For the AC200L Custom UPS: the “Charging” slider doesn’t seem to work as expected.
My understanding is:
when Charging is “Off”, the grid will only be used to bypass the load, starting when SOC discharges to the SOC Low threshold. Since the load is bypassed by grid, SOC will remain at SOC Low until solar charges the battery to SOC High.
when Charging is “On”, the grid is used to charge the battery to SOC High, starting when SOC discharges to the SOC Low threshold (is it charges battery in addition to helping bypass the load).
However, when Charging slider is “Off”, the desired behavior doesn’t occur: SOC continues to drift below SOC Low value, all the way until the battery discharges.
In other words, the grid’s bypass load matching isn’t exact and is smaller than the load, so SOC continues to drop forever (though more slowly than if bypassing wasn’t occurring).
For example, I have SOC Low set to 10%. And when SOC reaches 10%, I see grid load bypass turning on, and trying to match my ~100-150W load. But, SOC continues to drop all the way to 5%, since it seems to not be bypassing correctly.
So I had to manually turn the Charging slider to On to prevent the unit from discharging to 0.
Why isn’t SOC staying near 10% when Charging is set to Off?
Is my understanding above correct, on what should occur when Charging slider is set to Off? If so, then the load bypassing isn’t working as expected.
Hi @jCs, We don’t quite understand your settings.
Could you provide a screenshot of your setup and let us know what outcome you’re aiming for? Then, we can recommend the most suitable settings for you.
We are also note sure about what you mean by the “Charging” slider.
Please note the following two points:
The charging time period can be used for charging or bypassing the load. If the SOC is lower than SOC-L during this time, it will charge.
As long as the SOC-L is set, the system will charge from the grid whenever the SOC falls below SOC-L, regardless of the time period.
“We are also note sure about what you mean by the “Charging” slider.”
I’m not sure how to answer better, because by Charging slider, I mean the slider that’s labelled “Charging” in the Customized UPS mode. I’m not sure how else to say what it is
“Could you provide a screenshot of your setup and let us know what outcome you’re aiming for?”
I’m looking for the intended behavior as written in the manual, of SOC not falling significantly below the SOC% threshold that the user sets.
I can’t provide a screenshot at the moment, but here’s a video timestamp back when the slider was called “Charge from Grid”, along with a brief explanation for what it’s supposed to do: https://youtu.be/lENGwfq-MIA?t=2549
" 1. As long as the SOC-L is set, the system will charge from the grid whenever the SOC falls below SOC-L, regardless of the time period."
Understood and I agree this is the intended behavior. But I’m not seeing that: I’m seeing SOC continue to get lower, even though the 200L is trying to match load from the grid. The matching seems it’s not exact, though, since SOC doesn’t stay at SOC-L threshold.
By the way, in PV mode this load bypassing from the grid works fine, and SOC stays around SOC % threshold (with some tiny 1% variation as expected). But in Custom UPS mode, SOC does fall below SOC-L and continues to drop; so the grid is not matching the load and SOC is no staying where it should.
Note: when the Charging slider is set to On, then the 200L does correctly charge to SOC-H and keeps the charge at SOC-H correctly (via bypassing the load). It just doesn’t work when the Charging slider is set to Off – in this case SOC does not stay at SOC-L and continues to fall until 0.
Hi jCs, Based on the screenshot provided by Jeff, it seems you have selected the time control mode.
With this setting, charging from the grid will occur when the SOC drops below 30%. During the charging period, the device can both charge and by pass loads. Typically, charging will stop once the SOC reaches 30% or higher to avoid frequent charge-stop-charge cycles.
When the SOC drops below SOC-L, the battery level continues to decrease. Can you confirm if, when the SOC is below SOC-L, the system only bypasses the load and does not charge? What are your specific time control settings?
If this is the case, please provide the SN code and the current firmware version. It would be even better if you could provide photos or upload a video to a cloud drive and share the link with us.
When the charging slider is off, the system functions in PV priority mode.
Hi @BLUETTI_CARE , no, what he’s showing is Custom UPS mode – not time control mode. You can even see it say “Customized UPS” at the top of the photo under “working mode”.
You can see the Charging slider in your app under customized UPS, right? Not sure why I need to show screenshots…you can just check your own app and you’ll see what i’m talking about
Although as mentioned this is not time control, i’ll try to answer this question: "Can you confirm if, when the SOC is below SOC-L, the system only bypasses the load and does not charge? "
Correct, it does not charge the battery, but seems like it only attempts to bypass the load, but the bypassing doesn’t work since the SOC continues to drop to 0.
“If this is the case, please provide the SN code and the current firmware version.”
BMS: 1043.13
DPS: 2098.22
S/N: 2439000825420
Hi @jCs, Thank you for getting back to us so quickly.
To avoid frequent relay switching, charging will not immediately start when the battery is below 30%, nor will it stop immediately when it’s above 30%. Instead, there is a margin. Charging typically begins when the battery is around 28% and stops at approximately 32% or 33%.
Regarding the SOC dropping to a very low level without charging, did any error codes appear at that time? We guess it may have been caused by high temperature or a brief interruption in the power supply from the grid, which prevented charging.
We have confirmed that your firmware is up to date, and currently, there are no further updates available.
@BLUETTI_CARE there were no error codes, and it’s in a nice cool (but not cold) dry location – it not hot location. There was also no interruption from the grid.
Agreed that variation is expected, but this variation was so large that the battery went to 0. I can repeat the test if you’d like, but custom UPS mode doesn’t seem to work when the Charging slide is set to Off.
Hi @jCs, Thank you for letting us know.
Since there is no error code, it seems everything is running normally and there is no issue.
I appreciate your kind understanding and patience.
@BLUETTI_CARE No, it’s not running normally, and there is an issue: the charge drops to 0 as mentioned. Is this the desired behavior?
Or maybe I misunderstood your comment, and you all are looking into the issue? It wasn’t clear
Hi @jCs, We find it a bit challenging to fully understand your description, and we’d still like to know more about your specific UPS setup. If possible, providing detailed screenshots or a video would be even better.
Alternatively, you could try switching to the standard UPS mode and check if the issue persists.
In general, if there are no error codes, it typically means there are no faults.
@BLUETTI_CARE Sure, I will try to take a video or screenshot.
But also, I’ll ask specifically: is the intended behavior when Charging slider is set to On, that the battery discharges to 0? I assume the SOC is meant to float around the SOC threshold given that you mentioned: “Charging typically begins when the battery is around 28% and stops at approximately 32% or 33%”.
As far as I can tell, the issue does not exist in other modes. As mentioned in my post, the issue is only with Charging slider set to On, when in Custom UPS mode. But since UPS mode is not useful for me, Custom UPS should be fixed.
Well, as these forums have shown there are a very large number of Bluetti bugs that do not show error codes , yet they are problems that need to be resolved. So “no error codes” doesn’t mean the system is working as intended/designed or doesn’t have faults…
Hi @jCs, Yes, we are indeed unclear about your issue. It is very rare for only the Custom UPS mode to have a problem, while other modes work fine.
Therefore, we really need the specific video you mentioned. The video needs to include the main interface, UPS mode, and advanced settings.
This will allow us to understand your settings clearly and determine the solution accordingly.
I appreciate your kind understanding and patience.
