I have had my AC300 for about a month with no solar connected and it has been working fine. Yesterday I switched my solar panels to the AC300 and I have been having a few issues.
Issue 1 - When enabling AC and adding some AC load the PV input drops to about 250 Watts and won’t go up again until after I turn off AC output.
Issue 2 - The MPPT tracker on the AC300 doesn’t track as well as the AC200MAX. If I unplug the panels from the AC300 and plug them into the AC200MAX I get better results (+200 Watts). I am not Amp limited at those times. It is around 9 Amps on the AC200MAX.
I have two arrays
Input 1 - 3 x Phono Draco 420W in series Normal Operating Voltage 100V. VOC 113V.
Input 2 - 2 x LONGi Hi-MO 6 435WP in series Normal operating Voltage 66V. VOC 76V.
DSP has upgraded to v4036.10. It is a little better, but still feels off. Now when enabling AC output the Solar does not drop to 250 Watts in fact it often jumps up higher than with AC output off. However when turning off AC output it messes up the solar tracking and drops down for a minute or so before climbing again. It seems the AC300 DC input and AC output are very much linked on the AC300 as in they are negotiating somehow and have rules governing their joint behaviour. Perhaps this is something to do with the UPS, but as I am unable to disable the UPS I am not sure. I am in standard UPS mode but unplugged from grid
Some things I have noticed with the AC300 perhaps you can help explain the rules governing this behaviour.
Enabling or disabling AC output load directly effects solar input.
Solar input is throttling when battery is around 90% or more, but solar input increases when a load is applied to AC output.
When both arrays were getting sun the AC300 seemed to be limiting the total solar input to 1000 watts which was about 6 Amps from each array. Exactly half the 12 Amps maximum.
24v DC output is not very stable when AC output is enabled and a medium load of 600 watts is being drawn from AC. The DC voltage fluctuates between 20v and 24V and 200 - 250 Watts. When AC output is disabled the DC output is rock solid stable at 24V 250 Watts.
My AC200MAX works completely differently. It continues to pull full solar until fully charged and does not throttle input. AC output doesn’t change the solar input at all and I am able to input 920 watts from solar while outputting 2200 watts AC.
Is my AC300 broken because I haven’t seen this issue on video reviews of the AC300, but the Firmware upgrade did change the behaviour which makes me think it could be a software issue? I have reset the unit in the menu a few times but it doesn’t change behaviour.
@Sideeffect Thanks for your feedback. I will check with our technicians to see if new firmware is available. If I have any updates I’ll let you know ASAP.
When the battery charge is approximately 90% or higher, enabling or disabling the AC output load directly affects the solar input.
Disabling the AC output load is equivalent to only charging, while enabling the AC output load not only charges, but also bypasses the load, so the PV input power will be higher after turning on the AC.
For the No4, our technician is trying to reproduce the problem, can you take a video for us?
When the battery charge is approximately 90% or higher, enabling or disabling the AC output load directly affects the solar input.
Disabling the AC output load is equivalent to only charging, while enabling the AC output load not only charges, but also bypasses the load, so the PV input power will be higher after turning on the AC.
There has been a bit more sun these last weeks so I have been able to observe the solar charging a bit. When the charge level is at 85% it starts to do some minor throttling for example 1600 watts of solar will drop to 1200 watts if there is no AC output. If I enable AC output the solar charge will increase back to 1600 watts. I guess this is battery protection/charge limitation and the speed is also throttled like this from AC charge so I understand why this is happening.
At 90% the throttling is very severe and most of the solar potential is lost. I am just learning to work around it by adding more AC load at levels of higher battery charge so that the solar is power is not wasted.
I am still having an issue with by B300 battery where it continues to go out of calibration and so it will jump from 92% to 100% charge. Perhaps this is why it is throttling so severely at 90%. I calibrate it every so often but it drifts again soon after I wonder if this is because I have a lead acid UPS connected that has an apparent power higher than the real power. Does the Bluetti AC300 calibrate itself from voltage level or from the Watts it thinks it has output?
After the AC is turned on, the voltage of the DC port will also be slightly affected. Because the DC output terminal cannot completely filter the AC, the output voltage of the cigarette lighter will fluctuate from time to time.
The charging end jumps to 100% because the SOC is inaccurate. The machine calibrates the SOC by itself. When the machine detects that the actual voltage is already very high, it will automatically calibrate the SOC to 100% if it does not continue charging.
The reason I’m asking is that my solar charging seems erratic and I’m wondering if this will help. I have just installed solar panels and it’s difficult to troubleshoot anything. Here’s a snapshot of what’s going on.
Whether the changing solar charging is an issue or normal depends entirely on what the sun conditions outside where at the time. If there’s any amount of clouds then the solar intensity will be changing constantly.
Assuming for a moment that it was to some degree cloudy, then this is demonstrating why we need MPPT charge controllers with solar panels, because the output power of the panels are not a constant in the way that a power supply or battery will be.
Here’s an example of changing solar conditions at my home taken from my home weather station.
Ok, one more edit, here’s what a decent sunny day looks like. You’ll notice that even then the peaks where lower on this day, but that is likely due to the affect of reflections from clouds brightening the panels on the cloudy days.
Thanks for the information. These panels seem to be extremely sensitive to shade. I adjusted them a bit and got them more stable and to at an acceptable wattage.
The tracking is from the Home Assistant Bluetti2MQTT addon.
