Hi all.
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I have a few year old AC180 installed in my van. My van has a Victron inverter to supply AC power for charging the AC180 while engine is running via AC input port. It also has 100W solar panel to charge AC180 via DC input port. I also have a DC line from the van’s 12VDC port to the AC180 DC input port (only active while engine running). The solar panel and the 12VDC van port are connected in parallel to the AC180’s DC input port. I have the AC180 in Silent Charging Mode, which only draws up to 260 W when charging, so that it doesn’t exceed the 375 W output capacity of the Victron inverter. This has all worked great for a couple years now.
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I drove my van for several days ending on October 31, 2025. The state of charge was 100% at end of that trip. Since then it has been parked beside my house, with minimal solar charging since then (I’m in Washington State and we don’t get much sun during winter). I checked the AC180 3 months later on February 3, 2026 and found that the AC180 was off. Upon pressing the ON button, it turned on, showing 0%, 0 watts in, and with red “Low Voltage Alert” indicator, and then turned itself off. The display was on for only 4-5 seconds.
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Coincidentally, the van’s starter battery was also completely dead, but this appears to have been caused by the passenger door latch having failed and the door not being closed all the way and so the “door ajar” light was on, thus likely draining the starter battery over 3 months. I don’t think that this has anything to do with the issue with the AC180.
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I check the solar panel DC output and the Victron inverter AC output and all was working well.
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I brought the unit into my house for several days to allow it to adjust to room temperature. I then plugged it into standard US AC wall outlet. I verified that the cable was passing 120VAC to its Bluettie connector. Upon plugging it into the wall, the AC180 display turn on and again displayed 0%, 0 watts in, and the red “Low Voltage Alert” indicator and again turned itself off after 4-5 seconds.
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Regardless, I have left it plugged into the wall for 24 hours. When I try to turn it on, same thing happens: 4-5 seconds of displaying 0%, 0 watts in, and red “Low Voltage Alert” indication.
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I tried pressing DC and AC buttons together simultaneously for 10 seconds. Nothing happened.
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I tried pressing ON button for 30 seconds. This only resulted in 4-5 seconds of displaying 0%, 0 watts in, and red “Low Voltage Alert” indication.
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I plugged a 24VDC source into the AC180 DC input and, as usual, got 4-5 seconds of displaying 0%, 0 watts in, and red “Low Voltage Alert” indication, although there was a sound like an internal relay turning off at the end of the 4-5 second.
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During all of above, there were no AC or DC loads on the unit.
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The unit has been working very well up until now. No major charging or discharging issues and it has served well in my van running a small refrigerator, a small fan and other small loads.
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Seems that the battery level in the AC180 is too low to run its own charging circuit (which I consider to be poor design on the part of Bluetti who should have thought through such a scenario).
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Any suggestions?
If the battery is “deeply” discharged, the BMS may not negogiate charging even if you plug it into the wall. It’s known as overdischarging. On a freshly calibrated battery when the display hits 0% the system has 10% left because 10% is reserved for BMS. Problem is when you get to 0% you have no idea how much of that 10% is left. If the display turns on, there’s at least SOME % left, but there’s a point when BMS just shuts off to protect battery and will ignore charging. When it becomes overdischarged, there’s no really no option but to bypass the BMS, and to do so involves opening the case or sending back to Bluetti.
Thanks sealy1986!
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Yes, I agree with your assessment of it being deeply discharged, though I’m surprised that this would happen from 100% over only a 3 month period with no loads and with some cloudy day solar input. I have personal experience designing circuits for battery charging and low-power energy harvesting systems, and I’m a bit surprised that Bluetti didn’t design for this scenario. I can’t think why their BMS couldn’t be powered by external source when external source is available. That’s poor design in my opinion.
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I’ve contacted Bluetti Support to see what they think and how much it might cost to have them restore charge. But I dread the idea of shipping this thing.
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Do you know of any on-line guides on the “opening the case” recharge option?
Yes on the surface is certainly does sound unusual, but keep in mind we are talking the winter time in the PNW. The AC180 has a self consumption of about 6 watts which is at minimum 144Wh/day. A 100 watt solar panel if its flat mounted would produce only 25% of its power so maybe 25 watts for say 6 hours a day in full sun. On a cloudy day, maybe 10-15 watts. You can very possibly slowly lose a net charge every day. The other side of the coin to consider is how cold was the van? The Bluetti AC180 will refuse to charge below 32F to protect the cells, but can and will continue to discharge up to -4F. The cold weather wrecks havoc on the cells and could lead to bad cells as well. Long term storage dictates the unit should have been kept in a humid-free, climate controlled environment with a SOC around 50-60% for cell balancing and health. Very likely you killed it by storing it in the cold van all winter is my guess.
@BradMitchellPhotography @sealy1986 I agree with the above.
Normal operation does not cause self discharge to that extent. I have 2 “ganged” AC180s at my inside generator transfer switch. I store their SOC at 70% as they do not get used unless the grid goes down. I check them every month or so with a quick turn on, then off again. After 6 months the SOC dropped about 2%, likely due to my checking inbetween.
At the 6 month point, I discharge them to around 5%SOC (just in case), then fully recharge to 100%. After which, I then drop the SOC back to 70%. However, here in Australia, where I live, the inside temperature, with aircon use only varies between 12C and 25C (54 to 77F).
My take from all of this is - “regardless of ambient temp, check your power stations once a month, even if not used.” That way you have more chance of picking up on abnormalities. 
Powered off, yes. The voltage will drop maybe 2% per MONTH at room temp. Even less in colder weather. But if the unit was on the entire time (say DC port was left on) or ECO mode was off and the unit was powered ON but AC/DC ports were off it would consume 6 or so watts from self consumption. 144Wh or 12.5% per day if you assume no net positive charge.
Yea, we have had a pretty tame winter this year so far, much warmer than the past two winters, during which the AC180 didn’t have any problems. But I definitely have negative net solar charge / self-discharge in winter.
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Also, my unit runs on an alternate version of firmware provided by Bluetti to solve this other problem from about 2 1/2 years ago. This alternate version of firmware does result in higher than normal self-discharge. I consider this older problem to be another Bluetti design flaw in that the solar input didn’t initiate charging on its own after 1 night. You had to manually unplug and re-plug the solar panel back into the unit each morning, which I thought was ridiculous, so they provided the updated firmware that has the trade-off of even higher self-discharge rate.
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Here were the self-discharge rates I found at the time with the new firmware:
AC180 in standby: 3W continuous self-discharge rate.
AC180 DC output circuit on: 3W continuous self-discharge rate.
AC180 AC output circuit on: 12W continuous self-discharge rate.
AC180 off: 0 self-discharge rate (i.e. not measurable over 24 hours).
So my error this winter was in that I probably left the unit in “standby” versus “off” for 3 months.
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“Standby” means that the AC and DC outputs are turned off, but that the unit itself was not turned off by holding the “ON” button for several seconds (note that the unit does not charge when off).
I probably need to follow a procedure like Mandp describes during the winters.
Anyway, does anyone have any instructions for the “opening the case” recharge option?
Brad, I’ve seen a couple of Youtube vids on a “tear down” process. I seem to remember there may also be something re wake up. I believe you need to “fool” the BMS by applying a small voltage to the cells. Maybe @BLUETTI_CARE may help.
I just posted a new thread about a simular problem.
have you checked the individual banks to see if they are balanced?
Hi @BradMitchellPhotography, according to your description, we believe the issue with your A180 is due to over-discharge caused by gradual power loss during long-term storage.
If slow charging via the car charger cannot fix the problem, we will have to arrange warranty service. It seems you have already contacted our support team; could you please provide your service ticket number so we can follow up on the process?
We would like to thank @sealy1986 and @Mandp for their professional and detailed explanations. Improper handling may cause additional issues, so we strongly advise against disassembling or repairing the unit by yourself.