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LiFePO4 settings for EPEVER 40a 4210an - parameter error

starchy

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i tried these settings:


but i keep getting parameter errors. i'm running 4 12v 170ah each LiFePO4 batteries from bigbattery.com in parallel. running 2 epevers, 6 solar panels each.
 
When you set "user" battery parameters, the order in which they appear (on the MT-50) is somewhat different than the order in which you must set them.

"Over-Voltage Disconnect" must always be highest. IIRC, it is the first parameter which is presented to you. But you cannot change it to a lower value than "Bulk Charge Voltage" OR "Equalize charge Voltage". You're probably getting bitten by "equalize". You must go forwards on the MT-50 pushbuttons (keep pressing "OK") until you reach those parameters first. Set equalize == bulk, at maybe 14.4V, then go back to reduce your "OverVoltage Reconnect" and OverVoltage Disconnect" values.

"Overvoltage Disconnect" > "OverVoltage Reconnect". (Maybe 14.7V for the first of those, 14.6 for the second). Change these LAST.
Then "Equalize" >= "Bulk" (set them the same, maybe 14.4?) some people use lower values.
Then "Float" must always be greater than "Boost Return", both must be less than "Bulk".
 
i changed equalize first and that worked but i still get a "para error" when i try to lower my over voltage disconnect
 
You have to be logical about the settings for the load terminals, for example, ' low volts reconnect' must be higher than 'low volts disconnect'

Only the values below effect charging, all the rest retate to warnings or the load outputs, typical lithium values are shown

Equalise charge volts for lithium make the same as boost volts
Boost charge volts 14.0 to 14.4
Float charge volts 13.35 to 13.5
Equalise duration 10 minutes
Boost duration 10 minutes

Mike
 
here are my current settings. i think the only things i've been able to change thus far are to "user" from flooded or whatever the default was (there's not lithium setting on this iteration) and batt. ah to 170ah (the amp hours of any 1 of the 4 batteries. should i be setting it to the total of the battery bank instead?). i'll try some of the suggestions (like setting the temp comp coefficient to 0) and report back.
 

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here are my current settings. i think the only things i've been able to change thus far are to "user" from flooded or whatever the default was (there's not lithium setting on this iteration) and batt. ah to 170ah (the amp hours of any 1 of the 4 batteries. should i be setting it to the total of the battery bank instead?). i'll try some of the suggestions (like setting the temp comp coefficient to 0) and report back.
Does your Epever allow you to change settings to LiFePO4 with the MT-50, or does the manual tell you to use a PC or a phone APP?

Page 21: NOTE: MT50 don’t support the lithium battery parameters.
 
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there's no such setting using the mt-50. unsure how i'd go about it otherwise.
 
just replied to the other thread as well,

@SOK-MIN said Equalize at 14.4v and boost to 14.6, however Equalize voltage has to be high-than or equal-to boost voltage with Epever, that's why you're getting an error.

If you look at the programming rules on Page 18 of the manual it will give you all the info. I think the lithium specific settings have to be accessed via the PC software.

There's a video here on setting up the software
 
Visit Epever.com

1. Download the manual.
2. Download the software for your product.
3. Connect the RS485 cable to the controller and the PC.
Proceed with installing the proper settings for your batteries. :)
 
Does your Epever allow you to change settings to LiFePO4 with the MT-50, or does the manual tell you to use a PC or a phone APP?

Page 21: NOTE: MT50 don’t support the lithium battery parameters.
That note merely means that the MT-50 doesn't provide a canned, selectable profile for "Lithium". Using battery profile "User", you set anything you like - limited only by the page 18 rules which pollenface and I have been talking about.

I don't own the "AN" controller in question here, but I have done FOUR lithium installations on Tracer "BN" controllers - all via MT-50 alone.
 
here are my current settings. i think the only things i've been able to change thus far are to "user" from flooded or whatever the default was (there's not lithium setting on this iteration) and batt. ah to 170ah (the amp hours of any 1 of the 4 batteries. should i be setting it to the total of the battery bank instead?). i'll try some of the suggestions (like setting the temp comp coefficient to 0) and report back.
I would drastically reduce that "Equalize Time", because EpEver runs at the Voltage for the full length of the timer - it does NOT terminate "Equalize" with reaching "float Voltage". Mine is actually set for 1 minute, and the Voltage is merely equal to Boost (not higher).
 
I DO have one and have programmed and tested with it extensively.
IMO the button settings for parameters is beyond frustrating and confusing. I would encourage asker to source the proprietary RS485 cable and connect to it with a laptop or tablet. The programming window and app is much easier to work with.

AFAIK the minimum time for boost is 10 minutes. For a lower boost voltage a longer duration can be used, for a higher voltage a shorter duration should be used.
Equalize should be set to zero - is not used with lifepo4.

What other questions were there?

EPEver app parameters app:

 
Equalise is only used for flooded lead batteries where a higher voltage than normal is applied. For lithium set to the same as boost volts and duration as short as the programming allows.

The boost duration , called absorbtion dutation/time by most chargers, is not really needed for many solar charging systems with lithium and needs to be set as short as posible.

Lithium charging needs temperature coefficient set to 0.

Excessively high charging and float voltages with long boost duration will overstress lithium batteries and may lead to reduced service life.

Mike
 
Off-grid Garage demonstrates absorption time with a low charge voltage, say 13.6 or 13.8V. Here the pack needs some time at that voltage level for charging amps to taper off. Once they do the pack is fully charged. It's the last 8-10% of capacity.

If you use a higher charge voltage, then charging should terminate at a low current, it's already reached full charge and no further absorption time is needed.

Either way works - you get to 100% SOC, the lower rate just takes longer. And most charging systems don't terminate charge based on tail current.

Check out his vids...quite revealing and he's a hoot. Lots of extensive testing with prismatic cells. Other formats can vary.

I wished I would have found him before I spent so much time discovering the very same things he did. But his tests were much more elaborate. I could tell what was going on by comparing BMS, coulomb counter, and charge controller program. I also learned a lot trying to setup my RV converter/charger, and finally accepted that it would require a manual control for fast charging - set it to 14.1V and when current gets to 10-12A just shut it off. Battery is 99.9% charged. I'm not worried about the last few percent of capacity. And I don't want to over-volt or over-charge my expensive lifepo pack.
 
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talked to the battery manufacturer about my current settings as well as the SCC manufacturer and figured i'd upload their responses here for the historical record. i suppose i'll replace both charge controllers with one rated for the total amperage at some point. hope they'll be okay until then.
 

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¯\_(ツ)_/¯ the battery representative seemed to think the settings were okay with the exception of the over voltage disconnect which i can't set lower than 16v, at least not through the mppt. i'll try, at some point, through my pc.
 
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