With great frustration a friend gave me an AC200P. The unit starts, the screen initializes, then beeping starts. The fault screen lights up. On screen 5 is the problem, fault #42, BMS over voltage, and fault #43, BMS low voltage. The unit stays on for maybe 15 seconds and then shuts down. The screen shows 100% charge. This fault history goes back three years. SOC shows 100% and voltage is 51.0. How do I fix it? Has anyone encountered this issue and what did you do?
Hi @Philos72, We are concerned that this AC200P might have experienced over-discharge. We recommend charging it for a longer period. If possible, use solar charging or car charging. The displayed SOC100% might not be accurate, and the actual battery level could be very low.
We suggest performing a full charge and then recalibrating the battery.
Please follow the steps below:
- Please discharge all the power (charge AC & DC appliances with the power station till it is out of power and turns off automatically);
- Please charge it again, please do not load any device when charging it, and do not interrupt it while in charge.
- Once the power is 100% fully charged, turn off the machine, and leave it the whole day.
Please let us know if it does help.
I tried discharging the power but it seems the device only discharges when it’s on. It is able to stay on only for 15 seconds and turns off automatically. It discharges when on, but won’t stay on. As a consequence I cannot discharge it.
Try charging it first from a DC power source like solar or perhaps a 12 volt car power port (I am assuming that the power adapter it comes with is not charging it)? If the batteries are over-discharged then it won’t stay powered on, and cannot discharge, but the first priority is to see if they can take a charge at all.
The battery is fully charged. I plugged a heavy duty fan into it and for the 15 seconds the unit stays on, the fan ran great. I am unable to discharge it because it won’t stay on for more than 15 seconds. I can do this over and over - similar to Bill Murray in Groundhog Day.
I’m tempted to take it apart and find the positive and negative leads to the battery and discharge it from there, bypassing the BMS. Then I’ll see if it will charge through the BMS. Before that though, I"m hoping there is a way to bypass the BMS, or reset it if possible without dis-assemblying, and possible breaking the plastic.
I did attach a Bluetti solar panel to a charging port and got 22.7 volts and no amps.
What does the unit do if you plug in the adapter (nothing else, don’t turn it on or anything) to charge it? Does it power up and at least start charging?
Does it give the errors if you turn it on but don’t turn on any outputs (AC or DC)?
In the 15 seconds it powers on is it possible to clear the error history to make sure your only getting the current errors?
If I think of anything else I’ll be back. 
Thanks for trying. Nothing happens when either the AC or DC adapters are plugged in. The only way to turn it on is to push the power button. It beeps and the fault indicator lights 42 and 43 are highlighted.
I looked, but can’t find an explanation on how to clear the error history screen. It’s hard to explore in 15 second increments.
Also, Bluetti does not sell the BMS if that turns out to be bad. I’m starting to think these power stations (I have a working Goal Zero) are hit and miss when it comes to functionality…
Unfortunately the AC200P doesn’t support bluetooth or wireless, and hence doesn’t use an app.
Hi @Philos72, To clear the error code, please first click on “Alarm” on the screen, then select “Clear,” and click the “Yes” button.
However, based on your description, it seems that the machine may need repair. Please contact our after-sales service to arrange for a repair. The customer service email for the U.S. is service@bluettipower.com.
Additionally, please note that if you need my assistance, please @BLUETTI_CARE, otherwise, I might not see your message and be able to help you promptly.