I have two stations, AC180P and AC70P, both in the same conditions. But if I plug the same equipment into one station and then into the other, the power usage of the two stations will be significantly different.
For example:
3 monitors and a laptop are connected to the AC70P and the AC70P claims that the load on the station is ~200 watts. In the same minute, I unplug the same items from the AC70P and connect them to the AC180P in the same way, and the AC180P claims that the load on the station is up to 120 watts.
This is normal and it has nothing to do with efficiency.
At low current and for certain loads, the displayed wattage is approximate and that depends on the kind of load applied to it, be it resistive, capacitive or inductive. Some kind of loads generate a so called apparent power which increase the error on the power calculations, especially at low currents.
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If you would like to compare the displayed wattage on the two units you should use a resistive load, for example a ceramic heater.
Or, if you would like to precisely measure the wattage of mixed loads you could use an external meter which also take into account some error correction.
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But, on a general note, always consider that power meters precision always rely on a curve, which gets better at greater loads, and the same apply to conversion efficiency.
Am I right in assuming that no matter what load is written there, everything is working properly and both stations are actually taking the same load, just one of them is counting incorrectly?
Yes, everything is working properly and both stations are taking the same load.
About the difference I will not say it’s incorrect, just consider that the 2 units have a very different inverting capacity (1800 against 1000 watt) and different characteristics so it’s normal they will behave differently with mixed resistive, capacitive and inductive loads from power supplies of monitors and laptops. If, for instance, you will do the same test with an AC300 or a storage system from another brand you will have more slightly different results.
But again, if that test will be done with a resistive load and more power, such as a 500 watt-nominal load, you will get a result from both units which will be almost equal.
Another aspect, my 700W microwave pulls around 1200W from the grid, the same M/W uses nearer 1400W from the AC180.
Why, the grid is at 240VAC, the Bluetti is 230VAC and then there’s the efficiency power factor to consider.
xxxxxxxxxxxxxxxxxxx These are not displayed watts, but from the same separate power meter plugged into grid and Bluetti.
@design
This is due to a different display strategy.
When the load power is less than 50W AC70 shows active power; when it is greater than 50W, it shows apparent power.
When the load power is less than 200W, AC180 shows the active power; when it is greater than 200W, it shows the apparent power.
