Hi all, a couple of questions re: the attached image.
(//)
So last night I had to run the AC for the 1st time since I installed my 1900w PV/24v 690ah system and I woke up to 47 SOC (not great, I know). So today, also for the 1st time, I was fully expecting to see the majestic powers of my Classic 150 juicing my battery, but the most output amperage I've seen is 65~.
When I isolate my panels from the Classic I'm getting 84v @ combiner (VOC 44.6). After tying the Classic back in and on a restart I get 77v from Classic screen, but then it drops down to the 65~ shown in the attachment. So the Classic is throttling back available voltage. If it instead applied accurate voltage to current available of 28.4a it should be feeding 90.7 amps to battery, but it's not even close.
Could someone explain why? If this Classic has a max output of 98A why am I not seeing that today?
there is something not right here you should NOT be in EQ with only 72%... something is not set correctly, you should only EQ once 100% SoC has been reached.... that said your 1762W is a blazing ~93% of the PV rating you posted it should normally be ~ 72% so I don't know if those are NOTC # or not since you did not post all the panels details...
Not sure but is your max V set to 27.1 V for an EQ or the global max V? ....
1762W / 27.1V = ~64.4 amps into the battery which is what you are getting...
Tell us the details of your battery and Classic settings, that way we don't have to guess... :)
Yes - it would be helpful to know all your settings ,PV and batteries specs and configurations , etc.
Like Westbranch said - something isn't set right if it is in Equalize at that voltage and SOC.
Larry
VOC is Voltage Open Circuit which is what you are measuring when you check the voltage at the combiner with the charge controller off. The Voltage maximum power (Vmp) will be lower than VOC. The Classic 150 is going to run things closer to the Vmp because it is tracking the maximum power point. As Westbranch says, 1762 watts out of 1900 watts of PV panel is pretty good.
But double check all of the settings in your Classic 150.
With 1900 watts of PV panel and a nominal 24 volt battery bank, you will never hit the Classic 150 maximum of 98 amps. If the Classic 150 is charging the batteries at 27 volts, you would need 2646 watts of PV panel input to get to 98 amps.
Thanks for the replies.
That EQ reference is just the Classic. I have EQ set to auto and I guess yesterday was the 28th day, but EQ was never hit, nor was absorb. I got to 91% SOC before the sun vanished.
All settings (attached) have been confirmed by Deca.
As far as PV output being at 93%, I agree but have noticed that these Topoints have often exceeded their ratings. I would think their true output is as tested with voltmeter and that's 40~v. If yesterday I test at combiner and get 84~ volts, and Classic indicates it's receiving 28.4a, that should mean that in yesterday's environment my array was outputting 2400~ W, no?
Why is the Classic throttling the array's voltage down?
Edit: Panel ratings (PDF) http://sepbatteries.com/media/add_info/Topoint_JTM%20190w_mono-min.pdf (http://sepbatteries.com/media/add_info/Topoint_JTM%20190w_mono-min.pdf)
Quote from: keithwhare on May 29, 2017, 08:17:24 AM
VOC is Voltage Open Circuit which is what you are measuring when you check the voltage at the combiner with the charge controller off. The Voltage maximum power (Vmp) will be lower than VOC. The Classic 150 is going to run things closer to the Vmp because it is tracking the maximum power point. As Westbranch says, 1762 watts out of 1900 watts of PV panel is pretty good.
But double check all of the settings in your Classic 150.
With 1900 watts of PV panel and a nominal 24 volt battery bank, you will never hit the Classic 150 maximum of 98 amps. If the Classic 150 is charging the batteries at 27 volts, you would need 2646 watts of PV panel input to get to 98 amps.
Thanks for that. So you're saying that even though my panels are consistently outputting VOC (is that normal?), the Classic's logic is to tone that down. Makes sense, I guess, but how does Classic know my VOC and VMP if they're not settings I input? Does it just automatically reduce any array's voltage 20%?
Edit: Thinking more about that, it has only been recent that the Classic has throttled my array's voltage down like this. A few weeks ago it was consistently 75~v. I thought that was because it's been heating up around here so PV voltage dropped, but yesterday my voltmeter indicated that was not the case. So in a matter of weeks, Classic has throttled my input voltage from 75~v down to 65~v (presently at 68.2v)
If I take a typical wall wart cube that you plug into power something it may say 9 volts but if I measure the voltage it may show 12 volts. But as soon as you put a load on it and measure the voltage with the load it drops down to closer to what the rating is.
Pretty much the same deal with the PV - unloaded you get the open circuit voltage but when you connect the battery the voltage is going to drop . It still has to be higher voltage than the battery to force any amps into it .
So when you check your Voc you can also check the Isc ( think that is what it is called ) current short circuit. You take the positive and negative wires from a panel and short them together and check the current . Of course you don't want to do this with a whole array because it is too high voltage and can arc. But one panel at a time and if you have a clamp on DC amp meter you will see the current potential of that panel at that time of day .
If you look up MPPT there are plenty of explanations of how they work to get more power out of the panels than typical PWM controller
Are you using ending amps to stop absorb or just time ?
There are so many considerations to a system - voltage drop of wiring, connectors, and breakers or fusing, etc. Hard to diagnose a system without seeing or details of the whole thing. For example - how many batteries are in series and series parallel ?
Larry
Quote from: ClassicCrazy on May 29, 2017, 10:50:24 AM
If I take a typical wall wart cube that you plug into power something it may say 9 volts but if I measure the voltage it may show 12 volts. But as soon as you put a load on it and measure the voltage with the load it drops down to closer to what the rating is.
Pretty much the same deal with the PV - unloaded you get the open circuit voltage but when you connect the battery the voltage is going to drop . It still has to be higher voltage than the battery to force any amps into it .
So when you check your Voc you can also check the Isc ( think that is what it is called ) current short circuit. You take the positive and negative wires from a panel and short them together and check the current . Of course you don't want to do this with a whole array because it is too high voltage and can arc. But one panel at a time and if you have a clamp on DC amp meter you will see the current potential of that panel at that time of day .
If you look up MPPT there are plenty of explanations of how they work to get more power out of the panels than typical PWM controller
Are you using ending amps to stop absorb or just time ?
There are so many considerations to a system - voltage drop of wiring, connectors, and breakers or fusing, etc. Hard to diagnose a system without seeing or details of the whole thing. For example - how many batteries are in series and series parallel ?
Larry
There you go. Great explanation that I should have realized.
So I assume I'll see input voltage displayed rise once EQ is finished and in float.
Quote
"Are you using ending amps to stop absorb or just time ? "
Yes, I'm not certain of all the settings but I have ending amps set at 5. I had absorb at 3 hours on Deca's recommendation but changed it to 2 hours after noticing a bit too much water escaping batteries.
Quote
"how many batteries are in series and series parallel"
https://www.youtube.com/watch?v=8YDiAO9W-Qc (https://www.youtube.com/watch?v=8YDiAO9W-Qc)
From the diagram of your system, it looks like you are using Top Point JTM190-72M PV panels. The data sheet I found lists the following characteristics:
Vmp: 36.5
Imp: 5.20
VOC: 43.8
ISC: 5.83
The VOC of 44.6 that you quoted in your original post is from the Top Point JTM195-72M PV panels, which have the following characteristics:
Vmp: 37.2
Imp: 5.24
VOC: 44.6
ISC: 5.88
In any case, the important number is Watts, not Volts.
Under standard test conditions, the panels will produce 190 watts per panel at 36.5 volts and 5.2 amps. Standard Test Conditions (STC) are 1000 watts of sunlight per square meter. Real life almost never matches standard test conditions.
Hi RobertA,
First, regarding calculating the power that the PV array is producing at any one time, you must use the actual String Vmp (the Max Power Point that the Classic has found, in its most-recent Sweep). The voltage that you have measured at the combiner often has no relation, at all, to the Vmp that the Classic has found for the conditions of PV Cell temperature, and irradiance ( the effective Solar intensity), from the last Sweep.
The Classic has a very accurate current Shunt to read the Classic's OUTPUT current, and also has an accurate voltage meter.
The temperature of the PV solar cells has a large impact on the output voltage, and this results in a fairly large reduction in the PV power available. This is primarily due to the heating of the PV cells by the sun.
Typically we use a rule-of-thumb, that for a typical day, the PV power production will be about 75% of the STC power rating of the PV, at solar maximum, with the PVs oriented at right angles to the sun. But, on cool/cold days, especially with considerable wind, the Vmp of PVs can exceed STC Vmp ratings. This can cause the PVs to exceed STC output power ratings.
The STC ratings of PVs are measured values, using a Flash Tube for illumination of the PV Module, with the Cell temperature held at 25C. The Flash Tube creates no real heating of the PV. This is one of the main reasons that we typically do not see STC power outputs from PVs in most applications.
It is a good idea to EQ Flooded batteries after they have been fully-charged, or, very close to it. For generally unattended systems, Auto EQ can be good, but if possible, Manually starting and monitoring the EQ process might be better.
YES, when the Classic is in a charge stage where it is regulating the battery voltage (Absorb, Float, and EQ and not showing -MPPT) you should see the Vin to the Classic rise. The lighter the load on the system, compared to the amount of PV power available, the relatively higher will be the Vin to the Classic.
FWIW, Vic
As told to expect, voltage did climb once float mode was achieved. That's good!
I did make another observation today that I'm not too thrilled about. I think the Classic's logic should be re-written to respect the Whiz-bang better. For example, because of the depleted state of my battery yesterday (47 SOC) it took 1.5 days to fully charge, but I had to restart the Classic in order for it to get there, otherwise it would have moved to float mode and left my battery undercharged. I think it should have instead realized, thru Whiz-bang, that I wasn't fully charged and continued in absorb mode until battery hit full capacity.
Sure, I could increase absorb time again but I'd rather not fry battery, not should it be necessary. Classic should change modes based on Whiz-bang amp stat, I think.
Hi RobertA,
There may be one (or more) settings in the Classic that you may need:
There is the Auto Reset function, that when is set to ON, begins a new day at 23:59, each day, and "ReBoots" the Classic. Most of us run Classics with ARST = ON.
You might want to check in the Tweaks menu, to see if " ARST " is set to ON.
Without ARST enabled, the Classic will begin the each day in Float-MPPT, and avoid fully recharging the battery each day, UNLESS you have set ' Skip Days ' to some value other than ' 0 '.
If I understand what you are saying about what was happening today ...
Vic
Well, kinda, except I think its behavior on restart is actually the opposite. If the sun is up, it will always start in absorb mode and for the time period configured. I know this because I've had to restart in the past to top battery off, and had to do so again today. Whatever the case, my point is that it should instead read the Whiz-bang data and, even on restart, jump to the mode reflective of amperage readings. Just because I have absorb set for 2 hours shouldn't mean Classic moves to float after 2 hours even if my battery is only 80% charged. That needs to be addressed.
If you only have 2 hours for Absorb time and the batteries need 3 or 4 hours then it would take multiple days to fill up the batteries. That is why ending amps when done correctly is a better way to go . But to set it up with flooded batteries you need to watch the amps and find the point where they start to taper off as the SOC comes to 100% and confirm that with Specific Gravity readings of the electrolyte. Then when you are pretty sure you have the correct ending amps you set the absorb time up to 4 or 5 hours and let the ending amps setting take it from absorb to float.
Not sure what you meant that the voltage climbed when it was in float - the voltage should climb in Bulk to the Absorb setpoint , then hold it at the Absorb voltage and the Classic will cut the current back to maintain that . When it gets to either ending amps or absorb time which ever comes first then it will go to Float and the voltage will stay in Float unless you put on some huge load to draw it down above what current the panels are providing.
Also make sure you have your temperature compensation values set - that will change the setpoints higher or lower as needed according to the battery temperature via the external temperature probe you have on them.
Larry
I have ending amps set at 5 but I thought the Classic overrides that setting in favor of Whiz-bang?
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.
Quote from: RobertA on May 29, 2017, 09:36:19 PM
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
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
Quote from: ClassicCrazy on May 29, 2017, 10:22:10 PM
Quote from: RobertA on May 29, 2017, 09:36:19 PM
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.
Quote from: ClassicCrazy on May 29, 2017, 10:33:17 PM
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.
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
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!
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
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.
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
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
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?
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
Quote from: RobertA on May 30, 2017, 09:05:49 AM
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
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...
Hi Robert,
Thanks for confirming that ARST is ON, and NO Skip Days.
The main reason for asking those two questions, was that you mentioned that on the "second" day after the deeper discharge, that the Classic was not charging the battery (IIRC, you said that it began in Float). ARST being OFF can cause that.
Should have asked, what version of Firmware are you running in the Classic, and MNGP?
IMO, try to keep in mind:
1. Flooded batteries are rugged, and quite tolerant of overcharging (much better than when they are chronically undercharged)
2. Battery SOC monitoring devices, really only give a rough approximation of actual SOC.
3. The Gold Standard of actual SOC on Flooded batteries (FLAs) is to use a good quality Hydrometer.
4. As has been stated before, EA is generally a very good way to terminate Absorb when the batteries have received a sufficient charge. As you know, the time required for Absorb varies relatively directly with the Depth Of Discharge of the battery, in the previous discharge.
5. Some water consumption is good for FLAs. The difference between some and excessive, is of course, a grey area.
In summary, you can choose several Pilot Cells (usually cells that have the lowest SG, compared to others in THAT string of batteries). These cells will give a quick read on actual SGs, and can be used to adjust charge parameters. Each string of batteries needs at least one Pilot. It will still be a good idea to measure the SGs of each cell in the bank every month or two, after things stabilize with the bank. Be certain to thoroughly RINSE the Hydrometer with Distilled Water three or more times after each measuring session.
You will want to mark each battery and cell with a number, and letter (usually), and enter in your Battery Logbook, all the SG info, charge parameters, EQ date, duration, and voltage, date the bank was watered, and, at least the total quantity of Distilled Water that was added, etc.
Just some opinions. Vic
Ok, all, I guess a setting is off, after all.
The reason I thought Classic ignored Whizbang was because I would consistently see SOC at 100% and the Classic still pushing absorb mode. That's what I'm seeing now too but if I look at (phone app) 'Messages', I have ending amps set at 3.0a, and the system is indicating "(currently at 8.1 A)". So I guess I've never had ending amps properly set?
SOC: 100%
Battery Current: 7.8 A
Consumption: 7A
Capacity: 700 total, 700 remaining
I keep looking at Messages, Ending Amps and it just sits between 7.8-8.1
So, what's up? Deca indicates my ending amps should be 1.5% of AH/20 rating, which is around 3.
Robert,
If your batteries are not being fully charged, when using EA, why not set EA to 0, for now, until you are able to fully charge the batteries.
You can set the Absorb time fairly long, and watch the WBjr current into the batteries. At some point, that current will taper, with a very low rate-of-change in the WB current. It is in that region, where the best EA resides.
The correct EA for those batteries will change as they cycle (as Westbranch noted), and with the Absorb voltage (Vabs), and as the batteries age. But, still, it seems to be well worth the effort to get the EA dialed in.
Measuring SGs will be your primary indicator of how well the batteries are being charged.
BTW, here is a Link to Surrette Battery's article on measuring SGs. This is a good summary, for most any Flooded batteries:
http://support.rollsbattery.com/support/solutions/articles/4347-measuring-specific-gravity
EDIT: Also, the EA settings for the FLAs here had been about 0.9% of 20-hour Capacity. In the past several years, the Vabs needed to be increased by about 0.4 V (on 48 V banks), and this (probably among other things), necessitated increasing the EA up to about 1.5 % of C.
FWIW, Vic
Good question; why can't I set it to 0?
Answer: It would never get there.
UPDATE:
So I changed ending amps to 8, saved and restarted. On system start ending amps jumped to 11.7, which means it didn't read the Whizbang logs as SOC was still 100%. Because it started at 11.7 it went back into absorb mode (as it always does on restart). Over a period of 5-7 minutes it slowly worked itself back down to 7.8 again and did, in fact, change to Float mode. And you know what? that consistent 7.8-8.1 ending amps reading then dropped to 2.1.
Very bizarre stuff that begs the question: OK, what the heck is ending amps than? Because it dropped when Classic went into Float mode it must have to do with output amperage, but why did that output amperage never drop even though Whizbang indicated that SOC was at 100%?
UPDATE 2: I recorded it this time: https://youtu.be/_ZdSnGBMtXY (https://youtu.be/_ZdSnGBMtXY)
Quote from: RobertA on May 30, 2017, 05:09:50 PM
Good question; why can't I set it to 0?
Answer: It would never get there ...
... Very bizarre stuff that begs the question: OK, what the heck is ending amps than? Because it dropped when Classic went into Float mode it must have to do with output amperage, but why did that output amperage never drop even though Whizbang indicated that SOC was at 100%?
UPDATE 2: I recorded it this time: https://youtu.be/_ZdSnGBMtXY (https://youtu.be/_ZdSnGBMtXY)
Robert, Do not know what you are saying when you mentioned, "Good question; why can't I set it to 0?
Answer: It would never get there ..."
My Classic can be set to 0. The reason that I suggested setting it to 0, was, so the full Absorb time that had been set would be used, and the Classic would not use an EA, because it was set to zero.
What is EA? It is the Finishing Current (Ending Amps), that is going into the batteries, as measured by the WBjr on the Shunt.
If the voltage applied to the battery by the CC is reduced, then this current into the battery is reduced. This IS what happens on the transition to Float, as Vflt is customarily set below the Vabs, or Veq.
If one feels that a higher Vabs is needed, then the Finishing Current will often need to be increased, as this voltage increase will increase the current flowing into the battery.
#### What version of Classic and MNGP Firmware are you using? ####
Thanks, Vic
Firmware:
- Classic Rev: 2126
- Network Rev: 2097
Quote from: RobertA on May 30, 2017, 05:09:50 PM
Good question; why can't I set it to 0?
Answer: It would never get there.
UPDATE:
So I changed ending amps to 8, saved and restarted. On system start ending amps jumped to 11.7, which means it didn't read the Whizbang logs as SOC was still 100%. Because it started at 11.7 it went back into absorb mode (as it always does on restart). Over a period of 5-7 minutes it slowly worked itself back down to 7.8 again and did, in fact, change to Float mode. And you know what? that consistent 7.8-8.1 ending amps reading then dropped to 2.1.
Very bizarre stuff that begs the question: OK, what the heck is ending amps than? Because it dropped when Classic went into Float mode it must have to do with output amperage, but why did that output amperage never drop even though Whizbang indicated that SOC was at 100%?
UPDATE 2: I recorded it this time: https://youtu.be/_ZdSnGBMtXY (https://youtu.be/_ZdSnGBMtXY)
Robert ,
Maybe we are not all on the same page .
Here is what happens and happened in your video.
It starts out below the Absorb setpoint and that is Bulk
When voltage climbs to Absorb voltage setpoint it changes to Absorb mode
It will stay in Absorb holding the Absorb voltage setpoint but decreasing the current.
How long will it stay in Absorb ?
Either for Absorb time
or
if you have these things done
Config / Tech/ Ending amps ( whatever number you have in there ) and check box for Use WBJR for Ending amps
Just for example
You have Absorb voltage 28.8 v and Absorb time 2 hours
and Ending Amps is set for 0 ( on that config menu
Then you would see it go from Bulk to Absorb when voltage gets to 28.8
and it will stay in Absorb at 28.8v for 2 hours
The current ( system amps ) will decrease during that time but voltage stays the same
at end of 2 hours Then it will go to Float voltage and hold that voltage for the rest of the day as long as there is sunlight to do that
Second example
You have Absorb voltage 28.8 v and Absorb time 2 hours
and Ending Amps is set for 5 ( on that config menu )
Then you would see it go from Bulk to Absorb when voltage gets to 28.8
and it will stay in Absorb at 28.8v
The current will decrease during that time but voltage stays the same
When the current ( system amps) gets to 5
it will go to Float
But only if it does that in less than 2 hours
So in this case if it never got to 5 amps in 2 hours that would mean the Absorb time of 2 hours was too short.
Does this make sense ?
Those were just made up numbers for examples. Like Vic said you need to find ending amps by setting ending amps to zero ( set absorb time longer like 3 or 4 hours ) then watching for the current - system amps - to level off and this should be about the same time you would see the specific gravity getting to 1.265 ( forget if that is the right number for 100% charge )
So when you find this system amps and specific gravity reading that will be your ending amps to put in
Config / Tech/ Ending amps ( whatever number you have in there ) and check Use WBJR for Ending amps
In your video I was hoping you would have gone through all your Config screens so we could see what everything is set for. In the video you mentioned 8 and I did not know what you were referring to .
Larry
Makes perfect sense, i don't doubt for a second that that's what it's doing.
What I'm saying though is that if Classic followed the Whizbang, it would boot up, recognize SOC is at 100%, and then immediately go into float mode. That should be the case in every other scenario too. If SOC is at 100% Classic should not be boiling my battery with amps, regardless if some here think that's perfectly fine.
Quote from: RobertA on May 31, 2017, 08:57:11 AM
Makes perfect sense, i don't doubt for a second that that's what it's doing.
What I'm saying though is that if Classic followed the Whizbang, it would boot up, recognize SOC is at 100%, and then immediately go into float mode. That should be the case in every other scenario too. If SOC is at 100% Classic should not be boiling my battery with amps, regardless if some here think that's perfectly fine.
Bubbling electrolyte is a natural function of lead acid battery charging - it is going to happen every day.
As Vic and others have said - the SOC is just an estimate so the Classic can not use that to control charging.
If you have the ending amps set correctly it will terminate the Absorb charging cycle and go to Float sooner than if you have it set to just use Absorb time - ( unless the batteries are really low ) .
The Classic does follow the Whizbang when in Ending Amps mode - it is monitoring the system amps ( what is going into the batteries).
I think that is the extent to how I can explain how it works !
Larry
Quote from: RobertA on May 31, 2017, 08:57:11 AM
... What I'm saying though is that if Classic followed the Whizbang, it would boot up, recognize SOC is at 100%, and then immediately go into float mode ...
Hi Robert,
Again, the SOC reading from any Battery Monitoring device is not particularly accurate. If we have the Vabs, EA and Vflt set accurately for our batteries, the most accurate SOC reading from the WB will be when the Classic makes its own transition from Absorb to Float (this is when the WB/Classic reset the SOC to 100%).
There are many reason for the inaccuracies in SOC monitoring devices. One of the largest of them is the Remaining Capacity of Flooded batteries depends to a large extent upon the Rate at which AH are removed from the battery (discharge current). Most battery monitors do not account for this variable rate, AND attempting to create a good model of this variable, for any particular battery is quite involved, and affected by other variables.
There is a (IMO) much better approach to determine when to end battery charging -- setting a nominally correct Vabs, and using EA to terminate Absorb (and having the Absorb time set long enough for almost any recharge scenario).
The above is not exactly what you appear to want to have happen.
I have not ever seen you state just what is the reason that you have this power system. Is it a Backup to Grid power, is it 100% off-grid, etc ?? ? Seems that you expect that there will be a reasonable chance that your batteries will begin days at 100% SOC. If there were NO loads on the batteries during the night, there will be some amount of self-discharge during the night. In some number of days, this self discharge will need to be accommodated by a battery charge cycle. Certainly, with only an inverter running during the night hours, this idle current consumption will need cause the batteries to need recharging every day or so ...
If your system has little or no loads on it, you might wish to consider Skipping Days of battery charging.
Have not looked at the first Video that you posted, but, it would be very convenient for those trying to help you, if you created a Signature that details the type of system you have (Grid Backup, Off-Grid, etc), the system hardware and the battery Capacity, manufacturer and model number, etc. This will allow more effective advice, without you being asked time and time again for the details of the system.
Many of us would like to see functions added to the Classic and WBjr, but having perfect SOC readings are simply not close to being a reality, due primarily to the nature and behavior of Flooded batteries in varying discharge and charge conditions.
My opinions, Vic
Good post, Vic (you too CC), especially about amperage draw rate.
My system is a hybrid. I can be fully off-grid, as I have been for months now, or, as long as I'm at a location with grid power, I can connect to that instead. With AC becoming mandatory soon, I suspect I'll be using the latter more than I'd wish. We'll see though. It's an RV https://www.youtube.com/watch?v=G6gXr-GAuBs (https://www.youtube.com/watch?v=G6gXr-GAuBs)
Boiling batteries aside, I'm going to take a few suggestions from this thread and see if they help. I have new Deca voltages to consider and an understanding that Classic will jump into float automatically (which I didn't see evidence of before). The first thing I've done adjusted battery voltages and set ending amps at 1A, and I have absorb timer at 8 hours. I will monitor SG throughout day and try to determine correlation with ending amps.
Quote from: RobertA on May 31, 2017, 12:12:27 PM
Good post, Vic (you too CC), especially about amperage draw rate.
My system is a hybrid. I can be fully off-grid, as I have been for months now, or, as long as I'm at a location with grid power, I can connect to that instead. With AC becoming mandatory soon, I suspect I'll be using the latter more than I'd wish. We'll see though. It's an RV https://www.youtube.com/watch?v=G6gXr-GAuBs (https://www.youtube.com/watch?v=G6gXr-GAuBs)
Boiling batteries aside, I'm going to take a few suggestions from this thread and see if they help. I have new Deca voltages to consider and an understanding that Classic will jump into float automatically (which I didn't see evidence of before). The first thing I've done adjusted battery voltages and set ending amps at 1A, and I have absorb timer at 8 hours. I will monitor SG throughout day and try to determine correlation with ending amps.
What you are looking for is watch when it goes into Absorb - note the system amps and keep watching the amps when the SG starts to get up to full charge . The system amps at first will keep dropping but around when the specific gravity is showing full charge you should notice the system amps is not dropping so fast - it will be sort of holding steady for longer period of time . This is the number that your Ending Amps would be.
But you should run a good load on the batteries the night before so that it will make it easier to spot this transition.
Do you have ability to use MyMidnite - needs internet connection ? I find that is a good way to look back at the day of charging because it graphs the curves and state of charge so it makes it easier to spot that system amps leveling off .
If you are good with data you can also use the Local Status app data collection and download it to Excel and make a graph . But you will have to look up in past forums how to do that - I have messed with it but am not well versed enough with Excel to tell you how to do it ( or myself for that matter) . But if you don't know how maybe you can hire a local geek kid who does to chart out the data for you!
Larry
Hi Robert,
First, great work on modifying the RV to accommodate your power system!
As CC Larry mentioned, watching the WB Current (battery charge current). As the batteries become more fully charged, the WB current will taper. The rate-of-change in this current will become very small, as the proper EA value (at least for the Vabs that has been set). You will find that at the very end of the of this, the rate of change will become essentially zero. The WB current at this time will be a very good value for the EA setting in the Classic. There is some small variation in the WB current readings (jitter), but just watching the WB current on the MNGP will allow you to average the WB readings.
You can measure the SGs when the WB current approaches zero rate of change. As mentioned before, the amount of WB current that represents this zero rate of change will vary, depending upon the Vabs. If the Vabs is increased, this (essentially) zero change current change will occur at a higher current value.
Wb mentioned that new FLAs will need a number of cycles before they build Capacity to its final value. This cycling is good, and you will probably notice that some of the charge parameters, and the proper EA value may well change, as well as the AH Efficiency setting (probably).
CC Larry noted that boiling (gassing) of batteries is normal if one wants to fully charge FLAs. Gassing mixes the acid in the electrolyte, and this mixing reduces or eliminates Stratification (EQing does an even better job of mixing). Stratification is where the heavier acid sinks to the bottom of the batteries, and needs gassing to reverse this.
Recharging FLAs must involve raising the charge voltage above the Gassing voltage. This is a must. Gassing consumes water, and causes some plate erosion, but this is far better than not gassing enough, resulting in undercharge. Chronic undercharging will cause hard sulfates to build up on the plates, which is difficult or impossible to remove. Chronic undercharging of FLAs is usually the most common reason for battery failures.
There is little that is absolute about Lead Acid batteries. Many variables exist, and not all of these are always evident.
BUT, FLA batteries are quite forgiving, can take a considerable amount of overcharging. Just watch electrolyte levels, and NEVER allow the electrolyte level to go below the tops of any battery plates. This will surely ruin batteries.
Larry also mentioned the battery AH Efficiency setting for Flooded batteries. You could probably start with a setting of about 85%. Opinions differ on this. As your batteries cycle this value will probably need to change. Aging of batteries will also usually mean a change to this setting (in WBjr Setup).
Good Luck, and please let us know how you are doing.
Vic
Quote from: RobertA on May 31, 2017, 12:12:27 PM
...
With AC becoming mandatory soon, I suspect I'll be using the latter more than I'd wish. We'll see though. It's an RV https://www.youtube.com/watch?v=G6gXr-GAuBs (https://www.youtube.com/watch?v=G6gXr-GAuBs)
AC becoming mandatory for what?
Hi dgd,
Think that that AC = A/C=Air Conditioning (probably).
Alternating Current IS always mandatory!
FWIW, 73 Vic
Quote from: Vic on May 31, 2017, 09:06:49 PM
Think that that AC = A/C=Air Conditioning (probably).
Alternating Current IS always mandatory!
Phew! That's a relief, I was thinking my DC battery bank would have to be replaced with an AC bank
Thankfully I have plenty of air so conditioning it isnot an issue. Although I'm not sure how to condition the air before it hits my turbine blades. But it's an AC turbine too so that may be ok if it becomes mandatory...
Dgd
Update and question:
It was cloudy all day yesterday so I thought I'd start from scratch. I shut down Whizbang and via my 65 amp inverter/charger, I ran a 3 hour EQ at higher 31v, then a charge/float all night at standard 27.6v. My SG is now up to 1277, which is higher than I've ever seen. A great starting point.
Question: Even without the Whizbang data the Classic can determine peak SOC? I say this because Classic is no longer charging batteries (346W on a 1700w day (sunny, not so hot)), even though it's set, and active, in absorb mode. That seems pretty cool, would someone explain?
I'll now turn Whizbang back on which should exit Classic from absorb mode and set tomorrow up for EA observations.
Edit: With an obviously full battery EA has been sitting between 4-5 for almost 2 hours. 690ah*1% = 6.90 but it looks like an EA of 5 should work here.
Edit*2: After re-setting EA to 5 and rebooting, Classic jumped into float mode almost immediately. Leaving absorb time at 8hrs because I don't see any downside in doing so and, with Air Conditioner soon running all day I'll not hit float mode again until late October (eat it, northerners ;D)
Quote from: RobertA on June 01, 2017, 12:44:55 PM
Update and question:
It was cloudy all day yesterday so I thought I'd start from scratch. I shut down Whizbang and via my 65 amp inverter/charger, I ran a 3 hour EQ at higher 31v, then a charge/float all night at standard 27.6v. My SG is now up to 1277, which is higher than I've ever seen. A great starting point.
Question: Even without the Whizbang data the Classic can determine peak SOC? I say this because Classic is no longer charging batteries (346W on a 1700w day (sunny, not so hot)), even though it's set, and active, in absorb mode. That seems pretty cool, would someone explain?
I'll now turn Whizbang back on which should exit Classic from absorb mode and set tomorrow up for EA observations.
Edit: Someone asked to see my settings. Here: https://youtu.be/Auxsmqep71k (https://youtu.be/Auxsmqep71k)
Edit, Edit: With an obviously full battery EA has been sitting between 4-5 for almost 2 hours. 690ah*1% = 6.90 but it looks like an EA of 5 should work here.
Edit*3: After re-setting EA to 5 and rebooting, Classic jumped into float mode almost immediately. Leaving absorb time at 8hrs because I don't see any downside in doing so and, with Air Conditioner soon running all day I'll not hit float mode again until late October (eat it, northerners ;D)
What do you mean you shut down the Whizbang ? It is just an amp monitor .
I guess I don't understand what you are doing .
Your video link says it is not there any longer .
Larry
I turned it off so EA would not interfere. It's back on now.
Quote from: RobertA on June 02, 2017, 09:50:38 AM
I turned it off so EA would not interfere. It's back on now.
The whizbang being on or off will not interfere with anything. It just monitors the amps going in and out of the battery .
The way to turn ending amps on and off is to set it to zero and uncheck the box that say " Use WBjr for ending amps" .
But maybe that is what you mean . I am not sure if you mean you go to the Config menu for AUX 2 and disable it there ?
Larry
I realize that but didn't want to take any chances so I shut it down at AUX2. Anyway, I was able to determine proper EA which is what I sought to do.
Now to see if current settings return SG to peak level again.