Struggling with basic LiFePO4 settings in Epever Tracer

[gator]

Hello all. I am struggling to justify some basic LiFePO4 charging parameters, and relate them to how to set up my Epever Tracer 2215BN. The Epever has many charge parameters geared toward charging older chemistries. This is very confusing to apply to LiFePO4, and the fact that terminologies and recommendations for charging LiFePO4s are all over the place makes it even more difficult.

Can someone please help with some very fundamental questions?

The tracer needs settings for:

1) Charging limit voltage (is this the same as "bulk"?)

2) Equalize voltage (ok, I get that this is to be turned off with a zero duration setting)

3) Boost voltage (what is this? something else to be zeroed out like equalize?)

4) Float voltage (seems straightforward, no questions here)

Will seems to recommend an Absorption cycle and a Float cycle. Which Epever cycle is "absorption"?

Relion recommends a Constant Current cycle and an absorption cycle. Which Epever cycle is "constant current," and which is "absorption"?

Battle Born's docs seem to have use for the Boost cycle, at 14.6V with a 180 minute duration. How does this square with what Will and Relion recommend?

I have a feeling that the answers are simple, but I'm finding it very confounding. I bought the Epever at Will's recommendation, but am finding it not at all beginner-friendly for LiFePO4s. I'm on a low budget, charging two Miady 16AH batteries in parallel, they seem very promising for my application so far, and I just want to give them the best chance for long-term success.

Anyone?

Thanks, Doug

 

[MisterSandals]

charging two Miady 16AH batteries in parallel

What are the manufacturers charging recommendations? I would start there.

 

[gator]

The Miady spec sheet says "...charged to 14.6V at a constant current of 0.2C5A, and then, charged continuously with constant voltage of 14.6V until the current was not more than 0.02C5A." Suggestions for doing that with the Epever would be appreciated, but I'm really wanting to understand how to accomplish Will's recommended 2-stage charge "for all LiFePO4s" with the Epever, and how to know which features are not needed/useful for LiFePO4s. I can find virtually nothing about the BOOST cycle/settings and how/if they relate to LiFePO4.

 

[gator]

OK, in an Epever manual for a different CC, I found a description of their charging cycles, which I will summarize.

1) Bulk charging- the controller operates in constant current mode, delivering its maximum current to the batteries. (There seem to be no settings for this cycle)

2) Constant charging- initiated when the battery voltage reaches the constant voltage setpoint. This mode has 2 stages, Boost and Equalize. (There are no specific settings for a "constant voltage setpoint." Perhaps this is the "boost" voltage setting?)

Since it seems commonly accepted to disable the equalize stage with a setting of zero duration, perhaps what is left, the "boost" stage, is what Will refers to as the absorption stage?

3) Float charging. This cycle seems self-evident and I have no questions about it.

 

[MisterSandals]

There are a LOT of EPever posts that go over the settings. I would be wildly surprised if you cannot find
some expert, experience-based advice in here:

Search results for query: epever settings

diysolarforum.com

 

[mikefitz]

Settings on the Epever are confusing and some of the values relate to the charge control and some to the load outputs, the manual is not very clear on this.) Load output settings and warnings are shown in italics

note changes have been made to this post due to significant errors in the original posting. My apologies for inaccurate statements.

Alternative chargers may adopt different terminology to EPever.

Boost charge voltage = absorption voltage
Boost duration = absorption time


Over volts disconnect : if the battery volts exceed this , the load outputs disconnect from the load from the battery.

Charging limit voltage: if the battery volts exceed this, charging the battery from solar is stopped.

Over Voltage reconnect: if the load outputs have been disconnected due to the battery exceeding over voltage a reconnect will occur at this value.

Equalize charge voltage: used for lead acid batteries where a higher voltage is applied every 28 days for a duration to equalise the cells. Normally only used with flooded batteries. Use with sealed, AGM and GEL lead batteries only with manufactures approval.

Boost charge voltage: under the boost mode, the controller will charge the battery at maximum power from the solar panels until this value is reached. At all times before this 'target' voltage is reached the maximum power control process will will try to 'pull' maximum power from the panels. This is the bulk stage of charging where most of the battery capacity is restored.

Float charge voltage: once the boost duration has been completed the controller will modify the maximum power search and load the panels to produce a constant float voltage at the battery. Typically used for lead acid batteries to compensate for the self discharge. With lead acid batteries it may also 'top up' the battery. Where lithium batteries are charged setting to the resting voltage of the battery may be used.

Boost reconnect voltage: once the unit is in float mode the voltage may vary due to solar conditions and any load on the battery. If the battery voltage falls to this value the controller re enters the Boost stage.

Low voltage reconnect: if the load outputs have been disconnected due to a low battery, this voltage is the turn on value.

Under voltage warning re connect: warning turned off at this voltage.

Under voltage warning: warning set at this voltage.

Low voltage disconnect: load outputs are disconnected from the battery at this voltage.

Discharging limit voltage: other than issuing a warning at the set voltage the stand alone unit cannot do anything about this.

Equalize Duration: the time duration where the voltage is held constant with equalisation for lead acid batteries

Boost Duration: once the boost voltage has been reached the voltage will be held constant for this period. This is the absorption period where the battery is completely charged.

.
Battleborn suggest the following settings, note over time Batleborn have made changes to recommended settings.
Latest suggested settings.
Note only the bold settings relate to charging

Over Voltage Disconnect 14.7 V
Charging Limit Voltage 14.6 V
Over Voltage Reconnect 14.6 V
Equalize Charging Voltage 14.4 V ( this is not used for lithium, set a safe value)
Boost Charging Voltage 14.2 to 14.6 V, 14.4 ideal
Float Charging Voltage 13.6 V
Boost Reconnect 13.3 V
Low Voltage Reconnect 11
Under Voltage Warning Reconnect Voltage 11.5
Under Voltage Warning 11.5
Low Voltage Disconnect 10.0
Discharging Limit Voltage 10.5
Equalize Duration 0
Boost Duration 30 minutes for each 100Ah of battery

For user programming you will need the MT50 or interface cables for Android or PC.

The Boost at 14.6 and float at 13.6 may be considered by some as too high and may wish to adopt more conservative values.

Mike

 

[gator]

Mike, thank you SO MUCH for this expanded information. This is exactly the kind of information I thrive on (and geek out on). Super-helpful. Shame that it isn't included in Epever's documentation, or as a sticky note here.

If I can ask just a couple follow-up questions, I think I'll have this.

If boost/bulk is intended to deliver max power until a desired voltage is reached, why add a time constraint to it? What happens when it times out, does it go to equalize/absorb? Does a setting of zero stop the boost cycle, or simply remove the time constraint?

Same thing with equalize. Why a time constraint, and what happens when it times out?

It should be noted that Battleborn's suggested settings break the Epever rule: Low Voltage Reconnect > Low Voltage Disconnect > Discharging Limit.

Thanks!!! Doug

 

[gator]

Mike, after studying the Epever manual more carefully, with fresh eyes, I believe some of the information you'ver offered is incorrect. If anyone disagrees with my findings, please chime in.

"Boost" in Epever terminology is not equivalent to what is commonly known as "Bulk."

Bulk is the cycle the controller automatically starts the day in -- maximum MPPT charging with constant current until the Constant Charging voltage setting is achieved. There are no settings for this cycle.

Constant Charging is the second cycle, made up of two sub-cycles, Boost and Equalize, both constant voltage, and both non-MPPT.

Epever describes the Equalize cycle as intended to gasify and stir battery electrolyte. So I can see why we disable that for LFP.

Epever describes the Boost cycle as used to prevent heating and excessive gassing. I'm thinking this is the Epever default for what is commonly known as "absorption."

The third cycle in Epever's scheme is Float. As I've said, I have no confusion about this cycle.

So I am grooving best with Relion's terminology and suggestion for a Constant Current cycle followed by an Absorption cycle. Translated to Epever terminology, this, as I think I understand it now, would be Bulk followed by Boost (and yes, then Float).

I fear that if I set Boost duration to zero (along with Equalize at zero) it will go directly from Bulk to Float, so until someone suggests otherwise I will set my Boost duration to somewhere between 120 and 180.

Doug

 

[Hiesenfig]

Mike, Thank you so much!!!
This helps a lot of my understanding.

 

[mikefitz]

D

Mike, after studying the Epever manual more carefully, with fresh eyes, I believe some of the information you'ver offered is incorrect. If anyone disagrees with my findings, please chime in.

You are correct, my error, apologies for misinformation. I made numerous errors. However the recommended values from Battleborn are correct for their batteries.

The Epever charger system starts with the current at the maximum that the solar can provide.
Once the 'boost' target voltage is reached, the voltage is held constant for the 'boost period', the default time is two hours.
Can we agree, Doug, that 'Boost Duration' is equivalent to absorption period, and 'boost charging voltage' is equivalent to absorption voltage?

Once in the float stage the controller will attempt to hold the voltage at that level. If loads and solar conditions allow the voltage to fall below the 'boost reconnect,' the whole charge sequence starts over again.

The equalization voltage should be set to a the same as boost or lower ( to be on the safe side) and the equalization duration period set to zero.

Setting the boost duration, where the voltage is held constant, will depend how the battery is charged and if you need an additional time for balancing. If the charge current is low compared to the battery capacity, the boost duration could be much lower than the default 2 hours. With a high charge current compared to capacity the full period may be needed.



It seems to be accepted that, by using charge target volts lower than 14.6 volts, and also keeping the time that the batteries are at such a high level to a minimum, the battery life will be extended.
Thus a boost target of 14.2 or even lower, and a float voltage of 13.4, with a short absorption period, may be an advantage.

Mike

I have since modified the original post that contained errors.

 

[gator]

Mike wrote: "Can we agree, Doug, that 'Boost Duration' is equivalent to absorption period, and 'boost charging voltage' is equivalent to absorption voltage?"

Sure Mike, sounds like we're in agreement in that.

Unfortunately for me, your added information about boost duration is just enough over my level of incompetence that it makes my eyes glaze over. But it's ok, I think my settings are probably ok, I'm not seeking any further tutoring.

Your explanation about some of the opaque Epever settings being about the load outputs was super helpful! That was worth the price of admission right there. Thanks again.

Doug

 

[Nickco123]

Thanks guys for your comments. I’m programming my MT50 now

 

[LIFEPO4newbie]

I'm planning a LiFePO4 build when the cells I've ordered finally arrive. My plan is to replace the flooded coach battery in a Class B RV and charge it mostly with the van alternator or shore power converter through a DC/DC charger. I've already got the OverKillSolar BMS and have worked out the settings for it and the Renogy Charger. Now I'm considering adding a fold-up 100W panel and charge controller just for those cases when I am boondocking a little longer than the capacity of the new coach battery.

I've been thinking a 1206AN Epever would be the correct charge controller for a 120 watt panel, but I'm worried the user settings will disappear every time I pack it up and it is no longer connected to power. Why not just set it to Gel with the basic user interface on the screen? Based on the conversation above and the values in the manual for this battery type setting, it would seem to fall in a safe zone for the new LiFePO4 battery in a middle SOC.

From the Epever manual:

system
Battery type Voltage
Gel
Over Voltage Disconnect Voltage
16.0V
Charging Limit Voltage
15.0V
Over Voltage Reconnect Voltage
15.0V
Equalize Charging Voltage
——
Boost Charging Voltage
14.2V
Float Charging Voltage
13.8V
Boost Reconnect Charging Voltage
13.2V
Low Voltage Reconnect Voltage
12.6V
Under Voltage Warning Reconnect Voltage
12.2V
Under Voltage Warning Voltage
12.0V
Low Voltage Disconnect Voltage
11.1V
Discharging Limit Voltage
10.6V
Equalize Duration
——
Boost Duration
120 min


Thoughts?

 

[Bavrider]

Gator; where are you with you epever setup? Can you post your current settings?

 

[rickst29]

I'm planning a LiFePO4 build when the cells I've ordered finally arrive. My plan is to replace the flooded coach battery in a Class B RV and charge it mostly with the van alternator or shore power converter through a DC/DC charger. I've already got the OverKillSolar BMS and have worked out the settings for it and the Renogy Charger. Now I'm considering adding a fold-up 100W panel and charge controller just for those cases when I am boondocking a little longer than the capacity of the new coach battery.

I've been thinking a 1206AN Epever would be the correct charge controller for a 120 watt panel, but I'm worried the user settings will disappear every time I pack it up and it is no longer connected to power. Why not just set it to Gel with the basic user interface on the screen? Based on the conversation above and the values in the manual for this battery type setting, it would seem to fall in a safe zone for the new LiFePO4 battery in a middle SOC.

From the Epever manual:

system
Battery type Voltage
Gel
Over Voltage Disconnect Voltage
16.0V
Charging Limit Voltage
15.0V
Over Voltage Reconnect Voltage
15.0V
Equalize Charging Voltage
——
Boost Charging Voltage
14.2V
Float Charging Voltage
13.8V
Boost Reconnect Charging Voltage
13.2V
Low Voltage Reconnect Voltage
12.6V
Under Voltage Warning Reconnect Voltage
12.2V
Under Voltage Warning Voltage
12.0V
Low Voltage Disconnect Voltage
11.1V
Discharging Limit Voltage
10.6V
Equalize Duration
——
Boost Duration
120 min


Thoughts?

I don't know the "new AN" controller at all, and it does seem to have some unhappy users within the forum. On my older "BN" Series Controller, you are forced to choose between "Gel" preset (or other presets) versus "Custom". I feel that 14.2V maximum charging Voltage is maybe a bit to low for proper cell balancing (that's 3.55V average cell voltage, but if BMS is allowing up to 3.65V - the default value for most pre-programmed "LiFePO4" BMS systems, then one cell could be left significantly "lagard" while the others ones rise up to the full 3.65 value). I personally feel that 14.5V is the sweet spot, 14.4V is also pretty good IMO. BB's recommended value of 14.6 definitely charges a tiny bit faster, but it pushes cells all the way up to the limit.

As an interesting compromise, which I have not yet tried myself: Full balancing Voltage could be maybe assured by setting "Equalize Voltage" as14.6V, for a maximum of only 30 minutes - and using a slghtly Boost Value most of the time (14.4 or 14.5V).

Float Voltage is between a rock and a hard place. You don't want to have your LFP batteries at 100% SOC *all the time*, that hurts lifepspan. But you also don't want phantom loads "eating them up" all the time, and the critical value "Boost Reconnect Voltage" must be below Float Voltage. I think that a relatively low "Float Voltage" of 13.5 or 13.6V still lets some recharging energy back into the batteries when the sun is shining, without pulling the batteries all the way back up to "Boost Mode" when power isn't being consumed. But that's with the assumption that Boost Mode is terminated only by the Duration Timer and is NOT also terminated by the battery pack reaching "Float Voltage".

BattleBorn's recommendations imply that "Boost Mode" (a CV charging mode, further limited by the maximum capabilities of the PV and charger current Maximum) is terminated only by time. "Boost Duration" and "Boost Reconnect Charging Voltage" are the main parameters the Ep-Ever offers to control Boost Mode". In those GEL defaults, it must be possible to fully balance the cells (at maximum Boost Voltage, with current falling to nearly zero) in only 120 minutes, from "Boost Mode" starting point of 13.2V. In "Boost Mode", my own battery bank charges at 14.5V for nearly an hour AFTER full 14.5V charging Voltage has been reached.

 

[RStone13]

If I understand it correctly? Boost runs until you reach that setting. Then boost duration/timer is absorb mode. Then when that setting ends it will go to float and stay in float until it reaches boost reconnect or a new day will start the process again

 

[time2roll]

I believe Charging Limit Voltage is a cap on temperature compensation adjusted values to protect connected devices. I assume temperature compensation has been disabled and I would set the Charging Voltage Limit at maybe 0.1 above the Bulk/Boost value. I would also disable equalization or set same as Bulk/Boost.

 

[john44066]

There is a good writeup on Solacity.com at this link: https://www.solacity.com/how-to-keep-lifepo4-lithium-ion-batteries-happy/ at this link there is a cheat sheet on the 12 volt charge settings for LiFePO4 batteries.

 

[MorganCarey]

This thread is absolutely awesome. I have been struggling with our 4210AN here as I try to find decent settings to input into the parameters page. I'm quite certain, that with this discussion thread, I can finally get this sorted and tested before I install at our cottage this spring.

Big thank you to Gator for literally writing my own post for me. When I read your original post, I kept thinking... 'yup' 'yup' 'same' 'uh-huh' 'yup. hahahaha

AND THEN big thank you to Mike for 'decoding' the settings for us. Dude, have a virtual beer on me.

honorable mentions go to john and rick for the added input.

I'm gonna attack this tomorrow morning in the shop with a big coffee, and hopefully get this crap up and running so I can do some testing.

 

[TheeDude]

Hello!
Really awesome thread this, but I have some questions.
I read the link that john44066 linked and it was really good, but it feels like something is odd, or I have missed something when setting upp my system.

I have a Epever Tracer 2210an, with a Lifepo4 100ah battery from belluna.eu
And I have a Raspberry pi that are connected to the RS485 connector and it uses Grafana to do some logging so I can see what is happening.

Datasheet of the battery:

https://belluna.eu/wp-content/uploads/2020/12/12V-100Ah-Datenblatt-Batterie.pdf

And here is the specification of the cells

https://belluna.eu/wp-content/uploads/2020/12/3.2V100AH-Datenblatt-Zellen.pdf

I think that the battery voltages varies/fluctuates pretty much, I can see it charges up to 13.8 and sometimes up to 14.5V and it stops charging, it goes down to 12.6-12.8V, which is lover than the resting voltage "at night" it seems to go down to 13.3-13.4V at night when no charging is on.

The battery is new, and installed 3 days ago, I have a couple of logs from last year when I had a lead-acid battery and the voltages there seems to be more stable..

Please look at my pictures and calm me down if everything is normal, this is my first lifepo4 battery.
Theese logs are from a day with strong sun nearly all day.

Here are my parameters:


Two pictures with battery voltages with lifepo4


And solar power from that same day


Last years log with lead-acid battery


And some bonus pictures, some installation pictures in my caravan..