AC300 Random Shutdown

Hi all,

I’m writing to see if anyone has any input on what I may not be considering and/or to get feedback from Bluetti on issue #1 below. The second issue is mostly just a complaint from being disappointed based on experience with other inverters.

I’m now on my second AC300 unit. The first unit was returned and replaced under warranty due to the dreaded 008 overvolt protection issue others have reported.

Since the replacement, I’ve been pretty happy with the unit. I no longer seem to have the WiFi issues that many others have reported. There is a strange issue where one battery is behind on firmware, yet I can’t upgrade it due to no upgraded firmware being available. This isn’t one of the issues, just an observation.

I primary use this unit as for boondocking in my RV. I have a 50 amp RV with a dog bone to 30 amp to plug the RV into the AC300. I understand electricity enough to know what I can run. I also understand compressors and their demand for energy to start. I also understand at 3000 watt, we are really limited to 25 amps @ 120 volts even though there is a 30 amp outlet on the unit (3600 watts @ 120)

Issue #1
NOTE: The batteries were between 75%-80% charge, and had both solar and shore power, when this happened (twice)

I have a Softstart on my RV which now gives me confidence that either AC will start on the AC300. Even with the Softstart, I can’t start both, which is completely fine with me. (15000 BTU and 13500 BTU).

One problem I’m having is the 15,000 BTU AC, with very few other items running, causes the AC300 to just stop working, but also doesn’t throw any errors in the logs that I over loaded the inverter. The AC runs for 1 to 1.5 hours never has to surge a second time since I set the thermostat set point way lower than the ambient temp.

I diligently monitored the unit and witnessed that I was always under 3000 watt with little possibility of a surge, to my knowledge. The first test I was admittedly around 2700 watts. The second test I rarely went over 1900 watts. I am extremely confident nothing caused the load to go above 3000 watts for any period of time. (I had the breaker off to anything else that could have surged including refrigerator)

A) The unit isn’t logging any error that I pushed the inverter too hard, which it always does when I know I made a mistake
B) The unit acts as if it were overloaded, shuts itself down for a minute or so then restarts. Everything works again for the same duration without any manual intervention.

Issue #2
This is more of a complaint than an issue, however, I’m very disappointed in the tolerance on the peak wattage. I have a Magnum 1212 on my house lead acid pack that handles peak/surges magnitudes better than this unit.

Had I realized the tolerance was so poor, I would have questioned even buying the unit. This is one of the only units with a 30amp RV outlet I know on the market , which made it extremely appealing.

In my current setup I can run ~30 minutes on my Magnum 1212 slightly over loaded. I can only run 2 minutes on this one. Without getting into all of the other peak tiers on each unit and the lack of tolerance on the AC300, it is just something to note.

I’m not sure if the wiring in the equipment simply can’t handle the peaks, or if the manufacturer is just just being overly cautious. I would have happily paid the extra few hundred to have wiring that would support higher peak tolerance given the application I’m using the unit for.

I suspect my random outages are due to yet another firmware problem with the AC300, but really am interested in what people think based on my description.

Hi @KeithB , sorry for inconvenience caused.
According to the two air conditioners you mentioned, they are 13,500 BTU and 15,000 BTU, which is already far more than the AC300 3000W with load. 12,000 BTU is roughly equal to 3516W, thank you.

Thank you for your feedback. This is not true, and as I mentioned, I monitored the load the entire time and never went above 1900 in one incident and 2700 in another as also noted.

I’ve also done several tests with different meters that show both ACs way under 3000 watts individually when running (Note, this isn’t starting, this is running watts). In fact, the 13,500 BTU ran all night long last night without the system shutting down.

To add to the evidence, I can run both ACs on an actual 30 amp pedestal which provides only 3600 watts @ 120 volts to the entire RV. Of course, I can’t run anything else but the ACs, but they do run.

The running watts below have been proven by the AC300 app and display, as well as several other meters, including the Softstart meter that was also being used to monitor during the outage.

The 13,500 BTU running watts with the compressor on: ~850watts
The 15,000 BTU running watts with the compressor on: ~1300 watts

I also indicated that the larger unit ran for 1-1.5 hours, which the AC300 trips after 2 minutes under a 3100-3750 watt load. The extremely minimal 500ms at 6000 watts explains not being able to start the second unit. However, it wouldn’t have been possible to run it for longer than two minutes with your calculated 3516W. It’s likely the surge to start the compressor might be 3516w, and that is in the realm of what the AC300 claims and does handle.

1 watt = 3.41 BTU/hr This would convert to something like 7326 watts ±
62 amps on single phase

I am reading .293 watts per BTU which is inline with Bluetti’s calculation of 3516W @ 12,000 BTU. My manufacturer indicates we have 27,000 BTU total, and my AC units are standard for an RV, so that is about right.

I’m assuming this is starting watts and not running watts. I have given the actual numbers several times. My numbers for actual running watts are correct and have been verified dozens of times over the last 2 years of owning my rig. Plus, I can run them both flawlessly on true 30 amp only providing 3600 watts.

Last night, I once again ran the what is apparently a12,000 not 13,500 for 12 hours straight on the AC300 (The battery was plugged in for this duration, but it also ran for 5 hours straight on our road trip to NY yesterday not plugged in). The 15,000 ran for over 4 hours straight yesterday as well. They did not run at the same time.

At this point, I’ve proven they will run on 25 amps. In fact, my breaker for the 15,000 is 25 amps and the 12,000 is 20 amps. These would not run if they required 62 amps. Most window AC units would never be able to run if they required 62 amps, as most standard outlets are 15-20.

Sticking to the actual problem:

  1. The unit isn’t indicating it is overloaded at any point, it just randomly stops and doesn’t log an error. This tells me that an overload isn’t happening, rather the unit may have some sort of other bug in the firmware.

Any time I DO actually overload it, it always reports an error and it is doing its job properly by shutting down. I have no complaints on this front except that their surge tolerance is way too low.

To illustrate my complaint about the lack of reasonable surge, here are the numbers for my Magnum MM1212, 1200 watt inverter, compared to the AC300 3000 watt inverter

5 sec surge power 2100W
30 sec surge power 1750W
5 min surge power 1450W
30 min surge power 1375W

2 min surge power 3100 - 3749
5 sec surge power 3750 - 4499
500 ms surge power 4500 - 6000

?? this math is rather surprising given that we have a 12k BTU A/C unit, and the most it ever draws is 1200W. And we’ve had the AC300 powering our 12k BTU air conditioner for the last 12 months, without issue.

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