Classic entering float with 90% SOC

[dgd]

If you don't have a WBjr connected to your Classic then to keep things simple don't bother trying to terminate Absorb using any EA figure, just use the default 2 hour Absorb timer.
At least until you get a WBjr and then can measure with some accuracy the actual battery current.
dgd

[dapago]

Ok then. Will try to get the WBjr and start a new tread on that matter once I've got it installed. For the moment I will just raised the absorb voltage and/or time and try to get the batts 100% SOC at entering float with those 2 settings.

[Vic]

Hi dapago,

We do not know too much about your system.

Many systems already have the 500 A 50 mV Shunt installed in a DC Conduit box (called different things by different manufacturers).

If your system does not already have this 500 A Shunt,  then you should order it as well:
https://www.solar-electric.com/catalogsearch/result/?q=500+a+shunt

The Deltec Shunt is quite common.   MidNite also offers a shunt,  that has two extra holes for the MN Shunt busbar,  which might help you rewire things easily.

If you are not going to try using the Classic's EA function,  then you may want to watch the SGs for a week or two,  as you try to dial-in the Absorb time that will allow fully charging your batteries,  at least twice per week.

Your battery bank is not huge,   so,  perhaps your system will really need to be recharged every day.

FWIW,   Vic

[dapago]

My needs are not huge either. For now my needs are ~ 2.5 kwh daily and in the morning before the sun kick in, I am ~ 80% SOC. My needs will raised in the future to ~4KWH.
I'd like to try the EA function but still can't get my head around what figure in Amp I should enter. I still don't know if the EA function limits the Amp to the figure entered or does something else. On the other side, I don't see the reason to use the EA if without it,I am reading ~ 5Amp in the CC display near the end of absorb... But my batts don't get to 100% SOC.

What I know is that in float mode the CC shows ~ 2.5 Amp and near the end of absorb (I change the voltage to 59.3 and raised the time to 2h30 yesterday)  it shows ~5Amp. Today took a SG reading at float and still not getting 100% SOC but better than yesterday. Today I raised the ABsorb time to 3 hours and will see tomorrow.

[dapago]

If you don't have a WBjr connected to your Classic then to keep things simple don't bother trying to terminate Absorb using any EA figure, just use the default 2 hour Absorb timer.
At least until you get a WBjr and then can measure with some accuracy the actual battery current.
dgd

With 2 hours absorb time I enter float and my batts are not 100 % SOC in sunny day. This is the reason of my post. I could just raised the abs time but wanted to see if the EA function could help.
At the end I will certainly follow your advice and just not use EA.

[Vic]

Hi dapago,

Fine on your changes to Vabs and Absorb time.
Just wait a few days to see what effects the changes will make on the SGs.

BTW, what Hydrometer are you using.

Also,  believe that you are in the Tropics,   so,  if your batteries are warm,   SG readings will probably need to be Temperature Compensated.

What SG reading are you using as an indication of 100% SOC?
What is the Temperature Compensation value in the Charge> R-Comps are you using?

Sometimes we need to wait a few days of charging to see the effects of changes to Vabs and or Charge time,  make with the your SG readings.

FWIW,   Vic

[dgd]

With 2 hours absorb time I enter float and my batts are not 100 % SOC in sunny day. This is the reason of my post. I could just raised the abs time but wanted to see if the EA function could help.
At the end I will certainly follow your advice and just not use EA.

So you are seeing the SOC increase to 90% while charging in Absorb, then the SOC changes to 100% when charging changes to float?
Where exactly are you seeing this SOC reading as I thought it was only calculated properly when using a WBjr with the Classic.
Or have use ascertained the SOC using a hydrometer to measuer the battery SG?
I would be confident that after a 2 hour timed absorb that you battery bank is 100% SOC

dgd

[dapago]

Hi dapago,

Fine on your changes to Vabs and Absorb time.
Just wait a few days to see what effects the changes will make on the SGs.

BTW, what Hydrometer are you using.

Also,  believe that you are in the Tropics,   so,  if your batteries are warm,   SG readings will probably need to be Temperature Compensated.

What SG reading are you using as an indication of 100% SOC?
What is the Temperature Compensation value in the Charge> R-Comps are you using?

Sometimes we need to wait a few days of charging to see the effects of changes to Vabs and or Charge time,  make with the your SG readings.

FWIW,   Vic

I am using an hydrometer I bought in a battery shop. Could it be inaccurate? No many choices here.

I am using 1.277 SG  for 100% SOC.

The CC is set to Compensate temperature in Temp-Comp setting (-0.005V per degree C)

My battes never get hot or warm even when EQ and that surprised me. But gazing all right (strong smell and bubbles sounds)

[dapago]

Dgd
I am seeing 90% in float using an hydrometer and since increasing absorb V + absorb time to 2.30h yesterday I am seeing ~95%.

It is sunny generally every day (I am in the tropics). I get float every day at ~1pm/2pm with still 2/3 good hours of sun to go. When cloudy (white clouds) I read ~1000 watts and with dark clouds ~500watts. At the end of the day, on average when CC is resting, I harvested ~4 to 5 KWh (CC display). If I EQ at 1pm, I read ~1800/1900 watts IN on the display.

With my CC 150 wired 3s,2p I always reached 100 SOC every day around 1pm whatever the weather conditions with max 2 hours absorb time.  With my new 200CC, 2 more panels and just an other inverter fridge added to the load, 2 hours absorb time is not enough apparently and some cloudy days I am not getting float.  I would have thought that with 2 more panels I would have got the same charging patern (float every day at 1pm whatever the weather condition)

[dgd]

I would still be intending to get a WBjr/Deltec shunt (or get an MN Epanel or MNDC) then use the battery monitor reporting in the local app.

I have set up a few systems using 225Ah FLA batteries and have never had an problems with the default 2 hour Absorb time (at 29.2v) getting the cells to 100%. But then I tend to size capacity ro never get below 75 to 80% capacity with FLAs.

If you are only seeing 90% after 2hr Absorb then I'm guessing the bank must be starting out at a well discharged state. If you are down to 50 to 60% SOC then that would make me think the capacity of the bank is too small.
Have you actually checked the SG in all of the cells?
What are your Absprb and float voltages and have you done any EQ yet?

dgd

[boB]

Maybe you need to EQ the batteries to get some of that sulphate off the plates and back into the electrolyte ? 

Also, while charging, are all of the batteries at the same voltage ? They should be fairly
well balanced.

Could some batteries be in better shape than the others ?

Make sure the water/electrolyte  level is covering the plates and then some of course.

boB

[dapago]

I would still be intending to get a WBjr/Deltec shunt (or get an MN Epanel or MNDC) then use the battery monitor reporting in the local app.

I have set up a few systems using 225Ah FLA batteries and have never had an problems with the default 2 hour Absorb time (at 29.2v) getting the cells to 100%. But then I tend to size capacity ro never get below 75 to 80% capacity with FLAs.

If you are only seeing 90% after 2hr Absorb then I'm guessing the bank must be starting out at a well discharged state. If you are down to 50 to 60% SOC then that would make me think the capacity of the bank is too small.
Have you actually checked the SG in all of the cells?
What are your Absprb and float voltages and have you done any EQ yet?

dgd

I am down ~75% SOC in the morning. Not check all of them but 1 in each batt. I raised Absorb to 59.3 and float at 54. I did an EQ and then I get 100% SOC. Now it is sunny every day every days and only then I get 100% SOC at noon and it stays like that until dark.

[dapago]

Maybe you need to EQ the batteries to get some of that sulphate off the plates and back into the electrolyte ? 

Also, while charging, are all of the batteries at the same voltage ? They should be fairly
well balanced.

Could some batteries be in better shape than the others ?

Make sure the water/electrolyte  level is covering the plates and then some of course.

boB

I did an EQ yes. 100%SOC after 20mn. Yes all the batts are the same voltage and 6 months old. Water electrolyte is well over the plates level so that is not the problem. Absorb is now set to 2h30 at 59.3. From now on, sun will be shinning every day for 6 months so maybe I should lower absorb time to 2h and see what happens.

[Westbranch]

dapago, you need to measure the SG and please post it here for review...  so we can see just what happened...this should not be a one or 2 day recovery...