2x SP120's in series will not charge AC200

I am pretty sure I used to charge my AC200 w/ 2 SP120’s because 2 have Vmp with max sun 39.6V and the AC200 needs 35V. But today in full beautiful (but hot) sun I am getting 31.x V. The AC200 is acting like it’s charging but it’s only increased 1%. Thoughts, or anything I could test? And I’m surprised if it wants 35 and it’s not getting it that it is doing anything at al. Thanks!

Hi @Lee , The VOC of two SP120 solar panels connected in series is 47V, which can be charged if it matches the VOC range of AC200.
There are many factors that affect the solar input. Is your solar panel covered? Is there dirt on the surface? What is the length of your connection cable please?

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It would be helpful if you stated how many watts of incoming charging you are receiving and a picture of your panels showing the conditions.

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@Scott-Benson @BLUETTI I have taken some pics and a video. Today I am getting more voltage than I did a couple days ago in same conditions (no shade, full sun, a very hot Houston TX at 2pm). I did clean the panels today (they weren’t that dirty but a little dust). On the AC200 I am fluctuating every half second or so between 33 and 38V, but on a multimeter connected to the outputs on the panels, and the yellow XT60, and the aviation plug that plugs into the AC200, I am getting a steady 43.1V or so. I tried measuring current with my multimeter but it doesn’t seem right (like it climbs and keeps climbing). Connection cable length is just the panels plus what came with the AC200. So not long.

What PV setting do you have chosen in the settings screen? “PV” should be the appropriate setting for charging with the setup you are describing.

Yes it is set on PV. I’ve been trying to post pics of the stuff you guys are asking me for but I just realized I cannot post more than one at a time. Wire length is just what came with the Bluetti and the panels, no extensions. Here is a pic of multimeter attached to solar panels.

Here is a pic of my setup.

Here is a pic of Bluetti showing 35v at the same time the multimeter is showing 43 above.

The voltage drops one under load. The screen pic you sent shows 136 watts of charging input. Not sure why you are saying you are not receiving a charge?

Hey @Scott-Benson thank you for responding. What do you mean voltage drops one under load? Also see this other pic I just took. I am wondering how, if the AC200 wants 35V minimum, how is it charging if I’m at 31V?

To confirm, I am on PV not car charging.

The spec for the bluetti is minimum 35 volts but will in fact charge at slightly over 30 volts. Solar panels will produce a higher voltage when not connected to any load. The same voltage will drop when connected to a load (ie connecting to your bluetti for charging). For example you may see 35 volts when first connected and that can drop to around 28 volts when charging begins but Will not continue since it is below the absolute minimum bolts required to charge. Solar panels give the absolute voltage (VOC) and the voltage under load (VMP) as separate specifications as an aid to choosing the correct panel for the intended application.