What wakes up Classic to start charging ?

Started by ClassicCrazy, July 13, 2022, 11:24:25 AM

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ClassicCrazy

I just set up new 48v lithium system using a Classic.
When I first turned it on no charging started.
I messed around with a lot of settings and firmware reloads, VMM , etc waited till the next day , etc.
Absorb setpoint I have is 56v , batteries were at 52v .
I finally got charging to happen - or maybe it happened next day on one of my tinkering around with different setups.
The Classic just doesn't seem to wake up and start charging as early as I think the lead acid setup did.
This morning I got this photo just before it woke up and started charging - photo shows where it was at .
( I was poking around with MNGP at the time the relay clicked on to start charging - I was in the amps limit menu but maybe just coincidence)
Here are the screen shots of what Classic display was just before it started charging, the light level on the PV, and the PV worksheet from sizing tool.
I am wondering if the PV voltage is too close to the Absorb voltage ?
Absorb 56, Float 54, Absorb time 5 minutes for now , 15 ending amps since this is 15kwh battery.
But since this is new I haven't gotten the batteries up to 56v yet. Maybe today .
thanks
Larry
update - now it quit charging with full sun - I don't understand
See last Local Status app screenshot


system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

ClassicCrazy

Oh - I think it may have shut down because it reached 56v setpoint and that is why it is showing reason for resting 38.
I have 56v set per manufacturers recommendation for initial break in .
This shows the graph of when it shut off
So I guess all is good
Lithiums sure jump up fast in voltage when they are full !
Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

boB

Larry, the input voltage requirement in order to turn on is...

Vbatt + ((Vbatt/3)-2.0)

So, for Vbatt = 53.0 volts, the PV needs to be at least    68.7 volts.  Assuming that the readings are correct.

Now, to STAY on, that is a bit different of course.    IIRC it needs to be able to supply something like 10 or 15 watts.

boB

PS...    Reason for resting 38  means that, yes, it has reached the Absorb set point, but is at zero watts or REAL close to zero.  Usually it means that there is a second charging source  BUT  you may have found an anomaly with LFP batteries ?   That it stays up at the Absorb voltage without dropping by itself and so requires close to zero watts to stay there ?   RFR 38 also requires that the voltage is there for 90 seconds.

Does that make sense ?
K7IQ 🌛  He/She/Me

ClassicCrazy

Quote from: boB on July 14, 2022, 12:20:49 AM
Larry, the input voltage requirement in order to turn on is...

Vbatt + ((Vbatt/3)-2.0)

So, for Vbatt = 53.0 volts, the PV needs to be at least    68.7 volts.  Assuming that the readings are correct.

Now, to STAY on, that is a bit different of course.    IIRC it needs to be able to supply something like 10 or 15 watts.

boB

PS...    Reason for resting 38  means that, yes, it has reached the Absorb set point, but is at zero watts or REAL close to zero.  Usually it means that there is a second charging source  BUT  you may have found an anomaly with LFP batteries ?   That it stays up at the Absorb voltage without dropping by itself and so requires close to zero watts to stay there ?   RFR 38 also requires that the voltage is there for 90 seconds.

Does that make sense ?

I will keep an eye on it and apply the formula above.
The nice thing about having the PV so close to the Battery voltage is the Classic is running a lot cooler than my other 24v setup where I have 100v PV input.
It could be that the RFR 38 was because I didn't have much of a load on it .
There are some time delays for it to change from resting to float - when it went to float and resting  and I was messing around with the settings it can take some time to change charge states.
I am sure there is a good reason so the controller isn't hunting and clicking back and forth - like my very first solar charge controller in the 1980's that would chatter it's relay at dusk !
Thanks for the info.
Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

ClassicCrazy

Quote from: boB on July 14, 2022, 12:20:49 AM
Larry, the input voltage requirement in order to turn on is...

Vbatt + ((Vbatt/3)-2.0)

So, for Vbatt = 53.0 volts, the PV needs to be at least    68.7 volts.  Assuming that the readings are correct.

Now, to STAY on, that is a bit different of course.    IIRC it needs to be able to supply something like 10 or 15 watts.

boB

PS...    Reason for resting 38  means that, yes, it has reached the Absorb set point, but is at zero watts or REAL close to zero.  Usually it means that there is a second charging source  BUT  you may have found an anomaly with LFP batteries ?   That it stays up at the Absorb voltage without dropping by itself and so requires close to zero watts to stay there ?   RFR 38 also requires that the voltage is there for 90 seconds.

Does that make sense ?

Not sure exactly what made it shut again this morning after it started charging.
But now it is RFR 38   66v in PV and battery 53  so it won't start charging again.
I guess it skipped going to float right away.
Looks like I am going to have to raise the PV voltage for this to work properly.
At least I can try that .
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

boB


Larry, is your PV input voltage typically like 1.0 or say 1.5 volts shy of making the Classic turn on ?

IF so, (I shouldn't say this really but in your case, the input voltage is so low it should not hurt anything), you might try going into TWEAKS and adjust the PV input offset to read 1 or 1.5 volts HIGH.

At much higher input voltages compared to the battery voltage, you wouldn't want to do that but in your situation, it should not hurt anything to at least try this.

boB
K7IQ 🌛  He/She/Me

ClassicCrazy

Quote from: boB on July 14, 2022, 01:42:42 PM

Larry, is your PV input voltage typically like 1.0 or say 1.5 volts shy of making the Classic turn on ?

IF so, (I shouldn't say this really but in your case, the input voltage is so low it should not hurt anything), you might try going into TWEAKS and adjust the PV input offset to read 1 or 1.5 volts HIGH.

At much higher input voltages compared to the battery voltage, you wouldn't want to do that but in your situation, it should not hurt anything to at least try this.

boB
I didn't think to try that in Tweaks .
I just plugged 3 in series though and it went into float .
Glad the hornets nests on my PV weren't too close to my connections !
I will run it this way for a bit and see how it goes.
I just need to see if I have a matching panel  around so I can put it in series with the two extra PV that are now disconnected. I have room on the rack for it.
Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

ClassicCrazy

Quote from: boB on July 14, 2022, 01:42:42 PM

Larry, is your PV input voltage typically like 1.0 or say 1.5 volts shy of making the Classic turn on ?

IF so, (I shouldn't say this really but in your case, the input voltage is so low it should not hurt anything), you might try going into TWEAKS and adjust the PV input offset to read 1 or 1.5 volts HIGH.

At much higher input voltages compared to the battery voltage, you wouldn't want to do that but in your situation, it should not hurt anything to at least try this.

boB

Bob ,

I put my PV back in 2 series reconfiguration and Tweaked up the PV voltage  to make it turn on. Seems to be working fine now. I think I had to go 3v higher in tweak offset but I don't see why that should hurt anything because once it turns on the charge , the charge voltage drops to the proper range. I will have to keep an eye on it since I just made that change . But the Classic certainly is running a lot cooler now and the fan doesn't need to run any or much .

Larry 
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

boB

Quote from: ClassicCrazy on August 16, 2022, 11:42:02 PM
Quote from: boB on July 14, 2022, 01:42:42 PM

Larry, is your PV input voltage typically like 1.0 or say 1.5 volts shy of making the Classic turn on ?

IF so, (I shouldn't say this really but in your case, the input voltage is so low it should not hurt anything), you might try going into TWEAKS and adjust the PV input offset to read 1 or 1.5 volts HIGH.

At much higher input voltages compared to the battery voltage, you wouldn't want to do that but in your situation, it should not hurt anything to at least try this.

boB

Bob ,

I put my PV back in 2 series reconfiguration and Tweaked up the PV voltage  to make it turn on. Seems to be working fine now. I think I had to go 3v higher in tweak offset but I don't see why that should hurt anything because once it turns on the charge , the charge voltage drops to the proper range. I will have to keep an eye on it since I just made that change . But the Classic certainly is running a lot cooler now and the fan doesn't need to run any or much .

Larry

Excellent !
K7IQ 🌛  He/She/Me

ClassicCrazy

#9
Bob,
Is the same formula used to go from Absorb to Float ?
The lithium holds the voltage up for awhile before it goes to float, and then has to use some of the power from battery for loads.
See photo of voltages from yesterday.
Can you think of a way to get to go to float sooner ?
I have the absorb set for 55.4 and the float set for 54.5 v
The photo shows that it had finished absorb and the target voltage was 54.5 float but the battery voltage was down to 53.1v and still had 38 reason for resting .
Larry
system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable

boB


Larry, when a battery has just finished Absorb, the voltage will have to fall to just below Float voltage for the Classic to turn on.

How much load was on the battery when it finished Absorb ?   Lithium might just be too stiff of voltage for a controller to help out at that time.

Maybe we are going to need a new type of algorithm for such things ?   I don't really know.

boB
K7IQ 🌛  He/She/Me

Wizbandit

Set REBULK to just under FLOAT. And ABSORB time low, like 5min...
Try REBULK=53V