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EPEVER 4210AN Charging Parameters Issue

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I'm trying to set my charging parameters for my setup. I have 4 - 100 Watt panels, 2000 Watt Pure Sine Wave Inverter, 20 Amp DC-DC Charger, 2 - 100 Ah SOK batteries, and this EPEVER as my MPPT. I went into the MT50 and changed the battery type to USER and was able to change everything except three parameters. The problems I have are as follows:


1. SOK said they want the Boost Charge Voltage to be 14.6 but the MPPT manual says it has to be equal to the Equalize Charging Voltage which SOK wants to be 14.4.

2. The MPPT manual says the Low Voltage Reconnect has to be greater than the Low Voltage Disconnect and SOK wants the Low Voltage Reconnect to be 10 while the Low Voltage Disconnect should be 11.

3. The Under Voltage Reconnect Voltage stays at 11.6 and won't go to SOK's requirements of 11.5. This is because the Under Voltage Reconnect Voltage has to be greater than the Under Voltage Warning and SOK says both need to be 11.5.



Below are the charging parameters directly given from SOK (I am putting a * next to the parameter for each issue, so for example - the charging parameters for issue 1 will each have one * next to it, Issue two will have two ** and Issue 3 will have *** next to them):

Over Voltage Disconnect 14.7 V
Charging Limit Voltage 14.6 V
Over Voltage Reconnect 14.6 V
*Equalize Charging Voltage shut off or 14.4 V
*Boost Charging Voltage 14.6 V
Float Charging Voltage 13.6 V
Boost Reconnect 13.3 V
**Low Voltage Reconnect 10
***Under Voltage Warning Reconnect Voltage 11.5
***Under Voltage Warning 11.5
**Low Voltage Disconnect 11.0
Discharging Limit Voltage 10.5
Equalize Duration 0
Boost Duration 180 minutes


EPEVER Manual:


Please see page 18-19 for the charging parameters rules.
 
Ignore what SOK wants.

The only settings on the Epever you need to consider are:
Equalise charging voltage 14.4
Boost charging voltage 14.4
Float charging voltage 13.4
Boost reconnect 13.3
Equalise duration 0
Boost duration 30 minutes

All the other settings relate to the load terminals of the controller , they do not control charging.

If you are using the load terminals then setup suitable values, these do not need to comply with SOK values that are related to its bms to protect the battery .
It's not recommended to discharge below 12v

Possible load output settings, or make up you own settings.
These will only effect the the load outputs, any loads connected to the battery, the usual situation, will not be controlled.


Low volts reconnect 12.5
Under v warn reconnect 12.3
Under volts warning 12.0
Low volts disconnect 11.8
Discharge limit 11.5

Mike
 
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Ah, good stuff to know! It was getting annoying because what SOK wanted I literally could not do in the MPPT because it wouldn't let me per their charging parameters rules.

Now I just have to find why I am having such a major voltage drop and I'll be good. Gunna check everything. Maybe I messed up a crimp somewhere? The wire gauge isn't (shouldn't) be an issue. I made sure to properly size everything before spending the money to buy all the wire. I'm only getting 3.5 amps max with over 30 volts.
 
I'm only getting 3.5 amps max with over 30 volts.
What is your panel arrangement? 4S, 4P, or 2S2P? With mild overcast and flat panels that sounds like 2S2P. Or?

If the batteries are nearly full you won’t/don’t get much for amperage output. 30V sounds like 2S2P but please confirm.
 
What is your panel arrangement? 4S, 4P, or 2S2P? With mild overcast and flat panels that sounds like 2S2P. Or?

If the batteries are nearly full you won’t/don’t get much for amperage output. 30V sounds like 2S2P but please confirm.

No you are exactly correct, the system is setup in 2S2P. Is this normal? Should I go to a 4S or 4P? I was trying to find a good middle ground between sometimes being in sun and sometimes in shade. This setup is on my conversion van.
 
s this normal?
It’s normal for hazy sun and/or full batteries. 3.5A is a bit more than 10% of what you might see in full sun with discharged batteries in boost.
With 400W you will see up to 22-ish amps in ideal conditions and cooler weather.
Should I go to a 4S or 4P?
Do you have any shading issues? That might be the only reason to 4P.

I like 2S2P.

4S would be like 88VDC open circuit and that’s too close to max volts for the charge controller which I think is 100V max.
 
It’s normal for hazy sun and/or full batteries. 3.5A is a bit more than 10% of what you might see in full sun with discharged batteries in boost.
With 400W you will see up to 22-ish amps in ideal conditions and cooler weather.

Do you have any shading issues? That might be the only reason to 4P.

I like 2S2P.

4S would be like 88VDC open circuit and that’s too close to max volts for the charge controller which I think is 100V max.

Gotcha, the batteries were saying they had 12.8 volts which is considered nominal by SOK. I will have to check what amperage I get tomorrow when the sun comes out. It will be 51 degrees F where I live as well so this sounds like good conditions to test.

Do you have any shading issues? That might be the only reason to 4P.

I like 2S2P.

4S would be like 88VDC open circuit and that’s too close to max volts for the charge controller which I think is 100V max.

I put this system on a van and even purchased the SOK batteries that work in extreme cold down to -20 C (-4 F). Because it is on a van I have no idea where I will be parking one day to the next. One day may be in full sun with zero shade and the next day may have quite a few shady spots. It all depends. This is why I went with 2S2P.
 
will have to check what amperage I get tomorrow when the sun comes out.
Unless batteries are discharged some max amps won’t occurr
this system on a van
in southern latitudes it will be better, but flat panels attenuate solar harvest. So you won’t see full potential wattage output.
day may have quite a few shady spots. It all depends. This is why I went with 2S2P.
So at least one string will need to have unshadowed sun to get any decent charge.
 
12.8 volts is less than 20% capacity so the battery should accept full current from the panels. Expect around 25 amps charge current maximum, 100 to 150 amp hours per day.
If you have shade expect a significant reduction regardless of panel configuration.
With a 24 volt system and 100 watt panels you need at least two in series to get a high enough voltage. With 4 panels completely in series connection will produce an OC voltage into the danger region of the controller Input voltage.

Mike
 
Ignore what SOK wants.

The only settings on the Epever you need to consider are:
Equalise charging voltage 14.4
Boost charging voltage 14.4
Float charging voltage 13.4
Boost reconnect 13.3
Equalise duration 0
Boost duration 30 minutes

All the other settings relate to the load terminals of the controller , they do not control charging.
Hi Mike & Others - I have an Epever 50A SCC connected up to six 100w panels and for the life of me I can't find any agreement on what my Epever settings should be for connecting to my 24v Sig Solar EG4 LifePower4 (200Ah - 8s) battery. Are the numbers you give above specifically for Sangs SOC battery pack? Yes, I understand that I would be doubling these numbers for my 24v system.

The only parameters I can find for my EG4 (attached) are a bit confusing... and don't quite translate to your list above. Not only that but I'm not sure that perhaps those EG4 numbers aren't just the specs for the built-in BMS and would NOT be the correct numbers for my Epever. Can you provide that same list of Epever numbers that you think I should be using with this 24v EG4? Note - my Epever is old enough that I must use the User settings for my LiFePO4 battery (no built-in charge profile). Thanks a bunch.
 

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Here's a PDF (& JPG) of an Excel file that lists out the Epever charge controller settings I'm hoping to determine (this forum won't allow actual Excel files). I'd be most appreciative if folks could repost it, or some more useful format, with their best shot at what those two PINK columns should contain for my Tracer 5414AN "User" configuration (details above). Can you spot anything wrong with any of these parameters? Thanks.
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The data shown above for the EG4 says,
Charge 29 v
Bulk 28.5 v
Float 28.25
Absorbtion 28.25

The third data sheet,
Charge volts, 27.6 to 28.8.

The Epever can set the bulk charge limit, boost volts.The absorbtion period has the same voltage and cannot be set to a different voltage.
The charge volts at 29 volts from the above data does not agree with the bulk and absorbtion volts. Bulk ( boost) is the charge voltage.
The third data recommendation of 27.7 to 28.8 for charge volts, is in my view, more realistic.

Where short service life of lithium batteries has occurred reports suggest the following factors may have been the cause,
High charge voltage with long absorbtion period.
High continual float voltage.

It would seem that using a charge voltage in the recomendated range 27.7 to 28.8 would be ideal.

Thus ,
Boost volts 28.0 to 28.4
Boost duration 10 minutes to 30 minutes

Float volts, set at battery resting voltage for a standby application and slightly higher where solar powers loads,
26.8 standby, 27.2 loading.

Boost reconnect , set to 0.2 volts lower than float.

Mike
 
Hi Mike - Thanks for the above but I'm at a loss for some of it.

As you can see on my updated chart I've changed two of your recommended settings (in Red). For lack of some other influencing factors I'm going to split the difference on the Boost volts (28.0 to 28.4) and use 28.2v.

You wrote:
"Float volts, set at battery resting voltage for a standby application and slightly higher where solar powers loads,
26.8 standby, 27.2 loading."

Would it be safe to cut out the middle stuff between the commas to make it read like this:
"Float volts - 26.8 standby, 27.2 loading." ?

If so, which of these two conditions would the Epever CC parameters settings page be looking for? Where did those two numbers come from? I'm only allowed a single "Float Charging Voltage" (FCV) entry?

Finally...
Apparently, I need to know "Float volts" before I can set the "Boost Reconnect" item. The problem is that I'm afraid I don't have any idea how I would determine "resting" vs "standby" voltage.
Suggestions?

Have I missed anything else in that first "pink" column? If I understand you correctly you are saying that everything in that pink column looks good except for the two red items and the, yet to be determined, "Float" and "Boost Reconnect" settings... yes?

Thanks again for you help on this.
"Ignorance is NOT bliss" ...especially where it comes to LiFePO4 !!

1651183409351.png
 
The values you are concerned about determine how the battery is charged, boost, float,. boost duration, boost reconnect. All the others determine how the Epever load output protection functions.
Although a voltage over 27.6 will charge your battery, depending on BMS settings, cell balancing capability, cell unbalance, the battery may need a voltage in excess of the BMS preset voltage above which balancing takes place, typically this is 3.4 volts per cell, 27.2 for a 8 cell battery.
So one factor that needs to be taken into account is balance time required by the battery.
A further factor is the battery SCC when the battery under charge reaches the boost 'target ' voltage.
This will depend on the charge current compared to battery capacity and boost voltage.
Add in the variable of cell quality and performance results in no single charge voltage is suitable for all batteries and charge situations.

Table 3.7 in the EG4 manual recommends,
Charge voltage 24v, charge current 30 amps, max 100 amps

The battery allows comprenshive access to BMS settings and cell status so its possible to see the effects of charger settings.
All things considered I suggest,
Boost Volts 28
Float Volts 27
Boost duration 30 minutes
Boost reconnect volts 26.8

Once the battery is in use you may need to adjust these settings slightly..

Mike
 
Table 3.7 in the EG4 manual recommends,
Charge voltage 24v, charge current 30 amps, max 100 amps

The battery allows comprenshive access to BMS settings and cell status so its possible to see the effects of charger settings.
All things considered I suggest,
Boost Volts 28
Float Volts 27
Boost duration 30 minutes
Boost reconnect volts 26.8
Updated 05/05/22:
Thanks for all your help on this but I think I'm just going to try PMing every EG4 owner I can find on this forum and beg for a copy of their SCC settings. I might get lucky and find someone with an Epever. If not I'll look for consensus and / or trends. No need to waste any more of your time answering any more of my very frustrated, very ignorant, questions (below). You've been a big help and a great teacher. Thanks.
-------------------------------------------

Hi Mike - Thanks for hitting this again. I'm wondering where in Table 3.7 you found that "Charge voltage 24v" reference. Here's my copy of the 24v Table 3.7... I just don't see anything about 24v charging.
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Also, I'm faced with one other big stumbling block as I try to solve this problem... my BMS parameters for the EG4 battery are locked down. Sig Solar assumes that their customers are going to pair this battery with their own Growatt controller / inverter device... which DOES allow those changes to be made... but only from the Growatt. I don't have a Growatt so I don't appear to be able to make changes to the BMS settings. So... I'm just trying to get the Epever SCC to play nicely with the existing EG4 settings.

To make matters worse... Epever is famous (apparently) for using non-standard terminology for their charge parameters... so when you make a suggestion for a voltage setting I'm usually clueless if you don't use the actual Epever term for that setting. As you can see in the only info I've been able obtain from Epever itself...
1651723745971.jpeg

One last question... your suggestions (below) were made in the context of a discussion of access to the BMS but my ignorance requires me to ask... you were talking about changes to the BMS, right? ...not the Epever settings?
"All things considered I suggest,
Boost Volts 28
Float Volts 27
Boost duration 30 minutes
Boost reconnect volts 26.8
"

Thanks again!
 
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Re 24v , its a mistake, should be 28 volts.
Re BMS, I am only suggesting settings for the Epever. The reference to the BMS is that you are able to see how your charge settings are effecting the cell voltages and cell balance.

To some extent you are over thinking the situation. Unless the battery is continually over stressed, (which it wont be with solar, cause it gets dark) it will tollerate most charge conditions with the BMS protection.

Mike
 
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