AC200P Speculation - SD Card?

Behind the LCD screen on the AC200P I believe I found an SD card. My first thought was Firmware loading and maybe potential to upgrade firmware via SD card.

Anyone else care to speculate?


@bigbluefan That would be amazing if this along with the OG AC200 had the availability to update firmware!!

Maybe @BLUETTI can let us know what this is all about?!! :kissing_heart:


@bigbluefan I followed the paths all over that board and I don’t see it but I believe you. Of course I’m presuming it looks like most SD card slots on a board…but I could b wrong.

In any case not sure how that would b helpful if there is no connectivity to update the SD card if it is firmware. And I don’t see most peeps taking apart their ac200/p to replace an SD card w/ new firmware (mailed by bluetti ?? to existing owners don’t really see that happening either).

But in a pinch if it is firmware it could give us hope dealing w/ serious issue if no other option so I’m curious to hear @BLUETTI response.



Yea not sure. It is a weird spot for it, just found it really interesting on the placement. Not on the main board.

Now looking at it, maybe theres an ESP8266 (ESP01) soldered on there in a custom PCB?

Wifi capable even?

USP82666 - pin layout and antenna

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I know that some products offer monitoring by the Bluetti app through a WiFi network. Download and install that app and see what information you can gather.

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Interesting. I’m sure they have boards they haven’t yet decided how they would exploit. But I know my ac200/p was early in the curve and I think bluetti is trying incorporate features that will provide more flexibility. I’m just glad I have it and real happy bluetti didn’t forget who they brung to the dance (ac200/ac200p) and made the expansion batteries backward compatible…in my book bluetti earned big props on that move !!! And more of my business/ loyalty. @bigbluefan


Yea, I have seen some interesting things.
For example the gave the capabilities to this BMS board to run 16S or 14s.

And plenty of extra unsoldered connections for different setups


Yeah but I don’t believe it applies to the ac200/p models. I wish it did. @Raymondjram @bigbluefan @m.briney

They seem to be a company that has vision…kinda rare these days


Are the expansion batteries actually backward compatible? That is, the provided a unregulated output that goes straight to the battery on the other side. Or so they provide an DC output (potentially regulated) that plugs into the DC input so it charges the other battery.

The difference is the efficiency. Direct battery connection would be near 100% efficient. Regulated DC out to DC in to charge the battery maybe 75%, unregulated DC out to DC in to charge the battery maybe 85%.

It would be interesting to test the output capacity of a AC200p by itself and when it is chained to a fully charged B230.


As I see in the B300 manual, there seems to be a direct bus supplying power between them and the AC300 or other controller when jumpered together, such as a “daisy chain”. So yes there may be the maximum power flow with very little loss and high efficiency.

I do believe it is a direct connect between the B230/B300 with the AC300 and AC200max, as they have a dedicated battery connection terminal. However I am no so sure between those battery units and the AC200/P

Main board on the AC 200p only has one set of terminals for the main battery.

The board itself has a second set of non-soldered terminals.

So if that’s hooked up in the new units to a direct battery terminal I could see it being a direct connection.