AC180 grid wattage is significantly different from wattmeter

My AC180 is plugged into my wattmeter and the latter says my AC180 is drawing around 373 watts which is significantly lower than what is shown on my Bluetti screen (600+ watts).

I tried plugging my other wattmeter and the results are similar. Anybody know why?

Hi @Jayar

Does the AC180 display do show the same value, that is in the App?


Yes. AC180 screen and Bluetti app show the same values.

hmm okay, because i remembered a casse with a EB3A, where just the values of the Bluetti App where wrong.

@BLUETTI_CARE Do you have any idea, what cause this issue?

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On your wattmeter, do you also have access to the apparent power, in addition to the active power ?
Is it a fridge or a pump… which is connected to your AC180 used in passthrough?

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@Jayar Can you please test to load a higher powered device with AC180?

So I tried both loading both low and high wattage. For 7w, my wattmeter plays between 6 & 7, the AC180 is between 9 and 10. Started my 1kw coffee maker and the wattmeter is between 980 & 1kw while the AC180 shows 1.4kw plus. Values are way off.

One fridge and one freezer were connected separately. My wattmeter doesn’t show apparent power, unfortunately.

I will connect a resistive load, such as a kettle, to see if the power (active therefore) measured by your ac180 is the same as that of your wattmeter (remove the fridges of course!).

Are both your watt meters the same type and brand? I have a few "Kilawatt
type meters that display incorrect information but not to that degree.

Thanks, @Snips1. I’ll try this and will give you an update.

Yep. Wattmeters are the same brand, same model. Differences in wattage readings are minimal.

Plugged my 800w kettle. Showing 755 to 756w on both wattmeters while the AC180 plays between 869 and 880w. I guess I’ll have to live with it for now. It’s not really an inconvenience. I was just wondering why my unit is showing a different value and if there was an explanation. Everything else works normally–especially its UPS feature which I truly enjoy. Thank you so much, guys! I love this helpful community!

Bluetti should be able to answer your question.

My hypothesis is that when the AC180 is fully charged and used in passthrough, it would measure more apparent power and not active power (your wattmeters measures active power). So when you plug in your fridges and freezers, you know that you’re going to have quite a lot of reactive power, so the apparent power will be much higher than the real power. So for the measurement with your fridges we have a big difference 373W/613W = 61% (=cosPhi?). But when it comes to your kettle, it is mainly active power and there the measurements are closer: 756/869 = 87%…
Unless it’s your AC180 that’s got a problem… I hope Bluetti can answer your question.

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My AC180 values -
30A lithium charger draws 530W from grid (power meter), the AC180 screen shows 570W.
700W microwave draws 1200W from grid (power meter), the AC180 screen shows 1390W.
My conclusions (noted in other thread);

  1. The efficiency drop of inverting from battery, the electronics of the Bluetti BMS and other parasitic loads cause the difference between what power a device uses and the power output of the Bluetti to provide that power.
  2. The higher the load, the 2 examples above, the larger the difference between the 2 measurements. (The lower draw is around a 7.5% increase, the larger nearer 15%) Both are within specification.
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Mabdp, Your measurements with your wattmeter are closer than those of Jayar…
Jayar’s case leaves me perplexed :thinking:

Yes they are. I’m at a loss to explain his readings.
As an aside, I also have a silicone folding travel kettle, it has a rating of 900-1100 watts (240VAC), go figure a 200W range lol.
I’ve run it from my AC70 with 0.5lt of water (approx 1pint) with the cold water temp at 8 deg C (46F).
The AC70 showed a constant load of 1035W, (within specs) it boiled the water without tripping the Bluetti and power lifting was off. Unfortunately, I did not have my external power meter at the time to measure actual kettle load.
Given my result, it only adds to his issue…

Edit. All of my results are with power banks off grid connect, not pass thru, UPS.

@Snips1 @Mandp
Thank you for your inputs. I am removing my wattmeter altogether and will just rely on my AC180’s somewhat questionable readings :laughing:. At least I am assured that I won’t be exceeding the load.

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