AC200Max wrong power level

Hello Folks, I have an AC200max linked to a B300, a single T500 charger and a second T500 just ordered to increase charge speed. The units are charged via ac wall power. The issue I have is the AC200max power level dropping as it should down to approx 30 -20 ish %. And then for some reason, and sometimes without me realizing, the display shoots up to 70-90% reading on the screen, as the amount of power available. With this misleading display information, I sometimes then loose a fridge full of food as the battery was almost drained, and does die taking the cooler with it. Is it common for the AC200max display to jump to a high level of power available when there is in reality only a small amount of power left? Thanks. Long Distance Traveller

Hi @LongDistanceTraveller, Can you tell us the SN number of your AC200MAX, and the current BMS version, and your country? We will try to resolve this problem by upgrading the firmware. After upgrading, we suggest you calibrate the AC200MAX for better performance.

Sn - 2238001803283. DSP 4005.07 Arm- 4030.15. BMS- 1017.02. Hmi - 6023.11 Canada

I had the Ac200 max +B300 draw down at typical rate this past week …. and then display went from 36% to 0% percent in about an hour today and shut the cooler down. We will now run the Van engine in parking lot waiting for a health appointment for the next 6 hours to keep the cooler running till we can get to a plug in later this eve to charge. I am hoping we have enough gas to do all this and not loose our load of groceries that we just bought today…uuggg….

Is Bluetti looking into something regarding the firmware?

Your BMS needs to be updated and then as Bluetti mentioned you need to do the calibration. This should help.

Bluetti care said “We need to…” So I assumed instructions were incoming. So if not…. how is this update accomplished?

Two days ago I had a similar problem with a sudden loss of power. At 10 in the evening I had 72% left and at 5 the next morning I looked in the app and saw there was 27% left. I thought it was already a big drop and while I was calculating if it could be true, I saw the power drop in just a couple of seconds to 0%. I have a smart connector between the Bluetti and the fridge and it states that the power stopped at 4.25. Maybe there is something wrong with communication to the app or the Bluetti has send old data to the app when I started the app.