AC200P limited charging

Continuing the discussion from AC200P not charging fully:

Hello all,
I have a similar problem. My AC200P was working fine as an RV 110VAC power source until I plugged in a USB-C device, left it charging overnight. The AC200P will only charge to 9% before immediately reading 100% charge. When I load it with a 110v lamp, it will run for about 40 min before shutting off (144W load) and showing 0%. Applying AC charger to the unit, it charges from 0% to 100% in 24 minutes…obviously the power station is not working properly. I cannot get a response from the two numbers listed as customer service or the email address…can anyone help?

Other than fully draining to 0 and then recharging to 100% a few times (which it sounds like you have already done) I can’t offer any other suggestions. That is a strange issue. What were the circumstances after the next day from being connected to the USB–C device? Battery at 0%, screen shut off etc? Are your temps above 32 degrees or room temperature range?

The Bluetti community seems to have several persons with similar problems but the maximum state of charge seems to vary. The temps were normal room temperatures. The LCD screen remained active and sensitive to touch, no problem there. I tried a test, started with 100% displayed charge, plugged an incandescent lamp into the AC system, it showed a 143/144 watt loading and timed how long the light was on. It shut off after exactly 40 minutes, showing 0% in the LCD display, equating to a 144W x 0.6666 hours = 96 watt-hours of power. That’s about a 5% charge capacity.
I tried charging with AC (multiple cycles), once with SP120 solar panels (exceeding minimum voltage) and a DC car charger. Still cannot get a charge above 18%. Sometimes the max charge gets to 9% or 12% before showing 100% immediately. The two numbers for Bluetti go to voicemail (I’ve left messages). No responses. I just emailed service@bluetti again. There’s a YouTube video of a guy disassembling the device, accessing the direct terminals of the battery and using the AC charger to get the battery charged above 46 volts…and then he says the AC200P works ‘normally’. i don’t want to open this up. Any chance you have access to Bluetti service? the unit is only 12 months old.
Thanks,
John

oh sorry, forgot to answer one of your questions, the LCD display showed 0% the next day before starting the charging process, apparently ‘normal’ charging…then it only goes to 9% or 12% or 16% or 18% and then directly to 100%. The different numbers are the different tries at cycling the system.

Sorry, but I have the same contact info available that you have been working with. They are going to want your sales order number and a video showing the specific issue. I don’t see anything else that can explain the issue other than Bluetti Service handling the issue. The issue on the video you mentioned where the user opened the case directly to charge involved no charging at all occurring. In your case you are getting charging to occur and is sounds like the system is inaccurately thinking the state of charge is higher than actual. @Markyue

Scott,
Max at Bluetti contacted me via email this morning and asked that I cycle a charge with AC and then a load. I did that and sent him the following response. He did ask for the serial number on the barcode on the bottom and an address/phone so I am hopeful he will provide a replacement/repair or refund.
John

“Max,
Thank you for your response. I have tried the sequence you requested below several times. This morning, I applied the AC charger to the AC200P (without a load) and the LCD display reported 8% initially upon activating the power button…and then the display went to 100% after about 2 minutes of ~375W charging from the AC charger. I then disconnected the charger and placed an incandescent lamp load on the AC200P. The load was listed as 144watts.
I left the load on from 6:37am with a display showing 100% charge. The lamp remained on until 7:27am, when the AC200P showed 81% and then automatically turned off the AC power and the display then showed 0% charge. The overall power drawn was 50 minutes of 144W (which drooped to 122W before shutting off) or 5/6 hours x about 140 watts for a total of 116 watt-hours, well below the advertised 2000 watt-hours capacity. Please replace or refund. Note: I do not want a replacement if there is no fix for this problem in the design. Thank you.”

Good to hear you had contact with Bluetti. In my experience it is not a design issue but seems more like a failed battery detection system or the battery itself. I have heard of maybe one or two others of the same issue out of the many thousands of units out there. If it were me, I would accept the replacement and if you had any further issues, pursue the refund or possibly upgrade to the AC200Max (different design and components) by possibly paying the difference.

I have a pair of the original AC200’s and I keep them charged at 100% and when draining, often drain to 0% and I have not had any issues over the year and a half that I have owned them other than one temperature screen showing lower than actual.

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Thanks for the insight on the battery, good point about possibly upgrading to the AC200Max with a little extra funds. I will see how Max responds.
John

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Scott,
Bluetti resolved my issue by providing a refund for 90% of the purchase price (it was a year old). They provided an RMA to send it back. They believe the issue was the BMS and possibly a bad cell.
John