AC200 Max not taking full available solar

Hello, I have an AC200 Max and have noticed an issue regarding it’s solar input. I have had the unit for about 6 months and use it regularly to power a refrigerator. I have been powering it with five 190 watt panels and it has been doing fine. I recently changed the panel layout to two connected parallel sets of 4 panels connected in series (2p4s). Each string will put out over 600 watts (peak) individually as I have verified and tested this. I have noticed that during the day as the sun gets higher and the solar should be increasing, the 900 watt solar input of the AC200 max stops at about 750 watts. So I’ll turn off one of the two parallel strings and check wattage of that string. Each string is putting out around 500-600 watts, so the combined total for the two strings in parallel should have no problem reaching the 900 watt max solar input, but it does. It seems to be capping out at 750 watts. So I flip the PV disconnect off and on for one of the strings and then the AC200 starts receiving the proper 900 watts into the solar and will keep at the proper amount the rest of the day.

I’ve had this happen the last three days since I’ve installed the second string of panels in parallel. Why would the system be receiving 750 watts (peak hours of the day) and when I flip the PV disconnect off and on it automatically jumps to 920 watts?

Hi @kent

i know this problem from another powerstation of another brand that i own.

It starts with full power and after some time it get stuck at a fixed value. After reconnect the powerstation and the PV its going again the highest possible value.

I never really get why exactly it does work like this. Try multiple different panels, all the same. But this is only one panel.

I had a similar Issue you described with EB240 where Solarcharging stuck on 38W. The problem here was that i use different panels that are wired in series at this time.

Do you using all the same panels in your setup?

Hi Erik,
Yes, all panels are the same. Two strings of four HQST 190 watt panels wired in series

@kent May I know the specification of the solar panel? Did you try to connect the solar panel in series?

The mentioned Panel “HQST 190 Watt” have the following specs:

  • Max Power at STC ( P max ): 190W
  • Open-Circuit Voltage ( Voc ): 24.3V
  • Optimum Operating Voltage ( Vmp ): 20.3V
  • Optimum Operating Current ( Imp ): 9.36A
  • Short-Circuit Current ( Isc ): 10.15A

In his Post he say that he have 4 panels overall. He run 2 pairs of series which are connected parallel together.

Series: 2 x 24,3V + 2 x 24,3V
Parallel: 48,6V + 10,15A + 10,15A

Input: 48,6V 20,30A

Do i get this right @kent @BLUETTI_CARE ?
Yes, the panel specs are correct but the panel arrangement is incorrect
4 panels in series and another set of 4 panels in series, connected together “paralleled”

I’ve do this arrangement before with another Bluetti AC200Max (the first one I owned was destroyed by water) and it always worked fine

If I connect all 8 panels in series it would be over the 145 volt limit

@kent Could you please provide me with the SN and the firmware version of your AC200MAX? I can check if there is firmware suitable for your case.

SN is 2232002619798

DSP 4005.07
ARM 4030.15
BMS 1017.02
HMI 6023.11
BMS1 1014.13
BMS2 1014.13

Ok, you have 8 panels connected in 4S2P combination :tipping_hand_man:, this means that the combination connection results in 2 X the Amps of one panel :tipping_hand_man:; Hence, this exceeds the Max PV input of 15 Amps for the AC200Maxm​:tipping_hand_man:. Therefore, you cannot attatin the max power from the panels :tipping_hand_man::tipping_hand_man:.

The way it works:

The way it works for combinations: xSyP = x panels connected in a series string, then y series strings connected in parallel, … x X y = number of panels ; that gives x times Volts of one panel with y times Amp of one panel to the power station :tipping_hand_man:

@kent Please try to update the DSP version to 4005.08 to test.

Update fixed the problem. System is now taking full available solar charge.


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Just for your information, if the amount of current (amps) that a solar array can provide is greater than what the system can use it is not a problem. The MPPT controller will regulate the current coming in to system. The primary thing to be concerned about when putting a solar array together is that the Voc is not greater than what the system will allow, as too high a voltage will damage the charging circuits. Having more current available in the solar array is referred to as “over paneling”. The advantage of doing this is that the solar array will provide the maximum solar input the system can take at an earlier time in the day, and during less than ideal weather conditions. This will help generate more power more easily.