PV Voltage and Charging

[RobertA]

Anyway, my point again is that a manual setting should not take priority over Whiz-bang. If Whiz-bang's data indicates the battery is at so or so level, the Classic should follow.

[ClassicCrazy]

Anyway, my point again is that a manual setting should not take priority over Whiz-bang. If Whiz-bang's data indicates the battery is at so or so level, the Classic should follow.

The SOC is just an estimation of your battery - it is only as good as how you set it up and there are a lot of variables that can effect it. For example you have to set it's capacity and the efficiency . Not sure what you have that set for but if it is off then the SOC will be off. Seems like most people have to spend some time studying their batteries characteristics to really tweak it to get it close to accruate. But it does get you in the ballpark of knowing what went in and out of battery .

The Classic goes by Absorb, Float, equalize  setpoints and ending amps - SOC does not effect it.

The Whizbang just tells what actually goes into the battery via the external shunt ( make sure you have it set for external shunt ) . So it  can tell what part of the power the Classic is providing goes to loads and what goes to battery .

In your youtube schematic I can't tell where your external shunt is located in the wiring diagram. You should have only one cable from battery negative to shunt . On the other side of the shunt should be all the other negatives of the system - inverter , dc loads, classic , etc.

Larry

[ClassicCrazy]

I just saw your video on battery equalizers - I don't know about what those do but you may want to read this on your parallel strings

http://www.smartgauge.co.uk/batt_con.html

Larry

[RobertA]

Anyway, my point again is that a manual setting should not take priority over Whiz-bang. If Whiz-bang's data indicates the battery is at so or so level, the Classic should follow.

The SOC is just an estimation of your battery - it is only as good as how you set it up and there are a lot of variables that can effect it. For example you have to set it's capacity and the efficiency . Not sure what you have that set for but if it is off then the SOC will be off. Seems like most people have to spend some time studying their batteries characteristics to really tweak it to get it close to accruate. But it does get you in the ballpark of knowing what went in and out of battery .

The Classic goes by Absorb, Float, equalize  setpoints and ending amps - SOC does not effect it.

The Whizbang just tells what actually goes into the battery via the external shunt ( make sure you have it set for external shunt ) . So it  can tell what part of the power the Classic is providing goes to loads and what goes to battery .

In your youtube schematic I can't tell where your external shunt is located in the wiring diagram. You should have only one cable from battery negative to shunt . On the other side of the shunt should be all the other negatives of the system - inverter , dc loads, classic , etc.

Larry

Yes, shunt and Whiz-bang installed later. I will eventually edit.

I agree that fine tuning battery in-out is a struggle, but I am real close. As far as Whiz-bang relation to Classic I'd like the following support:
1) Using my hydrometer I indicate to Classic full charge. 'Click here if at full charge'
2) From thereon Classic utilizes Whiz-bang data to determine battery charge and applies bulk, absorb, float modes respectively.

Should not be so hard.

[RobertA]

I just saw your video on battery equalizers - I don't know about what those do but you may want to read this on your parallel strings

http://www.smartgauge.co.uk/batt_con.html

Larry

I used that exact reference to wire my battery bank. But as said in video, discrepancies still existed. Based on my observations today, I think electrical equalizing this is a good solution.

[ClassicCrazy]

I watched your video about your RV  solar installation.
Nice job squeezing all that PV on roof and how you got the batteries to fit in box you made.

I guess that will be especially important for temperature compensation probe in the battery box in case they get warm in there. Heat is one of the things that decreases battery life .

The settings are not set in stone - they also need to be tweaked over time and seasons. As batteries age they need to be changed a bit and I have found also that winter summer too depending on how they are used.

Larry 

[RobertA]

So true about temp, it's a major worry. The dog days of TX summer are not yet here and I'm already noticing peak temps per Classic phone app. Have not noticed Classic throttling back though. I guess I'll act then.

Edit: Thank you!

[ClassicCrazy]

I was just reviewing what voltages you have set for Absorb.
I know you said Deka had approved these ? Dealer or manufacturer ?
I found this chart for East Penn Deka
You have 29.1 for  Absorb - that is at the high range of what the attached chart shows - I would want a lower voltage at the range especially if the batteries get warm - raise the voltage as the batteries get older or colder in winter .
So Absorb 28.8 is where I would be at.
Float they show a range of 27.60V - 28.20V  and you have 27v so that seems too low for Float according to their chart.
Also look at what you have for equalize compared to their chart 30.00V - 30.60V

Temperature compensation is -3 mV / cell / °C

With your higher Absorb voltage setting it seems like you would be heating up your batteries more than maybe you need to , especially in enclosed space you have them in in hot climate perhaps ?

Just some things to think about - here is the chart I was looking at . Monobloc flooded
http://africanenergy.com/new/wp-content/uploads/2012/08/Renewable-Energy-Charging-Parameters.pdf

Hope this helps
Larry

[RobertA]

I talked to Deca directly but she was obviously just reading from her screen. Now have more confidence in fiddling with them, thanks!

Edit: I'm good with this (image). You may be an internet stranger but if Deca's recommended settings haven't worked so great I'm willing to give yours a shot. Thanks for all your input.

[Vic]

Hi again Robert ...

Let me try this again;

Please check in the Tweaks Menu,  is ARST set to ON?   If not,  it should probably be set to ON.

Each day,  the Classic should begin in Bulk-MPPT,  UNLESS you have set the number of Skip Days in the Charge>Advanced menu to a number that is not zero (0).  Have you checked this ??   Is Skip Days set to 0

If your batteries are not being fully recharged on each charge day,  the Absorb time needs to be increased,   the Absorb voltage needs to be increased,   EA needs to be set to 0,  the Depth Of Discharge (DOD) needs to be decreased (less discharge),   or,  if Skip Days is not 0,  it should be set to 0,  until the batteries become fully charged ...   fairly simple.

Does this make sense to you?

Thanks for any replies.   Vic

[ClassicCrazy]

I would lower the float and equalize to the minimums shown in those charts too.

Raise your Absorb time to 4 hours when you can watch it - you want to see if it gets to 100% SOC a bit before it gets to your ending amps setting of 5 amps that will change it to Float . Confirm with specific gravity reading . Then you can raise or lower the ending amps as needed. Not sure what you have your SOC efficiency setting for but you don't want it too high . I forget what Vic recommends - 90 or 92 % ?

And remember - the voltages you see may be different than the settings due to temperature compensation happening.
On Local Status app if you go to Config / Advanced / then look at Temperature compensation the temperature shown at the right in that frame is the Temperature compensated value of whatever state the Classic is in at the time . So if your Absorb setpoint was 28.8 and it shows Temperature compensated 28.5 then that is what the Classic is using .

Also if you have Android look up in forums   Grahams Android Classic app - it is great monitoring interface you would like. Available on Playstore .

Larry

[Westbranch]

The shunt the WBjr is mounted on HAS TO BE the last connection in the cable , before  the NEGATIVE post on your battery as the WBjr reads the amount of amps that go into the battery, not the amps the Classic outputs, and that is why you use the WBjr, to tell the Classic that X Amps are being put into the battery, and at that point the Classic  will  terminate Absorb and change into Float.

Losing water from the battery is not necessarily a bad sign .... it lets you know it is being properly charged....EXCESSIVE water loss is a problem.  How much water were you using to top up the cells?

[RobertA]

ARST is on, skip days is zero, I have no issue adjusting absorb time based on usage, temp compensation is 94 (new batteries), and my shunt is mounted properly.

"If your batteries are not being fully recharged on each charge day,  the Absorb time needs to be increased", "Raise your Absorb time to 4 hours when you can watch it", " you want to see if it gets to 100% SOC a bit before"

I know that if I wake up and SOC is under 75% I need to adjust absorb time up to 3 hours. I know that typically SOC is in the 80-85 range and absorb set for 2 hours will suffice. I don't want to fry battery by sitting in absorb for too long, that's why I adjust daily. But that should not be necessary. Why is no one addressing the elephant in the room? Absorb time should instead be done automatically by Classic based on Whiz-bang data. Does anyone know if that is being addressed? The Whizbang has more value if the Classic actually uses it

[ClassicCrazy]

ARST is on, skip days is zero, I have no issue adjusting absorb time based on usage, temp compensation is 94 (new batteries), and my shunt is mounted properly.

"If your batteries are not being fully recharged on each charge day,  the Absorb time needs to be increased", "Raise your Absorb time to 4 hours when you can watch it", " you want to see if it gets to 100% SOC a bit before"

I know that if I wake up and SOC is under 75% I need to adjust absorb time up to 3 hours. I know that typically SOC is in the 80-85 range and absorb set for 2 hours will suffice. I don't want to fry battery by sitting in absorb for too long, that's why I adjust daily. But that should not be necessary. Why is no one addressing the elephant in the room? Absorb time should instead be done automatically by Classic based on Whiz-bang data. Does anyone know if that is being addressed? The Whizbang has more value if the Classic actually uses it

You are missing something - the Classic does self adjust the Absorb time once the ending amps is set up correctly. The Absorb will end when the battery is full if that is 1 hour or 3 hours  as needed . But the Absorb time must be set long enough time and then will act more as a safety.

There is no other way that the Classic would be able to determine the correct amount of Absorb time automatically and the Whizbang was a great feature that was added  to enable exactly what you are talking about.

But first you need to determine the exact ending amps for your batteries.

Larry

[Westbranch]

For Example...  if you set the EA value to 0.1A and there is lots of sun ( 6 hours+) with 3hrs time for Absorb....  the Classic will stay in Absorb for 3 hours and then terminate and enter Float as said before...  In the winter, with 3 hrs Absorb and  EA set to 0.1A there is hardly enough sun in the North that you may not even get to Absorb let alone get 3 hrs absorb...

the objective here is to get as much Absorb as needed... your low SG and SoC says that the Absorb is too short.. or the V Absorb setting is not high enough...

When the curve of your Amps Into the battery levels off , that points is the value to use  for EA +-

I believe I read that your batteries are new, if so did the Rep tell you about the break-in period?
For most brands this is ~ 50 full cycles... that can have an effect on your ability to get the SG up...