 and 1.22 .

I would not set Absorb voltage higher than 29.4V for these little batteries. However, 3.5amps EA seems to be a good value for a 16W/hr load.

Absorb Voltage is set at 28.6V (default value), that's the compensated temps that elevates it to 29.8V.

How do you know that you really had 2.4kw/hr out for yesterday, without a battery monitor...?

It's a simple addition of all loads :
Constant : 375 Wh
Inverter + NAS : 1440 Wh
Micro-Inverter : 585 Wh (2:30 at 236 Wh) injected in the grid


The micro-inverter was manually plugged during the EQ mode, after the Bulk and Absorb modes ended, getting power  that was wasted.
That's why this day, the production was so high !

Yesterday, there was more sun  and the production was just 1.8 Kwh ! 


The batteries can't absorb all the input.


Yann

[Westbranch]

Simply put:  If your SG is dropping, there is deficit charging.

day 1  SG = 1.24
day 2  SG = 1.23
day 3  SG = 1.21

this shows you are not replacing what you are taking out!

If you had a stable SG you would be replacing what you took out

[dgd]

How do you know that you really had 2.4kw/hr out for yesterday, without a battery monitor...?

It's a simple addition of all loads :
Constant : 375 Wh
Inverter + NAS : 1440 Wh
Micro-Inverter : 585 Wh (2:30 at 236 Wh) injected in the grides

Yann,
You may be underestimating the load wattage
for example: How efficient are these inverters?   the micro inverter 85-90% ? 585wh probably took 650wh
And the batteries may be less efficient due to their age, sulfation etc..

In any case the calculations are not correct as the batteries are discharging every day.
Have you managed to do an EQ at 31.5v for 3 to 4 hours?

dgd

[SolarMusher]

Absorb Voltage is set at 28.6V (default value), that's the compensated temps that elevates it to 29.8V.

Set your Absorb at 29.4Vdc. 28.6V is too low!
Rather than stocking energy in your batteries to power your loads for the next three days, you're taking this energy off of your batteries to feed the grid/inverter... 
Obviously, you're trying to use each watt that your system can produce, I'm afraid that it's not possible without monitoring and growing your PV array.
Listen to dgd and West, your batteries are only 80% efficient so you need to push 20% more amps to reach your 100% SOC.
Without a battery monitor, you're like a blind guy trying to perform in a car race...
The mistake you've made from the begining is to believe that you could monitor your system from the loc app, loc app could only monitor your classic but will never monitor your battery system. Datas from loc app are only from the Classic, you will never know anything else.
I think that you just don't understand how solar works. You need to replace all amps used and add more for battery ineffeciency.
Why don't you want to buy a cheap/simple batt monitor
Erik