Trouble with calibrate SoC EP500Pro

Hey everyone,
like suggested i do two full cycles on the EP500Pro, charge slowly by AC, but still have SoC jumps in the percentages. Its like 93% really quick goes to 95% (like minutes) and then jump to 100% and quits charging.

Since i do the full cycles, is there any way to “reset” the BMS without reset the whole machine? I would like to keep my production values.

Current Firmwares:
IOT: v9041,03
ARM: v4039,05
DSP: v4038,07
BMS: v1020,01

If the serial number is needed, i would write it via pm.


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did you discharge with a constant load until the EP500 switched off and then charge it via the grid?
I had exactly the same problem and was able to solve it this way

Hi @Marcus,

continous discharge isnt that simple for a battery that big. I tryed to be on a constant level with discharge my unit with other powerstations, but it wasnt 100% steady.

Recharge the unit with 2A from the AC Oultet. So it charges over 10 Hours from 0% to 100%, then i notice this jump again. It was quit better than before. I think it was on like 85% already, but still there.

Thanks for your answer

Hello Erik,
I think the continuous load when unloading is important. I used a fan heater with 1.5 kW of power.
I charged it then with 5A…

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hmm could be.

@BLUETTI @BLUETTI_CARE You may have something to add here?

@Selfmadestrom In this case, I’m sorry I don’t have other suggestions except to repair it.

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Any news about this problem?
The same her again and again…
Very frustrating….

I did calibrate it a couple of times since that. Its getting better but is not completly gone.

The problem with this unit is, its really heavy and not easy to send to repair.

what do you mean by not completely gone? What did Bluetti say about that? The device size is not a problem if you still have the pallet and box. The part was also delivered to you. I definitely don’t agree with that. Let’s see how this goes. I actually wanted an EP600 system in the spring, but I’m not so sure anymore. You always read about problems that can’t really be solved… Marcus

The official answer to this is, when two cycles dont solve the SoC Problem, it needs to repaired. For my Part, i didnt send it in. The SoC not jump from 60 to 100 anymore. Its more like 95 to 100. So its okay for me

ah ok, I understand.
I thought the size of the device would stop you from having it repaired. This is how I read what have written…

Initial this was the case. But in the meantime, i could correct it myself. So no real need to send it in

You wrote to me a few days ago that you have two EP500 PRO.
Is the problem on both of your devices?

Yes. Not at the same time but i had to recalibrate both units at some point

what do you mean at one point you have to calibrate?
The area where the problems occur is now not stable at 95-100%.
That’s how I understood you. The fact that the error occurs on both devices shows that it is a general problem. It’s certainly in Bluetti’s interest too
find a solution here.
We will see…

I mean that there isnt a fixed point where this happend but there will be for sure

ja aber das ist doch Mist und nicht zufriedenstellend, oder?

True, but that isnt a issue thats exclusive to EP500Pro or Bluetti in general. Its just really difficult to get a precise SoC from LifePo4 Batterys.

Mensch Erik,
man könnte meinen Du arbeitest für Bluetti :-)
Hats Du selbst schon Erfahrungen beim DIY Bau von Speichern?
Das geht eigentlich mit einem entsprechenden Shunt recht genau.
Das schein eher ein generelles Problem an dem Sytemaufbau von Bluetti zu sein. Und da sollten wir nicht locker lassen und solche Probleme aufzeigen und eine Fehlerbeseitigung zu verlangen.
Oder wie siehst Du das?

Meine Aussage war eher auf andere “Komplettsysteme” von der Konkurrenz bezogen. EcoFlow hat zum Beispiel ähnliche Probleme.

Mit DIY hab ich keine Erfahrung.

Fehler mit dem SoC werden ja teilweise durch Firmware behoben, allerdings schätze ich mal dass dies nur so eine Art Kalibrierungsdateien sind.

Sofern es nicht auf die Hardware zurüclzuführen ist, wäre es natürlich sehr wünschenswert sowas beheben zu lassen. Wie du schon richtig sagst, muss natürlich dem Hersteller ein Problem aber auch bekannt sein, damit es gelöst werden kann. Ich glaube nicht, dass für 2 Leute die schreiben, dass sie ein Problem haben, eine extra Firmware entwicket wird.

@BLUETTI_CARE Is there any Firmware for the EP500Pro to correct the SoC or a firmware i can test?