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Need Help with Charge controller settings.

MixingMasters

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Feb 14, 2021
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I have a Midnight The Kid Charge controller hooked up to 4 6v Interstate batteries as a 12v system. I am using a shunt with the wiz bang jr. I also have a temp senor on the batteries. I have the Battery info added to the Charge controller. Batteries are stored in a room temperature environment 100% of the time.
I do not use the battery bank for anything currently other than on demand backup.
In my mind if it gets a full charge during the day and doesn't use any of it's power, the next day should only need maybe a trickle charge. Instead it goes through a complete charging cycle.
Example; Complete charge day one. Sun comes up day two and bulk charge has started charging at 15-20 amps for like 3hrs. You can hear bubbles and it vents the hydrogen. During the charge controller cycle it seems to spend very little time in absorb and float, and most of the time in Bulk.
After a few weeks of this I will need to add water. After a day of charging if i disconnect the panels and let things settle like over night I can measure the battery bank and it will read 12.7 -12.8 with a multi-meter. This voltage will remain the same for days. So I cant figure out why my charge controller seems to think it needs to do a charge cycle again if the batteries are full.
Thank you so much for any help or advice you can give.
 
Example; Complete charge day one.
So what exactly is a complete charge? To what voltage are you charging? What does the manufacturer say to charge it to?
You can hear bubbles and it vents the hydrogen.
After a few weeks of this
Weeks? Egads, not good.
settle like over night I can measure the battery bank and it will read 12.7 -12.8 with a multi-meter.
Yes, thats the nominal voltage where they tend to settle when 100% charged.

Banging the voltage off the ceiling everyday is unnecessary, especially with whatever charge controller settings you have. Speaking of which, what is the charge profile your charger uses?
4 6v Interstate batteries
What type of battery is this? Is the SCC set for that type?
 
So what exactly is a complete charge? To what voltage are you charging? What does the manufacturer say to charge it to?


Weeks? Egads, not good.

Yes, thats the nominal voltage where they tend to settle when 100% charged.

Banging the voltage off the ceiling everyday is unnecessary, especially with whatever charge controller settings you have. Speaking of which, what is the charge profile your charger uses?

What type of battery is this? Is the SCC set for that type?
Complete charge.... in this case i meant a charge cycle. as in the day starts, sun comes up, bulk charging begins. After "X" amount of time the charge controller goes into rest mode and a light comes on telling me that the battery bank if fully charged.

I believe the MFG specs say to bring it to 15.3v. I don't remember off the top of my head but I know it is set to the MFG (of the battery) specs.

Weeks is a educated guess. I just topped off all 4 batteries tonight and it took almost a whole gallon. The fluid level was right at the top of the plates. I filled to 1/8 short of the bottom of the vent port per MFG instructions.

This is the MFG Specifications: Bulk-14.4, Absorption-15.3, Float-13.4. EQ-15.6.
I am using a custom profile with these numbers with the exception that there is no setting to enter the Bulk voltage. Only the absorb and float. I have never used the EQ yet due to i have not felt confident in the system yet.

The Charge controller is set for Flooded lead acid batteries. It is also being told there are 2 battery's since it is mimicing 2 230 amp hr 12v batery's totaling 460AH going based on the sticker.. The battery's used are Interstate GC2-XHD-UTL. If you are googling these they are the black battery with the Green top. 3 cell. Wired parallel and series for a 12v system.

Hop that brings stuff up to speed. Thanks for the responses.
 
Your controller WILL begin it's charging program everyday as soon as their is sufficient sunlight.

It will see that the batteries are 12.7-12.8 and want to bulk them up.

I would stick to the charging specifications of your battery manufacturer.
 
I am not familiar with the controller you are using, however the information from Midnight suggest that with the optional shunt and associated circuit you can program an 'end amps' to terminate the charge process and drop to float. Have you tries this? ( try 2% of C20 rate of the pack)
The Interstate charge voltage for absorption seems high compared to other similar flooded batteries, ( Trojan ,14.8 volts, Rolls 14.7). Some manufactures have higher charge voltages for batteries that are cycled rather than used as standby.
I suggest you lower the voltage setting for absorption to a value lower than the Interstate value, perhaps to 14.4 to 14.7 volts and equalize the batteries every few/several months.

Using specific gravity readings (SG) and relating to the manufactures data will help the 'housekeeping' of the batteries.

I dont know of any solar chargers that allow programming of different voltages for the bulk stage 'target' volts and absorption volts.
In my view, a better strategy for standby battery banks would be, that after a certain time in float condition, the charger drops to a 'stand by state', with a very low float or no float at all. There would be a 'wake up' charge every several days or when a load occurred on the battery pack.

Mike
 
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If i stick with the settings i have now (MFG) then i am pretty sure i am going to ruin something.

I have the shunt setup that you are referring to and watched a video on setting it up. What is supposed to happen is when it reaches the target "end amps" it dosnt seem to shut off or change how it is charging. It just stays in bulk. It seems to be sticking to the Timed cycle. When I set the "end amps" it didn't seem to change anything. I tried this about a week ago. I also read about playing with the battery efficincy setting in the controller but the controller just does what it wants. I am ready to juck this thing and find something more straight forward.

It seems like when it comes to the actuall charging process my plug in the wall charger does a better job.
 
Maybe someone can tell me this. I am trying to get my battery efficiency setting to where it needs to be. If my charge controller says my SOC is 100% and it is still charging the bank. Do i need to increase or decrease my efficiency setting to get that matched up?
 
I'm unfamiliar with the "efficiency" setting.

when it's still charging is there a load? Float will allow the power to flow directly from the panels. The charging you see will be the draw of the load.
 
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The efficiency setting on here if a % number of how efficient your battery bank is. Supposedly if i set it to 90% and the SOC is 100% but it is still charging then I need to increase or decrease the % number to make the SOC hit 100% when the charging is complete. Not sure which way to adjust.

There is no load. I have been just trying to use the solar pannels to keep the battery's topped off each day to maintain them for use in an emergency or when I want to use the power. Once I feel it is working correctly then I will try to see how many Watt hrs I actually have available to use and allow the solar panels to recover the bank.

Is there a more simple Charge controller that will do what I want that will handle the panels input. This seems so over complicated for something so simple.
 
More info needed. Haw many panel?, how are they connected? What are the panel specs?
Just a guess here, but you might "try" lowering bulk charge setting to 12.8 where battery likes to rest. Then "maybe" it would go straight to float?
You said,This is the MFG Specifications: Bulk-14.4, Absorption-15.3, Float-13.4. EQ-15.6 "Try Bulk 12.8 Absorption 13.6 Float 13.2" can't hurt anything. You can always go back if it doesn't help.
 
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This is a good point. What I find difficult is determining when the bank is actually at a Full charge. Since once you stop charging at any point on these types of batteries, you have to wait a while for things to settle to see what state of charge it really is. I thought that was the point of the shunt and the Wizb jr add-on. The charge controller is supposed to be able to look at the voltage and amps to see that it is fully charged. If a plug in the wall battery charger can be hooked up and charge till it sees the battery is full. Why is this so complicated for a charge controller especially since i am providing it with tons of information to help calculate the process. ie.. the MFG specs and so on.

Question. IF the battery bank fully charged and then the battery bank is completely disconnected from everything except the battery's themselves, Approximately how long should it be able to hold that charge in days. So lets say day 1 full charge after resting voltage sits at 12.7, 12.8. How many days should it be able to hold that 12.7. What would be acceptable amount of time just sitting there in days to drop down to 12v flat.

As to your question I am running two 315 watt panels. they are wired in series I think. I forget which one is which. It is the one that gives me the higher voltage so that in cloudy days I still get good wattage. On best sunny days I can get about 280-315 watts. Mostly due to how I have the panels mounted.

My problem and concern is that like I said it is supposed to see the state of charge and know when it is full. But it acts like instead it is charging based on a time table not End amps. If it is a cloudy day it will charge all day and i get that. I consider that normal, it hasen't reached the end amps yet. But the really sunny days, by noon controller is showing 100% but will continue charging for hrs. If I know it is completely fully charged and i was to disconnect the bank from the controller via switch, then turn it back on the charging process will start all over again instead of seeing that is already charged. Now I fear that the battery's have been damaged in some way and are not functioning properly hence the Question in second paragraph.

I found a cool toy to do your own testing by putting a draw on the battery's for 20hrs to check their performance but it coasts 300 bucks.

Special thanks to any that are still giving this any attention.
 
NOTE: Due to the potential risk of further damage that may be being caused my set up is currently unplugged and I have a trickle charger on the bank.
 
Question. IF the battery bank fully charged and then the battery bank is completely disconnected from everything except the battery's themselves, Approximately how long should it be able to hold that charge in days. So lets say day 1 full charge after resting voltage sits at 12.7, 12.8. How many days should it be able to hold that 12.7. What would be acceptable amount of time just sitting there in days to drop down to 12v flat.
A week or so. There is ? % of loss expected. But not sure what that # is, may be 3% a wk?
As to your question I am running two 315 watt panels. they are wired in series I think. I forget which one is which. It is the one that gives me the higher voltage so that in cloudy days I still get good wattage. On best sunny days I can get about 280-315 watts. Mostly due to how I have the panels mounted.
If controller is PWM, panels must be parallel. Mppt doesn't mater how you connect.
My problem and concern is that like I said it is supposed to see the state of charge and know when it is full. But it acts like instead it is charging based on a time table not End amps. If it is a cloudy day it will charge all day and i get that. I consider that normal, it hasen't reached the end amps yet. But the really sunny days, by noon controller is showing 100% but will continue charging for hrs. If I know it is completely fully charged and i was to disconnect the bank from the controller via switch, then turn it back on the charging process will start all over again instead of seeing that is already charged. Now I fear that the battery's have been damaged in some way and are not functioning properly hence the Question in second paragraph.
When disconnecting, Panels 1st, Battery last. Connecting is opposite.
I found a cool toy to do your own testing by putting a draw on the battery's for 20hrs to check their performance but it coasts 300 bucks.
 
Hey thanks for that Link. That looks awesome. Very excited to try that out.

It is a Mppt controller. so your right watts are watts so it wouldn't matter.

and yes that is how I disconnect and reconnect them.

So after testing the bank and making sure they are still working and efficient. I am still stuck with my controller seeming like it has a mind of it's own. Meaning it is not doing what I am Expecting it to do. Now I need to try to figure out what it is doing and how to adjust it so that it is not cooking my batteries. It really boils down to i hate this controller. Even in so called professional videos of how to set this up they don't seem to know the proper settings.

Does anyone have any good recommendations for a charge controller that would be a bit more user friendly. I am trying to avoid the crappy Chinese stuff I see online but I am just not familiar with the brands or interfaces. All i seem to find are ones that are just barley to small for my panels or jump up to 500 bucks.

Thanks agian for all the help.
 
Does anyone have any good recommendations for a charge controller that would be a bit more user friendly. I am trying to avoid the crappy Chinese stuff I see online but I am just not familiar with the brands or interfaces. All i seem to find are ones that are just barley to small for my panels or jump up to 500 bucks.

Thanks agian for all the help.
Will P has many controller videos. I use a Epever with a MT-50, they have many different sizes. When buying go as big as you can afford, amp wise. If you go small your most likely just going to upgrade in the future.
Did you try settings I gave you in post #11. They might work?
 
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I have not yet. I have somthing coming up monday and going to wait till after since I have things disconnected. So probably wed or so i will connect everything back up and give it a go. When i have a result i will post it.
 
Side note I've been watching Will P for a while now. I was shocked when I looked up how to use that load tester found his video. I didn't even know he every used one of those. He is where I found the $300 version. To be honest I wish I could just sell the batteries and controller and get a couple battle born and a more user friendly controller. He has come along way since I started watching him. Will is how i came about this fourum as well.
 
In my opinion better deal than Battle Born. Also Will likes these too. He has video of teardown.
 
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