KID sync mode - how does it function?

[pobox88]

I have two KIDs on identical solar PV array setups. (Installed it up this way to give/allow redundancy if one system goes belly up).
The PV arrays are located next to each other same orientation and no shadin.

Questions:

Is it normal for one KID to be resting while the other is running in BULKMMPT?
Why does one KID have its full charge and float LEDs on, while the other does not?

The KID with the WHIZZBang is the unit resting and no LEDs illuminated. It has also started clicking
after running in sync mode for a week, both array strings are in full sun.

[Westbranch]

Suspect there is a WBjr setting that is causing the difference.
Please post the settings for each so we can understand justwhat might be going on.

[pobox88]

Just updated to version 1856 firmware. My best guess, it was the loss of communication between the two KIDS. I can't remember where I read about the sync/communication problem, but in my case it appeared after three to five days after resetting the KIDS and re-entering the battery specs. So far 1856 is working well ... thanks guys

It's nice to see the "M" and "S" displayed on the LCD. Gives confidence that the sync setup is running as expected.

Is there a way to set the date to local time?

cheers all

[pobox88]

The issue is back. The KIDs are "resting" again at random times.

It's as if there is a loss of comm's between the two KIDs, and then they randomly re-establish comm's and then both KIDs start charging together.

@ Westbranch - I don't think it's a Whizzbang setting, the issue still exists when the Whizzbang is deselected.

[WizBandit]

I had Mario add "sync data LEDs" so I could tell if the sync was broken.
If the KIDs become un-synced the RED ERROR LED will light.
The MASTER will send a data packet and blink the 2WK LED, when the SLAVE receives this data it will blink the 2WK LED about 8 times.
If you get a RED LED you can tell if the problem is the MASTER not sending or the SLAVE not receiving.

Wbjr must be in the MASTER as well as the BTS.  The new default for ENDAMPS is now 0.0 and not 0.1 as it used to be.  This was causing issues in ABSORB Mode and SYNC Mode.  It is not uncommon in ABSORB for one KID to go RESTING as it has nothing to contribute to the charging current.

[ClassicCrazy]

I had Mario add "sync data LEDs" so I could tell if the sync was broken.
If the KIDs become un-synced the RED ERROR LED will light.
The MASTER will send a data packet and blink the 2WK LED, when the SLAVE receives this data it will blink the 2WK LED about 8 times.
If you get a RED LED you can tell if the problem is the MASTER not sending or the SLAVE not receiving.

Wbjr must be in the MASTER as well as the BTS.  The new default for ENDAMPS is now 0.0 and not 0.1 as it used to be.  This was causing issues in ABSORB Mode and SYNC Mode.  It is not uncommon in ABSORB for one KID to go RESTING as it has nothing to contribute to the charging current.

I had wondered why the end amps was in 0.1 and thought there must have been some functional reason. Funny how little things like that can mess things up ! I don't have synced Kid's but having those LEDs to prove the link is a great idea and should really help .

Larry

[pobox88]

Help please, I'd really like to get my KiDs working together as a team.

At 70% SOC, full sun, only the slave KiD is charging. The master KiD is resting. Ambient temp is 20C.

I essentially have two systems (like the attachment), the Master KiD having the Whizbang and temperature sensor installed.
The PV panels have the same location, placement, and solar radiation exposure (except for the odd cloud).

My battery bank is made of 48 x 6V US Batteries, giving me 48V and 464Ahr.

Anyone have some ideas as to what I've not set properly?

[ClassicCrazy]

Help please, I'd really like to get my KiDs working together as a team.

At 70% SOC, full sun, only the slave KiD is charging. The master KiD is resting. Ambient temp is 20C.

I essentially have two systems (like the attachment), the Master KiD having the Whizbang and temperature sensor installed.
The PV panels have the same location, placement, and solar radiation exposure (except for the odd cloud).

My battery bank is made of 48 x 6V US Batteries, giving me 48V and 464Ahr.

Anyone have some ideas as to what I've not set properly?

From what Whizbandit said above
" Wbjr must be in the MASTER as well as the BTS.  The new default for ENDAMPS is now 0.0 and not 0.1 as it used to be.  This was causing issues in ABSORB Mode and SYNC Mode. It is not uncommon in ABSORB for one KID to go RESTING as it has nothing to contribute to the charging current."

So my question would be  - Is your Kid in Absorb when you see your Master Kid resting ?
From what Whizbandit said that is normal because only one Kid is needed at that point to supply the current needed to do Absorb.
Also as he said make sure the End Amps is set to 0 on both Kids.

Larry

[pobox88]

WBjr and BTS are both connected to MASTER-KiD.

I have set both KiD end-amps to 0.

I see "BulkMMPT" on the slave-KiD when the MASTER-KiD is resting. Should I be seeing "Absorb" instead of BulkMMPT on the slave-KiD LCD display?
This "resting" state seems to begin when SOC reaches approx. 90%.

What parameters for AUX for the slave-Kid should I be setting?

I understood that BulkMMPT meant the KiD was going all-out supplying maximum charge to the batteries. I derived this
information from watching a Midnite Solar tute on YouTube. Is my understanding awry?

I may be confused with my battery terminology vs KiD terminology.

My supplied US2200 XC2 battery specs:
Each battery is 6V 3 cell - my bank is ser/par, 16 batteries in total giving me 48V and 464A @ C/20.

Bulk Charge @ ~10% of C/20 Ah, 2.45Vpc
Absorption Charge @ 3% of C/20 Ah, 2.45Vpc for 2-4 hrs or dV/dt (4mV/cell per hour)
Float Charge @ 2.17 Vpc
Equalisation Charge 2.55Vpc 1-3 hours

[ClassicCrazy]

I think what you need to do is check and see if your battery voltage is at Absorb voltage when one of them goes resting. If so I would think it is in Absorb.
The 90% SOC reading you are reading doesn't really tell if it is in Absorb or not. SOC is more of an estimate and depends on how you set it up and you may need it to be more accurate. But most systems would be in Absorb at 90% because by then under charge the battery voltage would have gotten to the Absorb setpoint.

I don't have the setup that you have so not sure if the Slave Kid should be showing the correct state of charge if the Master Kid is resting.

If you are not using ending amps to to terminate the Absorb you must have Absorb time set so that at the end of Absorb time it will go to Float.

You may want to open  an information request ticket with Midnite and ask them.


Larry

[pobox88]

Thanks CC, your info has been very helpful.

Today I observed the KiD flickering between BulkMMPT and Absorb as the PV panel voltage varied due to a smoke haze that has been hanging around. As the voltage rose above my pre-set 58.8V Absorb the KiD displayed "Absorb" then "BulkMMPT" when the voltage fell below 58.8V, and up and down it went during the Absorb charge phase.

Also, I now have a clearer understanding of what the WBjr %SOC actually means.

Question: When can I run battery Equalization, do I need to set both KiDs to Equalize? Or is Equalization controlled solely by the Master KiD?
Lastly, can I run Equalization if the KiDs have not reached Float? (i.e. can I force Equalization at any time irrespective of the SOC?) The reason I ask is that due to clouds and smoke during the last five weeks and recent battery maintenance (and I haven't run Equalization for a couple of months) I am keen to run Equalization asap. Clouds and smoke will be hanging around for a few more weeks.

Hope you're OK with me picking your brains. Thanks again.

[ClassicCrazy]

On my Kid I can force Equalization  by going to it on the menu .

The SOC you usually have to tweak with the efficiency setting to get it to be more realistic for your batteries.

Larry