LiFePo4 charge problem after reassemble. Any help?

[LadyRover]

PARTS

3x Trina Solar Vertex S 400w Panel

1x Rutland 1200 Wind generator


3x Epever Tracer 4210 AN MPPT 40A

1x Waeco Perfectcharge MCA 1250 50A


1x Daly 400Amp (non smart) BMS


1x 840Ah LiFePo4 12V battery pack, build with 12x 3.2V cells

1x Lead acid 12V starter battery


1x Flamezum 2000W/4000W True sine inverter


DESCRIPTION

System was working fine but got disassembled at ¾ charge status and reassembled after 3 month shipyard visit.

Cells were measured before reassembly and all measured 3.2V.

System was completely discharged to set capacity measure to zero.

Than charged with Waeco at dock until no more change in Voltage.

Then charge capacity set as 100%.


Now afloat without external charge sources except wind, solar and if need be generator.


Lead acid battery is only connected to Rutland turbine and engines via exit 1.

Rutland exit 2 is connected to LiFePo4 charge busbar.


PROBLEM

Charge indicator says 60.8% full, 12.98V.

When 1200W kettle is run from inverter, voltage drops rapidly. This never happened before dissassembley.

Solar panels show 38V but deliver only 0.5-2 Amps each at charge exit of Epever.

Epever settings are the same as the ones used for 2years before disassembley.

When charging via Waeco with generator about 25A go in.

We never let the Waeco on over extended periods. It is just used to charge to about 80%. No float charging with it as we aware that LiFePo4 don't like that.

All charge sources are turned off manually when battery charge is at about 80-85%.


QUESTIONS

Why does the LiFePo4 battery not take in the Solar Power?

Why does the voltage drop now when we start the kettle, we used to be able to cook dinner easily with a 2000W hot plate.

How can we fix the above?

 

[AnarchyJet]

Sounds like a loose or high resistance connection in the battery or wiring. I've seen cables on boats rot on the inside and look perfectly fine on the out side. Check every connection

 

[LadyRover]

Thanks I went through that already...

 

[Texas-Mark]

Than charged with Waeco at dock until no more change in Voltage.

Then charge capacity set as 100%.

Sounds like it was not charged to 100% if you were going by voltage change.

 

[S Davis]

At 12.9 volts you are at about 20% SOC.

 

[Supervstech]

Get a piece of paper a pen and a volt meter.
Measure the precise voltage of each cell to 3 decimal places and write it down start at main negative, and go to main positive.
Report back here your results.

 

[LadyRover]

Get a piece of paper a pen and a volt meter.
Measure the precise voltage of each cell to 3 decimal places and write it down start at main negative, and go to main positive.
Report back here your results.

Thanks you (and the others).

Will do that tomorrow morning.
Two questions though.
Should I switch charge and discharge sources off while doing so?
Do I need to disassemble (remove all busbars and wiring) everything for that? I hope not but fear so..

 

[Texas-Mark]

Should I switch charge and discharge sources off while doing so?
Do I need to disassemble (remove all busbars and wiring) everything for that? I hope not but fear so..

Yes for the first
No for the second.

I really think the issue is that you never fully charged the battery. The difference between 40% and 99% is only about .6V
I would just put it back on a charger and wait until you are at about 14.2V to 14.4V.

 

[LadyRover]

Yes for the first
No for the second.

I really think the issue is that you never fully charged the battery. The difference between 40% and 99% is only about .6V
I would just put it back on a charger and wait until you are at about 14.2V to 14.4V.

Thanks. Lying awake while I read this.
Any thought why it takes charge from the Waeko/Genset but not from Solar?
If it needs more charging now I'd need to use the Waeco/genset.

Before disassembley it charged well via Solar. No change in Epever parameters.

 

[Texas-Mark]

Not sure about your wind generator, but you only have 1200W of solar for a 840Ah battery. Even your generator at 25A into the battery would take quite a while to fully charge it if it was fully discharged. As for why the solar charge controller is not supplying more than 2A, I don't know.

 

[LadyRover]

Here the cell measures and more.

Cells were measured with all charge and discharge sources off. Main busbar were connected. Cell closest to negative measured first.

One 3.315V Two 3.315V Three 3.315V Four 3.313V Five 3.313V Six 3.312V Seven 3.313V Eight 3.314V Nine 3.315V Ten 3.313V Eleven 3.313V Twelve 3.313V

Following this I measured with all charge and discharge sources off as follows:

Multimeter across main battery poles: 13.232V
Battery indicator:
13.23V 58.6% charge
Epever 12V Outlet at unit:
13.23V Charge symbol 70% full

Then I measured again with Solar and Wind on. Discharge is off. It's a sunny day, but due to the desert dust in the region around Malta the panels are not 100% clean.

Measures:
Multimeter across main battery poles: 13.6V

Battery indicator:
13.83V 58.7% charge

Epever 12V Outlet at unit:
14.10V Charge symbol almost full
Delivering 7.5A per panel

Next I measured with still all discharge sources off but all charge sources on, including the Waeco via Genset. Full sun, panels semi clean, no wind.

Multimeter across main battery poles: 13.9V

Battery indicator:
14.40V 60.1% charge +22A

Epever 12V Outlet at unit:
14.4V Charge symbol almost full
+0A

Attached our Epever settings. We used them before successfully they did not change.

THEORY
The Epever "thinks" that the battery is fully loaded when solar is switched on, but battery is actually not full. This because it reads 14.1V at its 12V Outlet when the Multimeter across the main poles reads 13.6V.
Should we change the Epever settings to accommodate that?
If yes, which setting.
Attached a screenshot of the Epever settings (click on the image to see it better) we use and have used successfully in the past.

I did touch all connections, nothing warm, nothing loose, wiring looks good, no corrosion visible.

I'm currently charging with the Waeco/Genset. The Waeco is not a LiFePo4 charger but we use it to "manually" top up when the battery is low. We never leave it on.
Plan to let the Waeco run until the Battery indicator says 95-100%. Even if it's annoying to have to do it. Good plan?
Question remains if it really full then. How can I judge/measure this?

Hope this helps.
I do wonder if something might have been connected wrongly when reassembling.
Thanks for your help!

 

[LadyRover]

Additional info, just switched the genset off as well as all discharge sources:
Epever Battery Outlet13.6V 1A per Panel

Full sun.

Batterie Indicator 13.56V
Charging +1.67A
SOC 66.8%=561Ah

When the Waeco is running I get 20A in. It's supposed to deliver up to 50A.

 

[Supervstech]

Remember, the pv can only output what is being drawn from the system. It cannot push available amps, only provide load.
13.6 is near full, ampdraw will not be much.
Turn on a heavy draw appliance, output should increase.

 

[LadyRover]

Remember, the pv can only output what is being drawn from the system. It cannot push available amps, only provide load.
13.6 is near full, ampdraw will not be much.
Turn on a heavy draw appliance, output should increase.

Very true, and yes I see that happening. Including a voltage drop, which obviously leads to the higher amp draw then.

How do I charge to the 14.2-14.4V suggested earlier in post 8 with my solar then?
What do you make out of my Voltage readings for the cells?

 

[RV8R]

Remember, the pv can only output what is being drawn from the system. It cannot push available amps, only provide load.
13.6 is near full, ampdraw will not be much.
Turn on a heavy draw appliance, output should increase.

I had to “learn” that.

My 600W array Solar Cabin system ( note AGMs & temp controlled );





@LadyRover

Depending upon your equipment, the history can be very helpful on diagnosis.

Above is some old history of my Solar Cabin. You can see when I am not there & to what @Supervstech wrote ,,, it is only recording what is “provides” to the batteries ,,, not what it could have provided ,,, or actual not potential

 

[LadyRover]

I had to “learn” that.

My 600W array Solar Cabin system ( note AGMs );

View attachment 205292

View attachment 205293

@LadyRover

Depending upon your equipment, the history can be very helpful on diagnosis.

Above is some old history of my Solar Cabin. You can see when I am not there & to what @Supervstech wrote ,,, it is only recording what is “provides” to the batteries ,,, not what it could have provided ,,, or actual not potential

Unfortunately I don't have a history.

Still, I do know that we easily had full batteries every day before disassembley. We could cook dinner without problems.

We are located in the southern Mediterranean so, plenty of sunshine.

The battery does take charge 20A from the Waeco, but not from the Solar which seems weird. Should we modify our Epever settings?

 

[RV8R]

Unfortunately I don't have a history.

Still, I do know that we easily had full batteries every day before disassembley. We could cook dinner without problems.

We are located in the southern Mediterranean so, plenty of sunshine.

The battery does take charge 20A from the Waeco, but not from the Solar which seems weird. Should we modify our Epever settings?

I have Victron equipment & do not have experience with your stuff & still learning lots. I was only attempting to state I also had to “learn” about what was actually happening is not what the solar system was capable of providing ,,, That was an important “perspective” for me to learn so I was not chasing ghosts per say.

LFP are a different animal than AGMs; If your LFP are not getting to 100% SOC & they were before then I would think;

1. Diagnose the % SOC accurately & verify
2. See if there are any physical issues with connections
3. Check BMS settings are correct
4. Check charger settings are correct

I have zero LFP experience, so you will get much better help from other experienced forum members.

Many times, “connections” can “look” good, but are no good. A small amount of corrosion or wrong torque can be a problem. Diagnostic of each cell as others are suggesting might point you towards a bad connection, or possibly an imperfect cell.

Sorry I can’t be of much more help than that.


A 2nd thought; Battery Monitors can be liars. If not setup & constantly reset the % can drift. So your batteries have to be “verified” independently from the % on the screen

 

[RV8R]

Another thing;

I know you stated this & are aware, but I am having a hard time understanding your other charger that is not ment for LFP ?

User manual Waeco PerfectCharge MCA1250 (English - 464 pages)

Manual Waeco PerfectCharge MCA1250. View the Waeco PerfectCharge MCA1250 manual for free or ask your question to other Waeco PerfectCharge MCA1250 owners.

www.manua.ls

The only manual I can find is almost 500 pages & full of advertisements that keep popping up, so it’s very frustrating trying to read.

My point is if this charger cannot be altered to properly charge LFP & your BMS does not control the charge being provided, I can’t see that being an environment that is good for your batteries.

I believe for these DIY simple systems, the equipment being utilized should match the required parameters. I like chargers that can be user programmed for profiles, but the battery manufactures should be dictating/sanctioning.

My philosophy in design, is to understand what the battery manufacturer wants for charging & then provide those charge parameters. So you either believe this is important, or you do not. If you do believe it is important, you would have to walk me thru The Logic of using this Waeco Charger that is seemingly not for LFP ?

Do you know the voltage of the Waeco & do you monitor this charge voltage & amperage when charging it with the Waeco ? Has it ever gone into Absorption?


On the Solar side;

3x Epever Tracer 4210 AN MPPT 40A ,,, are these “networked” ?

If the answer is “No” have you tried to disconnect 2 of them so only one is attempting to charge at a single timeframe ? You could try / test out all 3 solar charge controllers “individually” to see if there are differences.

Solar chargers ( my very basic understanding - which very well could be wrong );

Charge the battery
Interogate the battery bank ( hey where ya at SOC ?? )
Then continue to charge or don’t

Parallel 3 solar chargers that “don’t talk to each other” when they interrogate the battery are actually interrogating the voltage of the system @ the time or possibly the voltage of the other 2 or the highest solar charger.

 

[RV8R]

You could use a bus bar here ( 5 lugs );

 

[Supervstech]

What are the charge settings on the pv controller?