AC200p massive amperage drop off when charging?

Product Discussion BLUETTI AC Series
1

So I had posted about a month ago since I was only getting .1-.2 amps while charging, with 35-38v on 2 100w panels. Anyways some suggested I might just be teetering on the edge of the 35v minimum charging on the ac200p. So I bought a 3rd panel. Funny thing, it worked, but then the wattage was only 40-60w on a good day. Contacted the manufacturer of my panels and we determined I had a bad one. So I took it out of service and now I get the same 40-60w on 2 panels.

Now this is where I’m getting confused. My amperage at the cable before I connect it to my ac200p is around 2.9 amps. When I connect the cable, it drops down to around 1.1-1.3 amps. Does anyone have any idea why? Do I have a defective unit or something?

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PXL_20230905_1926019753072×4080 2.05 MB

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PXL_20230905_1922335161536×2040 1.61 MB

2

Looking at the last picture, it looks like you’re trying to measure amps directly from the solar cable, which isn’t going to work, at least for most meters. Also, since there’s no load, there won’t be any amps. A lot of meters need to be zero’d properly, especially for amps. For a meter to properly read amps, it needs to be inline between the source and load.

3

So without destroying anything, how could I do that?

4

@rgb Please check if you have turned on PV mode.
image

5

Yes pv charging mode is on.

6

You can find a number of inline watt/amp meters for under $20, though most of them require you to add connectors yourself, either soldier or crimp. You could add XT90 connectors to it, or MC4, depending on your needs. If the AC200P is similar to the AC200MAX, then the XT90 would be a better choice. For some reason when I googled for meters with connectors already attached, the price really jumped up, but I only did a quick google. Search for “inline watt meter XT90”.
Note that with the AC200P, an inline watt meter is going to show about the same thing as what you see on it’s screen for watts, volts and amps.
And just a reminder, if the source (panels) are not connected to a load (the ac200p), you are not going to have amps/watts, only volts (VOC).

7

@rgb I suggest you change the solar charging cable to test.

8

Clamp-on Ammeters work great and are not limited to 10 amps as are most voltmters. Reads amps instantly as you move from one panel to another. Mine also doubles as a voltmter. I think I paid maybe $25 a few years ago.
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I have some panels plugged directly into 3 B300s batteries. Since the wattage doesn’t show up in the App, I can instantly see how many amps are feeding into the batteries. Then unplug it and get a voltage reading to calculate wattage. P=IxE