Reuse batteries from bluetti with external controller

[camaroncito]

Has anyone tried to use the lithium battery blocks from inside of a Bluetti with external controller/computer/inverter?

We live off grid in Panama, and in summer 2022 we purchased 4 EP500 and 8 AC200 to power our home and different buildings. We had first purchased an AC200 Max and used it for 6 months to great effect, so we bought more. Each is a stand alone install with its own panels. The AC200Max stopped working after about a year. So did the other machines … at the 10 to 14 month mark, each machine has shorted out. The tiny yellow fuse connector on the circuit board connecting the solar charge sparked/fired. We have high quality panels, cables, circuit breakers on the cables. It seemed to be a faulty component issue.

We sent photos/videos of our entire installation (including specs of the panels, cable, circuit breakers, etc), and (after many back and forth emails) Bluetti sent us new circuit boards, which we installed, all worked great again, until now they are all dying again. Same issue. I will of course ask that Bluetti send me new circuit boards again, but if it is as difficult as it was the last time when all the equipment was only 1 year old, I expect an issue, and certainly need a longer term solution.

I have $30,000 worth of Bluetti equipment (that is now almost junk), and my estimate is that $20,000 of that is in just the batteries, which should have MANY years of life left in them. I hope to find a way to reuse them with other external equipment. Attached is a photo of the EP500 board with the shorted circuit circles in red. The exact same yellow fuse connector is the point of failure in both AC200 and EP500. In this board, only the bottom fuse fried, so the top one still works, so I can still charge the EP500 at half speed (using one set of 3 panels) instead of at full speed (using 2 sets of 3 panels). But in time, I know the second one will fry too.

NOTE … all the machines continue to accept charge via my gas generator, but that kind of defeats the purposes of having a solar system, no?

Does anyone here have any ideas? No doubt there are MANY people in my same position … a HUGE set of good batteries that need to be reused!

[Snips1]

Hello camaroncito
Sorry for what is happening to your bluettis

You say that you recharge the bluettis (with a faulty solar input) with your gas generator… I think that a simple way is instead of the gas generator to put a hybrid inverter, to which you will connect your solar panels and the hybrid inverter will provide 110V, and you will connect the AC charging cable to it (like for your gas generator).

To illustrate, I am giving you an example of a hybrid inverter below, but you will have to choose the right model in relation to your solar panels (voltage, power, etc.) and the power on the 110V side (I do not have an EP500, I read that the EP500 is limited to 600W when recharging from the AC socket… but it’s quite confusing for me, because I read in the manual that you can adjust the maximum intensity of the current taken from the gride).
solar hybrid inverter

For the AC200max or AC200P, if the solar input is faulty, you can buy a D050S amplifier from bluetti, this allows you to connect the solar panels to it (be careful: 12-60VDC max for the solar input) and recharge the AC200P and AC200max to 500W max with the ac-dc adaptor input.
bluetti D050S
[D050S_User_Manual.pdf (shopifycdn.net)]

Bluetti D050 manual

PS I ask myself the following question: why don’t you try to have it repaired by an electronics technician? even without a plan and diagram, like for example for your EP500 you still have the PV1 input working, it should be easy to test the components on the faulty PV2 input and compare it against PV1, to identify the faulty component ( if a visual inspection reveals nothing) before replacing the fuse

[Selfmadestrom]

Hi @camaroncito
The question that im asking me is, why they broke in such a short time frame. Kill a MPPT Controller isnt that difficult. Make 100% sure that the open circuit voltage dont exceed the max MPPT input.

Overpaneling the Voltage doenst need to kill the MPPT instantly but if a the case happens that way to much voltage was pushed to the mppt, you fry them. Im really sure its not the units. So many broken units in such a short timeframe… im sure there is something in your setup that you might not thing about.

Double check the specs of your panels and how you wire them. I do have a EP500 Pro with 3x 400W Panels per String (Open Circuit Voltage 40V each) which means i use 120V out of 150V. Its also really important to have buffer. Sometimes panels produce a bit more voltage which can have a big impact with 3 Panels in series.

For your main question, im pretty sure its somehow possible to extract some components. Would i ever touch the electronics inside a powerstation? - Surely not!

greetings
Erik

[Snips1]

I also wondered why so many recent bluettis had broken down. In addition to
Selfmadestrom above, I wondered if it might also be related to the apparently frequent thunderstorms and lightning in Panama. But maybe Mr. Camaroncito has already put in lightning protection for the solar panels/DC circuits.