MidNite Guru Needed!, Kid Charging LifePO4 issue's

Started by chris, August 03, 2022, 10:19:08 AM

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ClassicCrazy

Quote from: chris on August 31, 2022, 09:21:13 AM
Quote from: FNG on August 25, 2022, 06:55:20 AM
So check something for me, Well after sundown when the kid should be resting please look and see if it still says float not resting. A phenomena on the kid I have seen is if the float voltage is lower than its resting voltage or another source holds the battery voltage up the kid will not go to resting thus it never sees a new day.

if this is the case take note of the battery voltage at this time (I would say like 8pm just for a good consistent time) and try setting float just above that.

Also can you share the Absorb and float settings and brand of battery.

I will talk to the Customer Service tech as well as they should have had you check this first to save the hassle of swapping the kid

Ryan

  Hi Ryan,
   I had checked the voltage a few times at night, the batteries usually sat around 13.2 iish with the display reading "resting"
Settings are 13.4 float 14.2 absorb for 20 min and 5 amp end amps (set to the whiz bang Jr)  my Battery, 4x280 amp/hr cells with a 200 amp JBD BMS with blue tooth.

   Not only would the Kids not start a new day.....but many days they just switched to float without ever hitting the absorb voltage.

  I had spoken to you a few times via email, And did try moving all of the setting up and down several points as per your suggestion... But it didn't help

Sadly,  I was so frustrated after weeks on the road having to re-boot the unit every morning and sometimes again mid day that I stopped and bought a Victron 100/50.  I hooked this charge controller up with all the same wiring and settings and have never had an issue since.

  It's really to bad as I do prefer the MidNite product.  (and well now I have a spare charge controller sitting in the garage)

Chris - I only skimmed over your posts on this topic. I was having an issue with my Classic going into resting after Absorb and just sitting there for a long time. I finally figured out that my PV voltage was too low for some reason - even though well above the Float setpoint. I used Tweaks to adjust the PV voltage that the Classic saw up about 4 volts ( on a 48v battery system) and that was what was wrong - it needed that for some reason and now all the transitions from wakeup, to absorb, to float work okay.
I don't remember all the settings on the Kid - or if it has the Tweaks for compensating the PV voltage  , but if you ever dig out your Kid again you might want to try turning it up . I forget what your setup was like type of PV and battery , etc - but something to consider trying to see if it makes any difference. I know the Kid is different than the Classic but that is what worked for me if your PV voltage isn't a lot higher than your charging voltage .
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

chris

Quote from: ClassicCrazy on September 21, 2022, 01:26:06 PM
Quote from: chris on August 31, 2022, 09:21:13 AM
Quote from: FNG on August 25, 2022, 06:55:20 AM
So check something for me, Well after sundown when the kid should be resting please look and see if it still says float not resting. A phenomena on the kid I have seen is if the float voltage is lower than its resting voltage or another source holds the battery voltage up the kid will not go to resting thus it never sees a new day.

if this is the case take note of the battery voltage at this time (I would say like 8pm just for a good consistent time) and try setting float just above that.

Also can you share the Absorb and float settings and brand of battery.

I will talk to the Customer Service tech as well as they should have had you check this first to save the hassle of swapping the kid

Ryan

  Hi Ryan,
   I had checked the voltage a few times at night, the batteries usually sat around 13.2 iish with the display reading "resting"
Settings are 13.4 float 14.2 absorb for 20 min and 5 amp end amps (set to the whiz bang Jr)  my Battery, 4x280 amp/hr cells with a 200 amp JBD BMS with blue tooth.

   Not only would the Kids not start a new day.....but many days they just switched to float without ever hitting the absorb voltage.

  I had spoken to you a few times via email, And did try moving all of the setting up and down several points as per your suggestion... But it didn't help

Sadly,  I was so frustrated after weeks on the road having to re-boot the unit every morning and sometimes again mid day that I stopped and bought a Victron 100/50.  I hooked this charge controller up with all the same wiring and settings and have never had an issue since.

  It's really to bad as I do prefer the MidNite product.  (and well now I have a spare charge controller sitting in the garage)

Chris - I only skimmed over your posts on this topic. I was having an issue with my Classic going into resting after Absorb and just sitting there for a long time. I finally figured out that my PV voltage was too low for some reason - even though well above the Float setpoint. I used Tweaks to adjust the PV voltage that the Classic saw up about 4 volts ( on a 48v battery system) and that was what was wrong - it needed that for some reason and now all the transitions from wakeup, to absorb, to float work okay.
I don't remember all the settings on the Kid - or if it has the Tweaks for compensating the PV voltage  , but if you ever dig out your Kid again you might want to try turning it up . I forget what your setup was like type of PV and battery , etc - but something to consider trying to see if it makes any difference. I know the Kid is different than the Classic but that is what worked for me if your PV voltage isn't a lot higher than your charging voltage .
Larry

Hi Larry,
  I appreciate your suggestion.  At some point here I'm going to put together a ground deploy array for shady campsites. If I can get the kid to function properly I would love to make use of it.
 
    So my current array that I took the kid off (i experiment with 2 & 4 panels)  all in parallel.

195watt
Vmp 38.3
Imp 5.09
Voc 45
Isc 5.45

   I could try putting 2 of my panels in series and see if that makes a difference
 
System 1
12 volt system,
280 AH DIY LifePO4 with 200amp JBD BMS
4x200 Watt 36volt panels 4P
MidNite Kid, WBjr
2000 watt Kisae SW inverter

System 2
Off Grid RV (parked and used as a cabin)
12 volt system,
4 X T-105+
6X100 watt array wired as 3 strings
MidNite Kid, WBjr & MNBTS
1500 watt Cotek SW

ClassicCrazy

Chris -
Well I doubt my suggestion would help since it looks like your PV voltage is well above the 12v battery charging voltages.
But maybe it will work for some other reason .
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

I connected my Kid to a 12v lithium battery today . The Kid had it's input from 24v battery system.
The Kid initially started charging but went to absorb too fast. I had too much wire on the way to the battery ( temp setup) and then calibrated offset for the wire.
It still doesn't like to charge , goes to resting and won't go back to bulk even though well below the setpoint.
I have used the Kid like this in past to charge 12v lead acid batteries and no problems.
Something about  the lithium it just doesn't seem to want to charge properly.
I gave up - charging this new battery for a friend so will try a different approach tomorrow not using the Kid.

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

littleharbor2

#19
Longshot here but worth checking.
Check the clock in the controller. I was having the same Float in the am issue and one of the experts here pointed me toward the clock being off. He was right, problem solved. My controller is a Classic 200 but your controller may have a similar clock set up.

Here's the original thread.
http://midniteftp.com/forum/index.php?topic=5809.msg53077#msg53077
12 Suntech 175's
   Classic 200
   Bogart Tri Metric
   Trace SW 4024 (brand new, sort of, first energized Feb. 2015)
  460 Ah. 24 volt LiFePo4  Battery bank

boB


  Larry, what kind of BMS is in this 12V system ?

  Since the source, a 24v battery, has a very low impedance, it could be that the current spiked up and the BMS disconnected ?

  I hear about a LOT of problems with BMS's for lithium batteries turning off.  Some can't even turn on an inverter connected to a Li battery
    without the BMS turning itself off.

  boB
K7IQ 🌛  He/She/Me

ClassicCrazy

Quote from: boB on December 04, 2022, 07:12:49 PM

  Larry, what kind of BMS is in this 12V system ?

  Since the source, a 24v battery, has a very low impedance, it could be that the current spiked up and the BMS disconnected ?

  I hear about a LOT of problems with BMS's for lithium batteries turning off.  Some can't even turn on an inverter connected to a Li battery
    without the BMS turning itself off.

  boB

It is an SOK 12v battery - not sure what kind of bms is in it. But it has a nice bluetooth app so I was watching the data from battery directly which shows voltage ,current, etc and it didn't look like it ever shut off or send any alarms.
I think the problem some of those batteries have with inverters is when they first hook up there is a huge inrush to charge the capacitors . Some of the newer 48v lithium batteries have precharge circuits in them to avoid that. But I also read about people using a pencil to precharge the capacitors in inverters first .
I didn't spend too much time messing around with the Kid since it was cold out in the shed where I had it.
I just got a Riden 60v 24 amp power supply that I am going to use to charge that 12v battery . I was working on hooking that up today - I got it without AC power supply and am going to power it with my 48v lithium battery system.
That has a special battery charging jack and features like CC and CV  that you can set however you want. But of course there is the learning curve so I got the power supply  hooked up to power but now have to figure out all the menus and option on how to use 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

FNG

We recently found a bug in the kid that causes this. Mario should have new code this week to test that fixes this issue.

ClassicCrazy

Quote from: FNG on December 05, 2022, 11:55:54 AM
We recently found a bug in the kid that causes this. Mario should have new code this week to test that fixes this issue.

Good to hear - if the code comes out while I still have the battery here I can give it a try.

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

dapdan

Mario/Midnite,

Are we there yet. My controller is also not coming out of float, while providing no power, without a reset of the PV breaker. Is that new code out it has been about 2weeks since someone said it was coming out a week ago. Any progress. we literally have two testers to see if the new code works. One using Lifepo and me, using NMC lithium ion batteries.

Damani

Timmy

Any update on this? I have switched to lithium and am having a terrible time with my controller due to this problem. My system is on a boat and when I head out there to have fun and find the controller never woke up and my entire system died it's a massive disappointment. To add insult to injury I'm running a 24v lithium battery and I have to "jump start" which is a real process due to the remoteness of the location.

I have looked at the FAQ. I have tried several strategies regarding setting the float voltage. Setting the float to the resting voltage of 27.2 seemed to work for some time but I just came back to a dead system today. What am I missing? I have these settings from the manufacturer and have entered all relevant settings into the kid.

Charge/bulk/boost voltage 28.8V
Absorption voltage 28.8V
 Over voltage disconnect 30V
Over voltage reconnect 28.4V
 Tail current 2A(0.02C)

Under voltage warning 23.2V
Under voltage recover 24V
 Low voltage disconnect 21.6V
Low voltage reconnect 24.8V

boB

Quote from: Timmy on September 02, 2023, 07:28:41 PMAny update on this? I have switched to lithium and am having a terrible time with my controller due to this problem. My system is on a boat and when I head out there to have fun and find the controller never woke up and my entire system died it's a massive disappointment. To add insult to injury I'm running a 24v lithium battery and I have to "jump start" which is a real process due to the remoteness of the location.

I have looked at the FAQ. I have tried several strategies regarding setting the float voltage. Setting the float to the resting voltage of 27.2 seemed to work for some time but I just came back to a dead system today. What am I missing? I have these settings from the manufacturer and have entered all relevant settings into the kid.

Charge/bulk/boost voltage 28.8V
Absorption voltage 28.8V
 Over voltage disconnect 30V
Over voltage reconnect 28.4V
 Tail current 2A(0.02C)

Under voltage warning 23.2V
Under voltage recover 24V
 Low voltage disconnect 21.6V
Low voltage reconnect 24.8V

I will find the answer to this on Tuesday or Wednesday.

Should be an easy answer.

Having said that, has anyone checked to see if there is a "Skip Days" in the Kid that would cause this ?

boB
K7IQ 🌛  He/She/Me

Wizbandit

With lithium you need to set REBULK to .5v or 1v less than FLOAT.
FLOAT MPPT is tailored for lead and won't pull power from the PV in FLOAT until the lithium battery is about 50% SOC or less on a 24V system, usually late afternoon and not enough sun to get it charged up before night.