Why Has My 6-Month-Old "Once Perfect" Solar System Failed?

Just John

Photon Sorcerer
I tried to use the lithium-set 120V 10 amp battery charger that came with the batteries to charge a single (disconnected/isolated) battery. But it is too slow for using the genset. After 6 hours of run time, the voltage increased only from 13.01 volts to 13.16 volts. Or, does that prove it is the battery's BMS limiting the charging?

10 amps at 6 hours and goes from 13.01 to 13.16v sounds like it is charging to me.
It's slow, but it is certainly charging. Used a calculator, and very slightly over 3.2 to very slightly under 3.3, that is a pretty significant charge for LiFePO4. It sounds like it is accepting the 10 amp charge.

So, if I disconnect the lithium batteries and connect the lead-acid 12-volt battery, I also need to reset the Tracer charge controller to SLA, to be safe? Correct?

Yes, I think so, but I don't know much about SLA.

Edit to add, don't try to parallel the batteries until you have charged all three pretty close.
 
Last edited:

HRTKD

Boondocker
Hey John, relax. Things don't add up. No disagreement there. Two different charge rates. In the immortal words of Mark Knopfler, "one of them must be wrong."
cool1.gif


A cell at 3.25v could take a long time to get up to a full charge. I may have watched paint dry faster than that.
 

Just John

Photon Sorcerer
Hey John, relax. Things don't add up. No disagreement there. Two different charge rates. In the immortal words of Mark Knopfler, "one of them must be wrong."
cool1.gif

No doubt. Certainly we have never seen a Chinese battery where the specs "stretched the truth". Or a seller on ebay (yes, sarcasm, trust but verify seems appropriate).

Once you figure out at least one of the specs is wrong, you have to wonder about the rest. Is it 150Ah battery with up to 150 amp discharge? The cables and connector seem like 50 amps. Do the cables on the batteries he has say 8 AWG like the pictures?

A cell at 3.25v could take a long time to get up to a full charge. I may have watched paint dry faster than that.

I can't dispute that a 10 amp charger and a 150Ah battery is akin to watching paint dry.
 

Just John

Photon Sorcerer
(1) Solar controller = EPEVER Tracer 4215BN. From my solar panels' specs when wired series-parallel, I calculated a max of 79.32V and 12.52A possible. Panels are flat mounted, so I would never get that max PV output.

AFTER the failure, I spent hours and finally figured out how to change the Tracer 4215BN to the gel setting. But, I still can't figure out what settings I should use for lithium in the user settings. here and elsewhere. I found several exchanges here, but I got lost in all those numbers which do not match the settings "names" in the Tracer 4215BN/MT50 system.

I'm not sure if the Battleborn settings would be correct, but they are most likely better (I hope you got the MT50, it's apparently much easier than without):


This looks like the manual:


Will has some recommended settings:


12V LiFePO4 Battery w/ BMS:
  • Absorption: 14.5V
  • Float: 13.6V
  • Inverter Cut-off: 10.7V-12V (depending on size of load and voltage drop etc)

5,000+ Charge Cycle Absorption Recommendation
If you want your LiFePO4 cells to last a long time, you can set your absorption to Victron's custom LiFePO4 charge profile recommendation:
  • 12V Battery: 14.1V
  • 24V Battery: 28.2V
  • 48V Battery: 56.4V
You can pull full capacity with the absorption figures above, but the charge rate will be reduced at high SOC.
 

AZRoadrunner

Solar Enthusiast
Jim, like you I'm new to solar, and I'm also in AZ -- maybe we'll meet up sometime (I'm in the Tucson area). I read your first post and would like to give you some words of encouragement: there's a known science to electricity and electronics, but also a healthy measure of voodoo because of variables that can drive us COMPLETELY insane. I've been a certified electronic technician since back in the 80s and a ham radio operator since 1974 -- and that and 25 cents won't buy you a cup of coffee. Solar power is its own electrical and electronic niche filled with unique idiosyncrasies, manufacturers that lie like a rug, and piles of equipment manufactured overseas by vendors who cut every corner imaginable. Like you, I'm learning. Hang in there. Your system will be back up and running -- there's a REASON it's down. I also understand your frustration with making questionable purchases -- today I received two new solar panels from a company that seemed competent -- one is physically fine and tests functionally within specs -- the other was a broken mess in a box filled with glass shards because the flaming idiots who packed the panel used the least amount of packaging possible. I wanted to scream.
 

jesfl

Solar Enthusiast
Everyone, thank you again for the information and the encouragement. It is very much appreciated.

I took yesterday off because I had no response from the battery seller or from the new U.S. sales group that I now believe is directly representing the manufacturer, one way or the other. But I cannot confirm that.

This morning, I am catching up.

I now have a response to the question: "How do you reset the BMS in the batteries."

Their full, detailed answer was expansive: "charge the battery and the BMS will reset".

(1) Does that make sense?

So, I will hook up the chargers again and try to be patient and accept the "slow as paint drying" charging process.

To do so, since I am in the Arizona desert with no shore power, I've found I can run the 10-amp 120-volt chargers off the incoming solar power in daylight. At that rate, IF the batteries are charging, I should have "dried paint" in, what, 3 months or so?

(2) I note the advice that the 3 batteries all need to be charged to the same voltage, i.e. balanced or equalized, or whatever it is called. How close is acceptable? One-tenth of a volt? One-one-hundredth of a volt?

(3) How do I know when the batteries are truly fully charged? Supposedly enough to reset the BMS?

(4) I have been using "about 13.4 volts" as the full charge level for a LiFePO4 battery. Is that the correct "full charge level?"

Next, I'm going to reread everything about setting the EPEVER MMPT solar charger (yes, I have the MT50 remote meter) for LiFePO4 charging. Thanks for all of the suggestions and the Battle Born info. If the batteries really recharge (skepticism here), I'd like to be prepared to reconnect them to the SCC and see if they will actually work?

It would be a miracle if it works.

Jim S.
 

HRTKD

Boondocker
(1) Does that make sense?

Maybe? If it works, great. But why wasn't that working before? I'm skeptical.

(2) I note the advice that the 3 batteries all need to be charged to the same voltage, i.e. balanced or equalized, or whatever it is called. How close is acceptable? One-tenth of a volt? One-one-hundredth of a volt?

I don't know for sure. But in your case, since you're kind of desperate, .1v is close enough, maybe even .2 or .3.

(3) How do I know when the batteries are truly fully charged? Supposedly enough to reset the BMS?

This is where your voltmeter comes in handy. You'll need to check the voltage at each battery.

(4) I have been using "about 13.4 volts" as the full charge level for a LiFePO4 battery. Is that the correct "full charge level?"

If I was fulltiming, I would expect a charge level closer to 14.4v
 

jesfl

Solar Enthusiast
Fast response. Thanks.
Maybe? If it works, great. But why wasn't that working before? I'm skeptical.



I don't know for sure. But in your case, since you're kind of desperate, .1v is close enough, maybe even .2 or .3.

This is very helpful.

This is where your voltmeter comes in handy. You'll need to check the voltage at each battery.

Yes, I've been using my multimeter at the batteries when disconnected.

If I was fulltiming, I would expect a charge level closer to 14.4v
That's a huge discrepancy from 13.4 volts for LiFePO4 full charge to 14.4 volts full charge? I can see 14,4 volts at the battery when the 10-amp charger is turned on. But, when disconnected and testing just the isolated battery, I'm getting a much lower 13.1-13.2 volts right now. To get to 14.4 volts charge then likely is a year of paint drying?

What am I missing? Going outside to test batteries again.

Thank you.
 

HRTKD

Boondocker
That's a huge discrepancy from 13.4 volts for LiFePO4 full charge to 14.4 volts full charge? I can see 14,4 volts at the battery when the 10-amp charger is turned on. But, when disconnected and testing just the isolated battery, I'm getting a much lower 13.1-13.2 volts right now. To get to 14.4 volts charge then likely is a year of paint drying?

What am I missing? Going outside to test batteries again.

All I can tell you is that my 560Ah of batteries will charge up to 14.4v from my 640 watts of PV on a good day of sun, from a 70% state of charge.

It sounds like your batteries are "resting" at a lower voltage than most of us would expect a LiFePO4 battery to go down to after a full charge. However, 14.4 while charging doesn't necessarily mean that the battery is fully charged. It's a bit of a gray area for me. Hopefully someone else can chime in here with a better explanation.
 

jesfl

Solar Enthusiast
Follow-Up: Why Has My 6-Month-Old "Once Perfect" Solar System Failed?

Beginner here. I posted the above inquiry 10 days ago. Many, many helpful comments and suggestions. Thank you to everyone.

I have now tried everything suggested (save one, below) and nothing has worked, including the purchase and installation of a new solar charge controller.

The quick summary is:
-- LiFedPO4 batteries (3 - 12-volt, i50Ah, in use 6 months) will not charge
-- tried charging with genset (+ PD lithium converter), with 120V lithium battery charger from the battery manufacturer, and with the solar system.
-- many responders said "BMS" -- protect mode, reset, etc.
-- U.S. eBay seller of the batteries says only: "full charge the batteries, the BMS will reset." (I do not believe it, but . . . )
-- which brings the vicious circle: -- batteries dead/BMS may not be working -- batteries won't charge -- reset BMS by full charging batteries -- batteries won't charge -- BMS won't reset . . . and downward . . .

I now conclude the 3 BMS units in the 3 batteries are the problem. I pray the cells are not somehow killed?

The one suggestion I did not try (because it is scary to me) was: "Have you tried hooking one solar panel directly to a battery to see if it will charge?"

I recognize it is probably futile (and certainly a hassle to do because of roof-mounted PV panels and the length of wire necessary that I will have to buy, I'll try it if there is a chance it might somehow "wake up" the BMS and allow the batteries to charge?

Solar panel specs: 100Ah; Voltage (Vmp) - 16.77V; Current/Amps (Imp) - 6.26A; Open Circuit (Voc) - 19.83V.

If connected directly into a battery with no controller, will the above panel kill the battery completely?

Is there any chance it does anything positive -- either awaken the BMS and/or charge the battery?

Someone wrote: "What do you have to lose?" True. But, I do not want to completely kill the cells if there is any chance they still might be used in a battery re-build with a new BMS. Absent any other option, I might have to resort to that radical-for-me attempted solution, frightening as it is to me.

Now having been without a working solar system while boondocking for 6+ weeks (lost count), I am truly desperate.

Thanks to anyone and everyone for any last thoughts.

Jim S
 

HRTKD

Boondocker
If the converter wouldn't charge the batteries, then I don't see any hope that connecting a solar panel directly would charge the batteries either. The PV voltage is much higher than what would normally be acceptable as the maximum charge voltage for a LiFePO4 battery.
 

Just John

Photon Sorcerer
Follow-Up: Why Has My 6-Month-Old "Once Perfect" Solar System Failed?

Beginner here. I posted the above inquiry 10 days ago. Many, many helpful comments and suggestions. Thank you to everyone.

I have now tried everything suggested (save one, below) and nothing has worked, including the purchase and installation of a new solar charge controller.

The quick summary is:
-- LiFedPO4 batteries (3 - 12-volt, i50Ah, in use 6 months) will not charge
-- tried charging with genset (+ PD lithium converter), with 120V lithium battery charger from the battery manufacturer, and with the solar system.
-- many responders said "BMS" -- protect mode, reset, etc.
-- U.S. eBay seller of the batteries says only: "full charge the batteries, the BMS will reset." (I do not believe it, but . . . )
-- which brings the vicious circle: -- batteries dead/BMS may not be working -- batteries won't charge -- reset BMS by full charging batteries -- batteries won't charge -- BMS won't reset . . . and downward . . .

I now conclude the 3 BMS units in the 3 batteries are the problem. I pray the cells are not somehow killed?

The one suggestion I did not try (because it is scary to me) was: "Have you tried hooking one solar panel directly to a battery to see if it will charge?"

I recognize it is probably futile (and certainly a hassle to do because of roof-mounted PV panels and the length of wire necessary that I will have to buy, I'll try it if there is a chance it might somehow "wake up" the BMS and allow the batteries to charge?

Solar panel specs: 100Ah; Voltage (Vmp) - 16.77V; Current/Amps (Imp) - 6.26A; Open Circuit (Voc) - 19.83V.

If connected directly into a battery with no controller, will the above panel kill the battery completely?

Is there any chance it does anything positive -- either awaken the BMS and/or charge the battery?

Someone wrote: "What do you have to lose?" True. But, I do not want to completely kill the cells if there is any chance they still might be used in a battery re-build with a new BMS. Absent any other option, I might have to resort to that radical-for-me attempted solution, frightening as it is to me.

Now having been without a working solar system while boondocking for 6+ weeks (lost count), I am truly desperate.

Thanks to anyone and everyone for any last thoughts.

Jim S

1. Won't kill the battery with those specs. It will drop the output voltage of the solar panel to the same as the battery if directly connected. Won't provide optimum charging, but won't hurt the panel or the battery.
2. When some BMS "reset", they basically provide no voltage to the input/output, and the solar charge controller unless designed for LiFePO4 will think there is no battery and decline to charge.

From your previous posts, it sounds like they were accepting a charge, although due to the limited current, it was obviously slow.
What part of Arizona are you in, I'm in Mesa, and if you are within a couple of hours drive I could attempt to assist.

I have a Victron charger (25 amp, 12 volt), a spare Rich solar charge controller (40 amp, mppt, max 100 volt PV input), a 40 amp power supply (15 volt max), lots of connectors, meters, crimp tools, cable, etc. We can easily figure out if it is the BMS, solar charge controller, or finally the BMS and/or cells. So at the very least, you could fire up your generator and try charging at 40 amps or less and see if the batteries are accepting a charge. The power supply has an amp output display, so you would know right away if they are accepting a charge, wouldn't even need a meter (I of course also have a clamp ammeter). I also have other power supplies, so if they do accept a charge, depending on generator size, we could charge all three batteries simultaneously (just some with less current).
 

jesfl

Solar Enthusiast
HRTDK:

Thank you. Might try it. But, sounds like it likely will do nothing, IF the problem is the BMS.

I wrote "converter" as won't charge, but not honestly sure. It did charge the lithium batteries previously, before they went completely dead. When I could still start my genset with the batteries, I tried the PD lithium converter and it seemed to charge a little, but very slowly. Now, since the batteries are not useable, I can't even start the genset without hooking up a cheap Walmart SLA battery I bought instead of the lithiums.

Been wondering about how to wire in the SLA battery so I could start and run the genset through the WFCO power panel and that PD converter to try to charge the lithium batteries that way. Really don't know how to do that. The other option is to go to an RV park and hook up to shore power there to try the converter charge that way. (Ugh.) As a newbie, I really didn't even think of that possible solution until last Friday as I struggled with all of this.


Just John:

Thank you, also.

To your point #2. Interestingly, I have just realized when trying the new/second SCC I purchased, that the SCC reads the batteries as 10.5 volts. If I turn on the PV panels, the controller immediately reads that the batteries are FULL? Is that the BMS causing that? Whatever is causing the controller to read "full," I assume, is the reason the batteries won't charge?

Now, I admit I don't really understand what you are saying the way BMS reset, given the one seller's (very limited) "charge until full and the BMS will reset" instruction.

By the way, again this morning I checked and the lithium batteries read 13.37 volts disconnected from everything using my multimeter. Then, connecting them to the system, the controller reads 9.5V to 9.9V and then settles at 10.5 volts. In a separate, limited post, I asked the question why, how is that possible, and no one was able to explain.

The batteries would only accept a charge from the 120V lithium battery charger that came with them from the manufacturer. It was very slow (10 amp chargers). Then finally, after several days of charging, they apparently hit some sort of maximum and stopped charging any further. One at 13.37V, one at 13.31V and the last at 13.29 V. Won't go any higher. Again, multimeter reading completely disconnected from everything.

And, thank you for that offer. I'm in the Yuma area, but a week or so from departing for various reasons. If there's no progress by then, I might just head your way. I will appreciate another more-knowledgeable-than-me mind on the problem.

FYI, I previously looked at the Rich 40 amp SCC, but bought my second one from Windy Nation (TrakMax 40amp) because they have been so helpful and supportive of me. They look identical, except for the color of the plastic case. Likely the same Chinese manufacturer, although specs could be different.

It seems to me the key is the BMS and getting those to "reset." Since I can't get any help from the eBay seller from whom I bought last year (and the new sellers of the same batteries are not really interested in helping), I'm pretty much dead in the water without that reset.

Thank you again. I'll let you know.

It is very frustrating.

Jim S.
 

Forbisher

Փփքխմպձժճֆըվմ
40A SCC is only good for about 560 watts panels at 12V

EDIT: 800 watts panels into 12V battery is 66A but you only have 40A

You are charging a 12V 450Ah LFP battery.

Maybe remove the shrink wrap from a battery to see what is in there.

HRTDK:

Thank you. Might try it. But, sounds like it likely will do nothing, IF the problem is the BMS.

I wrote "converter" as won't charge, but not honestly sure. It did charge the lithium batteries previously, before they went completely dead. When I could still start my genset with the batteries, I tried the PD lithium converter and it seemed to charge a little, but very slowly. Now, since the batteries are not useable, I can't even start the genset without hooking up a cheap Walmart SLA battery I bought instead of the lithiums.

Been wondering about how to wire in the SLA battery so I could start and run the genset through the WFCO power panel and that PD converter to try to charge the lithium batteries that way. Really don't know how to do that. The other option is to go to an RV park and hook up to shore power there to try the converter charge that way. (Ugh.) As a newbie, I really didn't even think of that possible solution until last Friday as I struggled with all of this.


Just John:

Thank you, also.

To your point #2. Interestingly, I have just realized when trying the new/second SCC I purchased, that the SCC reads the batteries as 10.5 volts. If I turn on the PV panels, the controller immediately reads that the batteries are FULL? Is that the BMS causing that? Whatever is causing the controller to read "full," I assume, is the reason the batteries won't charge?

Now, I admit I don't really understand what you are saying the way BMS reset, given the one seller's (very limited) "charge until full and the BMS will reset" instruction.

By the way, again this morning I checked and the lithium batteries read 13.37 volts disconnected from everything using my multimeter. Then, connecting them to the system, the controller reads 9.5V to 9.9V and then settles at 10.5 volts. In a separate, limited post, I asked the question why, how is that possible, and no one was able to explain.

The batteries would only accept a charge from the 120V lithium battery charger that came with them from the manufacturer. It was very slow (10 amp chargers). Then finally, after several days of charging, they apparently hit some sort of maximum and stopped charging any further. One at 13.37V, one at 13.31V and the last at 13.29 V. Won't go any higher. Again, multimeter reading completely disconnected from everything.

And, thank you for that offer. I'm in the Yuma area, but a week or so from departing for various reasons. If there's no progress by then, I might just head your way. I will appreciate another more-knowledgeable-than-me mind on the problem.

FYI, I previously looked at the Rich 40 amp SCC, but bought my second one from Windy Nation (TrakMax 40amp) because they have been so helpful and supportive of me. They look identical, except for the color of the plastic case. Likely the same Chinese manufacturer, although specs could be different.

It seems to me the key is the BMS and getting those to "reset." Since I can't get any help from the eBay seller from whom I bought last year (and the new sellers of the same batteries are not really interested in helping), I'm pretty much dead in the water without that reset.

Thank you again. I'll let you know.

It is very frustrating.

Jim S.
 
Last edited:

TomC4306

Solar Enthusiast
1. Won't kill the battery with those specs. It will drop the output voltage of the solar panel to the same as the battery if directly connected. Won't provide optimum charging, but won't hurt the panel or the battery.
2. When some BMS "reset", they basically provide no voltage to the input/output, and the solar charge controller unless designed for LiFePO4 will think there is no battery and decline to charge.

From your previous posts, it sounds like they were accepting a charge, although due to the limited current, it was obviously slow.
What part of Arizona are you in, I'm in Mesa, and if you are within a couple of hours drive I could attempt to assist.

I have a Victron charger (25 amp, 12 volt), a spare Rich solar charge controller (40 amp, mppt, max 100 volt PV input), a 40 amp power supply (15 volt max), lots of connectors, meters, crimp tools, cable, etc. We can easily figure out if it is the BMS, solar charge controller, or finally the BMS and/or cells. So at the very least, you could fire up your generator and try charging at 40 amps or less and see if the batteries are accepting a charge. The power supply has an amp output display, so you would know right away if they are accepting a charge, wouldn't even need a meter (I of course also have a clamp ammeter). I also have other power supplies, so if they do accept a charge, depending on generator size, we could charge all three batteries simultaneously (just some with less current).
COULD it be that his BMS is a separate port model? And that is why charging is restricted to 10 amps? And why the charger that came with the batteries was only 10 amp? And when he happened to get peak solar at 76v and 12.xx amps it maybe went into oc protect? Doesn't the fact that he's reading sort of normal volts at the terminals mean the battery is out of protect mode? Been lurking waiting for someone.ore knowledgeable to raise these thoughts but had to at least chime in. Could be all wet...
 

HRTKD

Boondocker
COULD it be that his BMS is a separate port model? And that is why charging is restricted to 10 amps? And why the charger that came with the batteries was only 10 amp? And when he happened to get peak solar at 76v and 12.xx amps it maybe went into oc protect? Doesn't the fact that he's reading sort of normal volts at the terminals mean the battery is out of protect mode? Been lurking waiting for someone.ore knowledgeable to raise these thoughts but had to at least chime in. Could be all wet...

That's as good a guess as anything else. A BMS that has gone silent due to low voltage disconnect would _normally_ need to reach a threshold voltage to come back online. 13.2v or higher would seem to be a reasonable threshold to me. But at this point, the BMS is a black box that we have no way to get any answers out of.
 
Last edited:

rickst29

Solar Addict
Separate from the likely BMS failure or cell failures: For the case of Lithium batteries, your Solar Controller (EPEVER Tracer 4215BN) should be programmed "custom". I use the following parameters with mine:

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 (with 0 duration 'equalization time')
Boost Charging Voltage 14.6 V
Float Charging Voltage 13.6 V
Boost Reconnect 13.3 V
Low Voltage Reconnect 11.3
Under Voltage Warning Reconnect Voltage 11.5
Under Voltage Warning 11.5
Low Voltage Disconnect 11.0
Discharging Limit Voltage 11.0 (irrelevant, if you do not use the SCC "load" port).
Equalize Duration 0 or set as low as possible
Boost Duration 180 minutes

BattleBorn has nearly identical recommendations. A good argument can be made for "Boost Charging Voltage" a bit lower (maybe 14.5V), and "Boost Reconnect" is a hard choice - tending to full charge LFP batteries due to the long boost duration, which you might not want to do quite that aggressively.
 

jesfl

Solar Enthusiast
Thanks again, Gents.

(1) What I think I've learned that a BMS just switches "Off" to go into protect mode?

Or does it still allow that very small "maintenance current" into the battery, i.e., the 1-2 amps I see. (That, then, is 30 days of solid AZ sunshine 8-9 hours a day with no load to charge the batteries back to full and hopefully "turn on" the BMS?)

(2) You wrote: "COULD it be that his BMS is a separate port model? And that is why charging is restricted to 10 amps? And why the charger that came with the batteries was only 10 amp? And when he happened to get peak solar at 76v and 12.xx amps it maybe went into oc protect?"

I have no idea what a "separate port model" is about. But, I do know new sellers of the same battery on eBay now list maximum charging at 100 amps vs. 10 amps in earlier listings (which someone speculated as a typo).

(3) I spent hours and found and tried three different "sets" of programming values for lithium batteries, from Battle Born to Victron to EREVER and several individuals here. None changed anything. It is now programmed within 0.1 of the values you list! For instance, I'm down to 14.5 for charging limit voltage, per Will's longer battery life suggestion. Thank you, your list is another great reference resource.

. . . there oughta' be a way to either hack or blow up an internal BMS so a (better quality and capability) external BMS could take over! I'm just sayin' . . .

I keep hoping for a miracle. Before I tear a battery apart to look inside (truly frightening), I am waiting on a couple of more answers from the current eBay sellers. For instance, I don't know some basic things like: Is a 150 Ah battery 6 cells (instead of 4 cells for a 100 Ah battery)? Are 150 Ah battery cells the same voltage as 100 Ah battery cells (they can't be if there are only 4 cells, right?)? Etc. Real beginner here! Over the weekend, I looked online for a "6s" BMS and could not find any at all. But, there are quite a few 12 volt 150 Ah batteries out there nowadays. I don't understand the battery construction. It is very easy for me to be lost down one of a gazillion rabbit holes in these subjects.
 

HRTKD

Boondocker
Typical 12v LiFePO4 battery is four cells. Each cell being 3.2v nominal.

Not all BMS are created equal. Some are programmable, some aren't. Some are robust, some aren't. Replacing the BMS is certainly doable, but it won't be simple. It's more of a logistics issue than a technical issue because the new BMS isn't likely to fit in your existing battery case.

Separate/Common port is a big discussion. There is a thread on it that can be found here:

 

mikefitz

Solar Addict
Boost Duration 180 minutes
You should review this setting. The charger puts current into the battery until the boost charge voltage 14.6 is reached. It then holds the voltage at this level for the boost duration. That is holding the perhaps fully charged battery at 14.6 volts for 3 hours. This seems a poor method of charging a lithium battery where a fractional C charging rate is used.
Victron for their lithium batteries recommend 14.2 charge voltage, no or a maximum 30 min absorption time, (the boost duration in Epever speak), and a float of 13.5 volts.

It seems to me the key is the BMS
I suspect that the BMS have died. From the picture of the battery, cutting open the batteries does not seem difficult. Testing the cells and replacing the BMs if the cells prove usable, may be a way forward.
It could be using the batteries to start the generator exceeded the current output and caused damage.

There will be four 'cells' in the battery connected in series with a 4s BMS. If the battery uses prismatic cells, the 'cells' may be individual large 150Ah cells or two 75Ah cells in parallel, effectively making one 150Ah 'cell'.
An alternative construction may use a high number of cylindrical cells arranged in parallel groups, making up 4 large 150Ah 'cells' again with a 4S BMS.
If you dismantle the battery carefully perhaps posting photographs as you progress, I am sure there are enough experienced folk on here who can offer guidance.

Mike
 
Top