What is the PV charging trigger voltage?

Product Discussion BLUETTI AC Series
1

Hi,
Anyone knows what is the PV charging voltage trigger point?
I have a bluetti 200Max that I use for camping.
I am trying to find a solution to charge in my car. The cigarette lighter can only output 80w, and drops to 60w quite often.
I tried with a xwst 12v to 48v DC converter and found that it was charging at over 700w. But the DC converter I bought was only rated at 10A. And very soon, it blew off. Not only that, I also discharged my cranking battery. I almost failed to start my car the next time.

I think problem probably was that my alternator couldn’t keep up with the charging rate of 700w(considering energy loss, the output from my car could be ~800w), and it discharged my cranking battery since I’ve already got a second batter which draws ~30A from the alternator and the alternator was rated for 100A.

So, 12v-to-48v converter would not work for me. Then I tried with a 12v-to-24v converter. And now it can only charge with 180w-195w. The charging voltage is only 22v.

Then I realised that in PV charging mode, the charging current is 15A, while in car charging mode, the max current is only 10A.
There must be a certain voltage that will trigger PV charging mode. I wonder what that voltage is.
From the settings, you can choose input source, but I found that doesn’t help. Switching input to PV mode, I still get the same charging rate of 180w.

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2

You don’t have to wonder what the PV charging voltage range is. The specification of 10 to 145 VDC is printed on the unit and also available in the user manual that came with your unit or available on line. You will need to be above 30 VDC for the AC200Max to not operate in car charge mode though.

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3

Thanks.
30V, that’s what I want to know. I’ve ordered a 12-to-36v DC converter.
My understanding is if it’s lower than 30v, it can only charge at a maximum of 8A.
Just don’t understand why that’s the case.

4

It is that way so vehicle charging sockets and charging plugs do not overheat and melt

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5

That makes sense. But for bigger power stations like AC200, it’s so inefficient. It would be nice if they have a fast charging mode for 12v source.

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6

They do, just put in PV mode and connect to a 12 volt to 36 or 48 volt strp up converter.

7

@laocius Have you ever heard of the D050S Charging Enhancer that Bluetti makes?? Check it out here…

https://www.bluettipower.com/products/dc-charging-enhanncer-d050s


It allows an input of 12-60v and outputs 16-58.8VDC (up to 500w) thru the dc7909 barrel plug. Potentially increasing your AC200Max to have a PV input of up to 1400w.

8

Yes, but it doesn’t help in my case. I’m not using solar. I just want to put it in my car and use it for camping.

9

@laocius the PV/DC input doesnt necessarily mean it needs to come from solar panels. Could come from a direct feed from your cars battery.

I think you should also check out this post from @Scott-Benson and how he uses a step-up converter to increase charging rates for his unit while on the road. Heres the link…

10

I know. I mean the enhancer won’t help for car charging as it can only charge at max 10A. You still need to boost voltage first.

11

That would require a very high amperage DC charging source which most customers do not have access to or the knowledge of how to obtain

12

Something is weird here.

I have tested 18V Power Tool Batteries as an emergency DC-charge-option for the AC200Max. I just ran into an issue, I can’t figure out:

I have a Box where the 18V Battery goes trough a Low-Voltage protector board, and then 1:1 out for whatever I want to connect (depending on Battery charge level, Voltage will be between 16-20V). If I connect the AC200Max (on PV-Mode), it will charge up to around 200W, which makes sense (20V*15A). This however I feel is too much current draw for the 6Amp PowerTool-Battery.

So I decided to build another box, very similar, which has 4 of these Batteries in Series (remains at the 16-18V-Level, but has a combined 24Ah). If I connect to this box, the AC200Max will switch from PV-Mode to Car-Mode, and then stop charging all together, because the Voltage is considered too low for a 24V-System, and too high for a 12V system.

I just don’t get why on one of my boxes (with the same Batteries) will remain in PV-Mode and pull the full 15A, and on the other box (with up to 4 times the Batteries) it falls back to car mode and stops charging alltogether.

With the previous in mind: I also would like to know the charging logic behind it, currently it does not make sense to me and I am lost.

Have posted a question in this regards here: AC200MAC - Customize DV (Car-Charging) Voltages

The manual states, that the PV-Voltage can be between 14–145VDC, so this is different from the statement that laocius made above (he mentioned that the Box requires 30V to charge with 15Amp [PV-Mode]…

13

Interesting!
I’m guessing there are voltage ranges for car charge mode and PV charge mode.
If they say 11-14v and 23-29v are car charging voltages, then it’s possible that 15-22v is considered PV charge mode. Would need to run some tests to find out. But regarding power draw, I don’t think 15A is high for power tool batteries. 4Ah is the capacity of the battery, which means you run at 4AMP, it can last one hour. Usually, power too batteries can discharge at very high current. 20A-50A is normal.

14

I agree. The power tool batteries can deliver very high current draw.
Limiting the current draw (and the internal heat) will however increase life, and since I have a few of these, I can do just that, and can deliver more Wh into the AC200Max with a pack of 4 in parallel, so I don’t have to change them every few minutes if I need to give the AC200Max some backup juice :-)

If I just could figure out what makes the Box fall back to car charge mode, not accepting my ~20V pack at all (but showing 20V connected in the Menu, without current draw)…

…There could be light at the end of the tunnel :-) Bluetti Support might modify/push a firmware, as can be seen in the before-mentioned thread.