Elite 200 V2 & MPPT Instability

I’ve been using the Elite 200 v2 power station for a month now.

First of all, I’d like to say that it’s a very good product — especially quiet.

But I’m encountering a small issue with solar charging. It’s being charged by a solar panel (33V-440W). Most of the time, the charging system works well, and I reach around 350W of charging power in sunny conditions.
However, sometimes under the same conditions, the charging system seems to malfunction: it gets stuck at around 100W because the MPPT sets the input voltage to around 16V, which is far from the panel’s optimal voltage.

When this happens, simply unplugging and reconnecting the panel resets the MPPT, and it successfully finds the optimal point again (around 30–32V). Sometimes, the MPPT briefly reaches the optimal voltage, but then inexplicably drops back down, even though sunlight conditions remain constant.

Clearly, the MPPT algorithm has some bugs.
Has anyone else experienced the same issue?

Your panel voltage is hovering at the optimum MPPT voltage, this may clip the current limit if it briefly drops below 32V. Charge rate is also affected by the batteries state of charge.
Solar charging is a highly variable charging source, affected by time of day, weather, temperature and other factors.
As most power stations have an input minimum of 60V, it is always a better option to use 2 nominal 12V panels in series to get a Voc in the mid 40V range, with a Vmp of mid 30sV or higher.
I have a solar mat with a Vmp of 18V running with a Victron MPPT. The Victron requires +5V on battery volts to start charging. This is especially problematic with LFP batteries as the battery voltage may be 13.1 or 13.2V which means the panel has to output 18.1 to 18.2V to start charging which it will not. My only option is to double the Vmp to 36V (2 panels in series) as the Victron has a 75V Voc input limit.
This highlights - It’s not the MPPT or battery at fault.

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Hello
Have you configured “advanced mode” as indicated in the manual to remove the 8A limit for voltages below 30V ?
In the app, set the DC input source to “PV” or “Other” in the advanced mode. The charging strategies for these two sources are shown below:
image

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@Snips1
Yes, I have already try “Other”, “PV”, “PV Pro”. The issue happens in the 3 modes. This happens randomly and infrequently. It can easily go unnoticed.
It realy looks like the mppt’s algorithm has a loophole in some situation. What makes me say this is that if I disconnect, reconnect the PV, the MPPT correctly finds the optimum around 32V.

I don’t have an Elite 200 V2 because I invested (too early) in several AC200max and expansion batteries. However, I encountered the same problems on the MPPT of my AC200max and I noticed that by disconnecting and reconnecting the solar input, suddenly the power can increase significantly. I only have two solutions at hand: you can add a second panel in series to increase the voltage (as Mandp suggests) however in your case it will not be possible to add a second identical panel because I understand that your panel is at 33V (Voc? Vmp?) and with two panels you will exceed the 60V max of the Elite’s solar input. You can try to find a second panel (PV2), different from your first panel (PV1) with a lower Voc, allowing to have Voc(PV1) + Voc(PV2)<60V. And ideally the second PV2 panel should have an Imp(PV2) close to the Imp(PV1) to optimize the power delivered. The other solution I see is to use an external MPPT (for example VICTRON smartsolar 100/20 - 48 V) with a battery charging voltage higher than 30V of course. If not, last solution, if Bluetti technicians are willing to look at your problem and the characteristics of your panel, they may be able to correct the MPPT of the Elite.

Hi @frncschrnvl, We suggest you enable the PV Pro mode. Does this help?

Additionally, you mentioned that the input voltage was 16V before reconnecting the solar panel, and then it increased to 33V. Could you please take screenshots of both values? A video would be even more helpful. Please upload it to Google Drive, and share the link with us, we will further analyze it.

Also, please provide the SN code and the current firmware version, including the BMS firmware, and we will attempt to upgrade the firmware to optimize charging performance.

Thanks to @Mandp and @Snips1 for their analysis and answers.