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Using more solar panels during winter on Bluetti AC300

thomas738

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Mar 8, 2022
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Just ordered a Bluetti AC300 with one B300 and planning for the next winter when energy in Europe may be limited due to the Ukrainian crisis. Main idea: More solar panels!

The AC300 can handle 2 x 1200 W, each up to 150 V and 12 A. I learned that the voltage may not be exceeded, but what about the electrical current? Will the AC300 cut everything above 12 A automatically?

In my concrete situation, I have access to 12 panels each with 400 Wp, I_SC and I_MPP ca. 12 A, U_OC = 41 V, and U_MPP = 34 V. Total of 4800 Wp.

Could I use 6 panels for each AC300 string yielding 2400 Wp if I take care that voltage is less than 150 V, but electric current may be up to 24 A? (I guess in winter this value will never be reached...)

If not, is there any other option to use more panels?

Thanks a lot and greetings from Europe, Thomas
 
The AC300 can handle 2 x 1200 W, each up to 150 V and 12 A. I learned that the voltage may not be exceeded, but what about the electrical current? Will the AC300 cut everything above 12 A automatically?

Yes, but some systems have a limit.

In my concrete situation, I have access to 12 panels each with 400 Wp, I_SC and I_MPP ca. 12 A, U_OC = 41 V, and U_MPP = 34 V. Total of 4800 Wp.

Could I use 6 panels for each AC300 string yielding 2400 Wp if I take care that voltage is less than 150 V, but electric current may be up to 24 A? (I guess in winter this value will never be reached...)

make sure to give yourself some headroom for cold temperature effects.

Your scenario would likely work even better if you had your 1/2 of your array facing SE and the other half facing SW - Less peak current and wider range of performance.
 
Thanks @sunshine_eggo! This is awesome!

I checked on the PV Parallel Enable setting which is not well documented in the AC300 manual. But in the video tutorial (
), it is described as follows:

"If you're drawing too much current from your solar panels, if you have more current than can be supported, some of that solar power will be wasted. So if you're drawing more solar power than can be supported by one circuit, you need to be sure to set this to on, then the AC300 will divide the power between two circuits and allow you to get the maximum amount of solar power that you're receiving."

In summary I will do the following:
  • Put 6 panels (2400 Wp) facing south-east on DC input source 1 and
  • put the other 6 panels facing south-west on DC input source 2.
  • Making sure voltage is less than 150 V including headroom on each DC input source.
Correct?
Best, Thomas
 
I just saw that @Will Prowse commented on the PV Parallel Enable setting in his video:
"These are separate inputs but you can actually parallel them if you change the settings on the screen. And, personally, I think that's somewhat useless. I really wanted to know why they would parallel two separate arrays. Personally, I would have them separate and I would use both separate MPPTs."

This brings up a question: Are both strings still optimized by the separate MPPTs when the PV Parallel Enable setting is turned on?

To my understanding, Will thinks they are not optimized separately. The video tutorial is not commenting on the MPPTs and it sounds just that a smaller current on one string can be compensated with a larger current on the other string in order to get as much current in total as possible. I wish, the Bluetti manual would be more informative...
 
Thanks @sunshine_eggo! This is awesome!

I checked on the PV Parallel Enable setting which is not well documented in the AC300 manual. But in the video tutorial (
), it is described as follows:

"If you're drawing too much current from your solar panels, if you have more current than can be supported, some of that solar power will be wasted. So if you're drawing more solar power than can be supported by one circuit, you need to be sure to set this to on, then the AC300 will divide the power between two circuits and allow you to get the maximum amount of solar power that you're receiving."

In summary I will do the following:
  • Put 6 panels (2400 Wp) facing south-east on DC input source 1 and
  • put the other 6 panels facing south-west on DC input source 2.
  • Making sure voltage is less than 150 V including headroom on each DC input source.
Correct?
Best, Thomas
Hi, I liked your idea and I would love if it works. Can you update us if you have done tests with 12 panels connected to the AC300? Thx so much!
 
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I also have an AC300 and am looking into maximizing its solar input for my RV. I've outlayed my options on a graphic of the roof of my RV and would be really grateful for any advice. Interested in maxing out an AC300 if possible. The green panels are 200W and look like they may afford me an extra 100W if I'm not missing something. The blue are the 100W panels.

With all 100W panels, you can see I can fit 23 but I can't go over 5S. If I went 6S on either chain, I would have to unplug it below 60 deg f.

So I would be able to plug one 5S2P chain into one MPPT on the AC300 and another to the other MPPT (each coming in at 121.5V) and likely around 1600watts best condition (they will be mounted flat of course)

That's not very close to the 2400W max so That leaves me with what to do with the other 3 panels. I suppose I can plug those directly into the batterys as they have their own MPPT or maybe I can use the charging enhance in some way? Also, as you can see, theres a way to put two 200W panels in place of the 3 100W instead. So maybe those would be well suited to plug directly into the battery.

I would like to be able to run my AC and as such, worry about finding out how to really maximize this array with the roof area I have.

Incidentally; I also don't mind adding, and actually plan to buy, a ground portable panel. Mostly for use when I take my truck to more remote locations than the RV can reach.

Also, just making sure, as I understand it; I dont have to worry about the 12 amp "limit" at all?

Any help would be GREATLY appreciated as I feel like I might be missing something. Maybe there's some kind of 3P layout that I'm missing.

Here are the links to the panels


 
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It took some time to receive the solar panels and to set up everything. I have now the following setting using nine 400 W solar panels:

MPPT1: 2 x 1200 W in parallel, i.e. 2 x 3 solar panels
MPPT2: 1 x 1200 W, i.e. 1 x 3 solar panels

It works great and the AC300 is not complaining about too high currents, even in perfect sunshine. For MPPT1, the AC300 reports up to ca. 1220 W.

If I turn on the PV Parallel Enabled setting, the system shows a PV Parallel error and the current drops to 0. I guess @Will Prowse is right and this setting is really useless.

In the winter season I will add the remaining 3 panels to MPPT2 in parallel to the existing ones.

Cheers, Thomas
 
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