New User - Having a little trouble understanding the Classic 150...

[Vic]

Hi Larry,

Great work on getting the BMS data graphed.   Looks very nice,  we can all learn from the work that you are doing.

73, and, have more more battery fun!  Vic

[ClassicCrazy]

Larry, so you have gotten an  ESP32 to work ?   

I have some of these but I hear from everybody that they do NOT work ?

I always wondered how they could sell so many of these if they did not work ?

boB

Yes Bob , it is using an Esp32 to get that battery data - four wires connect to esp32 pins  , 3.3v , ground,  tx, rx  . Those go to RS485 to ttl converter board which then connect A and B to RS485 jack on the battery. The wifi on the esp32 connects to my router .
I have esp8266 and esp32's running stuff around here like my energy ac and dc energy monitors , and I have another one with some one wire temperature sensors on them. They work great . If you use the Tasmota project , you just flash their firmware and they are all ready to support lots of different kind of sensors and devices . The webpage showing data is built in , so you just connect to them and see data. But they also let you easily configure to send the data out as mqtt to a broker. So that is what I do - send it to my raspberry pi running mosquito broker , and then that gets the data to the graphana software also running on the pi. It has all been running very stable for a long time.
So to answer you question they do work , but I can see why someone said they didn't work. When I first started messing around with them it was more a pain , but with the Tasmota flashed in them it makes everything very easy to do.
The one that I am using for the battery is more of a custom firmware code that Graham put together. He said he just adapted the esp project that he had for the Classic from modbus tcp to rtu .  Though I think he has done a bit more tinkering with it . But worked for me first try.
I am trying to learn how to use VS Code with PlatformIO extension in it because that seems to be how everyone with github projects does this stuff these days. You can get the projects right from github and use platformio to write and debug the code and then send the revisions back. I only scratched the surface on how to make all this work, and ran into a few issues. But at least I can see the code and try to understand how it all works.
Oh and by the way - the Tasmota firmware is so easy to flash because you can use Chrome and go to Tasmota webpage and it will flash it on the esp32 right from there - amazingly easy. But if you want you can also flash the firmware with ArduinoIDE or the PlatformIO but there is a little bit more messing around to do.
Here is a screen shot of a Tasmota manger program running on my Pi - but not all those esp devices are active right now. 
Larry

[boB]

That s awesome, Larry ! 

Glad to hear that all these ESP32's I bought (cheap) may have a future after all !

[SunTim]

Update on addition of the WB Jr...

Installed a few days ago, everything worked exactly as described and as covered in the instructions. The design, using a single wire interface is a clever and effective method. The software is well integrated including using the yellow LED to indicate current limit and an intermittent pop up of SoC value on the main status display. Kudos on a well implemented after market addon.

I've set the current limit at 30A and am seeing a consistent charge cycle each day (93-95% SoC). If left to its own, Bulk current will vary between 20 and 60 amps based on sun. As mentioned earlier, this variation directly affects the battery terminal voltage at end of Absorb cycle. My goal is to have it complete at about 90% daily.

It'll be interesting to see how the WB Jr likes this routine of daily charging to something less than 100%. I believe it will self calibrate when a 100% SoC condition is detected, not sure whether it will interpret my transition to float as a 100% charge even though it is something less than that.

Having fun, Tim

PS Larry, thanks for sharing the serial communication developments, I'll definitely be following your lead, somewhere down the road.

[boB]

Beautiful mounting job, SunTim !   THAT's the way it's done !

Yes, I really liked the one-wire power and bi-directional method.

Well, it's really TWO wires including the negative cable but don't tell anybody !

boB

[SunTim]

Hi All,

Back again with a few more questions about the Classic 150 CC.

I have been trying to get consistent daily charging performance at a predictable charge around 90%

My current  settings are...
Absorb 55.8V at 3 minutes
Float at 53.6
Battery current limit at 30A via WBjr
Classic 150 voltage calibration set at +0.3V (based on battery measurements with DVM)

My results...
In general, I get a daily charge in the 92-97 % range.
Some days, however, things go to float too early resulting in charge anywhere from 75 - 90%.

Today I was able to watch this early absorb-float situation.
CC displayed voltage was fluttering in the 55.1 to 55.4 range. (Absorb set at 55.8 V)
Mode display started jumping between Bulk MPPT and Absorb for about 3 or 4 minutes.
At only one point during the mode toggling, I saw voltage quickly jump to 55.8, at the same time the internal fan shut off.
Then CC went to float.
The charge was at about 90% (as reported by Kilovault battery app)

So, I forced back to Bulk mode by raising ReBulk setpoint to 54V. This worked fine, but within about 5 minutes the above events just happened again.

Tried a second ReBulk, same result again.

So, it looks like we are determined to get to absorb even though the displayed voltage is not there yet.


Questions...
1) Can battery voltage jitter enough to be triggering Absorb even though the displayed voltage is about 0.5V shy?

2) Does the Classic have any filtering settings to slow the reaction to transient voltages.

3) Is it normal for mode to toggle back and forth between Absorb and Bulk MPPT?

4) Is there any quick way to return from Float to Bulk without having to change the ReBulk setpoint.

5) Has anyone tried putting a scope on the battery voltage to see how it behaves? I will probably give this a try, but I'll need round up an isolation transformer for the scope first. I wonder if battery BMS operation can cause voltage to fluctuate quickly.

Thanks for the support!
Tim

[boB]

Hi All,

Back again with a few more questions about the Classic 150 CC.

I have been trying to get consistent daily charging performance at a predictable charge around 90%

My current  settings are...
Absorb 55.8V at 3 minutes
Float at 53.6
Battery current limit at 30A via WBjr
Classic 150 voltage calibration set at +0.3V (based on battery measurements with DVM)

My results...
In general, I get a daily charge in the 92-97 % range.
Some days, however, things go to float too early resulting in charge anywhere from 75 - 90%.

Today I was able to watch this early absorb-float situation.
CC displayed voltage was fluttering in the 55.1 to 55.4 range. (Absorb set at 55.8 V)
Mode display started jumping between Bulk MPPT and Absorb for about 3 or 4 minutes.
At only one point during the mode toggling, I saw voltage quickly jump to 55.8, at the same time the internal fan shut off.
Then CC went to float.
The charge was at about 90% (as reported by Kilovault battery app)

So, I forced back to Bulk mode by raising ReBulk setpoint to 54V. This worked fine, but within about 5 minutes the above events just happened again.

Tried a second ReBulk, same result again.

So, it looks like we are determined to get to absorb even though the displayed voltage is not there yet.


Questions...
1) Can battery voltage jitter enough to be triggering Absorb even though the displayed voltage is about 0.5V shy?

2) Does the Classic have any filtering settings to slow the reaction to transient voltages.

3) Is it normal for mode to toggle back and forth between Absorb and Bulk MPPT?

4) Is there any quick way to return from Float to Bulk without having to change the ReBulk setpoint.

5) Has anyone tried putting a scope on the battery voltage to see how it behaves? I will probably give this a try, but I'll need round up an isolation transformer for the scope first. I wonder if battery BMS operation can cause voltage to fluctuate quickly.

Thanks for the support!
Tim

  Hi Tim...

  It is somewhat normal to see going from Absorb to Buk and back and forth but not always.

  Do you have Ending Amps set to greater than zero amps ?  (0A = Disabled)

  The voltage below Absorb that the Classic can go down to and still count down the Absorb time is about -0.3V so -0.5 0r -0.4V should not be allowed.

  We are working on changing this to be less value for lithium batteries though.

  I would think that if there was a BMS issue where it makes the Classic go UP in voltage, it would go higher than what you were seeing.

   I don't suppose you have any battery temperature compensation enabled in the Classic since you are using lithium ?  Is there a temp sensor plugged in ?

  What is your battery charge efficiency set to ?  Should be near 100% or a few % below that.

  If you are able to get a video of the MNGP screen, that might help see what is going on.

  boB

[Vic]

Hi Tim,

There is the ability to force the Classic, into doing a new Bulk, or force it into Float:

Tweaks > More, and Right Arrow over about three selections, and up arrow ...  I forget,  the exact position of these two items.

Toward the back of the Classic Manual,  there is a very complete Menu Map that will show these Deluxe Menu options.

To me,  the Classic has, by far the most comprehensive number of actions that the Classic will perform,  often available from the MNGP,  or from the MN Locat app.  Forcing a new Bulk,  or Float is available in the local app.

Vic

[ClassicCrazy]

Did you tweak the Classic voltage for the high part of the charge ?
Larry

[SunTim]

Hi all, thanks for the responses, you guys are great!

from boB's post...
  Do you have Ending Amps set to greater than zero amps ?  (0A = Disabled)
>> Hi boB, thanks! Ending amps currently set to 2.0 Amps. It seems that current stays close to around the 30 A current limit value, so I suspect the End Amps should not be coming into the picture.

   I don't suppose you have any battery temperature compensation enabled in the Classic since you are using lithium ?  Is there a temp sensor plugged in ?
>> No sensor connected

  What is your battery charge efficiency set to ?  Should be near 100% or a few % below that.
>> Set at 94%. Can you tell me what effect this could have.

  If you are able to get a video of the MNGP screen, that might help see what is going on.
>>I'll take a look at doing that. I'll need to research how I'd upload a video.


from Vic's post...
There is the ability to force the Classic, into doing a new Bulk, or force it into Float:
>> Thanks Vic, I had not discovered that menu feature, I'll try it next time.

from Larry's post...
Did you tweak the Classic voltage for the high part of the charge ?
>> Hi Larry, I calibrated battery voltage offset during a low amps 'Float' period.
Interesting point, though, as I think I have observed an increasing offset error as the battery reaches full charge. Makes me wonder if any correction or compensation is built into the displayed voltage.

I wonder if the moonscope display would have any benefit here. What data and scaling does it display. It is probably not fast enough though, I know how quickly those features can eat up all your resources!

Thanks again for the help. I'm going to see about putting my scope across the battery to see just what's going on with voltage. If I'm successful I'll post an update.

Tim

[boB]

If you are using lithium, the charging efficiency is closer to 100%.  Like, 98% I hear a lot.

If your charge is finishing at around 90%,  I was just thinking that raising the efficiency a bit would better reflect the state of charge of your batteries.

Not sure but maybe ?  That is, if you were expecting them to be higher SOC ?

boB

[ClassicCrazy]

I just had the same thing happen with my batteries and Classic.
The Classic went to Float before it reached it's absorb setpoint.
I need to double check some things like the tweaks but I don't have temp compensation enabled or ending amps set.
I had Absorb setpoint set for 55.2v .
But I have the pv input tweaked up quite a bit at 4v . I wonder if that has something to do with it.
I am going to reconfigure the pv again to be 3 series instead of 2 series .
You can see in the graph below where I forced ti back to absorb and after a bit it dropped back to float.
My batteries were only at around 85%
Larry

update - reconfigured pv so input voltage is higher- started forced absorb cycle again and now it has been staying on bulk - will see how that goes when it gets closer to absorb setpoint.

[boB]

I just had the same thing happen with my batteries and Classic.
The Classic went to Float before it reached it's absorb setpoint.
I need to double check some things like the tweaks but I don't have temp compensation enabled or ending amps set.
I had Absorb setpoint set for 55.2v .
But I have the pv input tweaked up quite a bit at 4v . I wonder if that has something to do with it.
I am going to reconfigure the pv again to be 3 series instead of 2 series .
You can see in the graph below where I forced ti back to absorb and after a bit it dropped back to float.
My batteries were only at around 85%
Larry

update - reconfigured pv so input voltage is higher- started forced absorb cycle again and now it has been staying on bulk - will see how that goes when it gets closer to absorb setpoint.

I'm sure that it did reach the Absorb voltage but that data log did not catch it since it can't log all the time...  It must have ?

Could part of it be the battery temperature compensation reducing the voltage ?

How long is the Absorb time set for ?  Have you checked the target voltage in the CHARGE menu ?

[ClassicCrazy]

Bob
after I reconfigured my PV , the only thing I changed was to take the Tweak voltage adjust for PV back to zero.
I forced it into Bulk using Local Status app and it started charging and kept charging .
I had 15 minutes on the absorb initially so should have been enough time to spot the absorb voltage I would think.
It never did get to the absorb setting after I changed the PV to 3s but got the batteries 99% to 100% full. I had some loads on it too and am loosing light on the pv now .
So tomorrow if the sun is out again I will be around and can watch it better.
The temperature compensated target voltage is the same as the setpoint when I just checked.
It was cold in the room so if anything I would have thought the temp compensation would have raised the target voltage instead of lowering it.
I will look again tomorrow and see if target voltage changes.
Larry

[ClassicCrazy]

I actually had the Classic Target voltage reporting to my graph and was able to go back and look at it. It never changed it's target voltage until it went to float and then used the float setpoint as target voltage.