D300S does not work anymore

Product Discussion BLUETTI AC Series
1

Since half a year I have my AC500 running together with 3 B300S and the step down module D300S.

Today, I got the problem that there is no PV input given to the AC500 anymore.

When connected to the d300s both only 1 out of the 2 inputs show voltage. The other one nothing. When disconnected than both show about 300V.

Does anybody here has an idea why there is this problem?

Idea was to add some of the new B300K. However, no that the d300s shows this problem I cannot even charge the existing ones :-(

I would appreciate any help.

Best regards
Chris

2

@BLUETTI_CARE or @BLUETTI : could you please support?

I’d appreciate your help
Thanks

3

Can you charge your batteries with the AC500 via utility power?

4

Yep, plug it into a wall outlet and go to your APP UPS settings, PV Priority, and select the minimum SOC you want your batteries charged to. Anywhere from 0 to 100%.

5

I have no connection given to regular grid (fortunately since a few months :-) )

And nothing changed until no power was given into the AC500 anymore suddenly yesterday :-(

I was really surprised that the one string showed me correct voltage but the other one nothing.

When measured at both outputs of D300S there is also no voltage measurable (as also given on AC500 display solar input overview)

Is this a hint for internal short within the D300S step down converter?

Best regards
Chris

6

Hi @ChrisKu, Could you please provide more details so we can help troubleshoot the issue?

When you mentioned that only one string showed the correct voltage, what was the specific voltage displayed? If you swap the connection order of DC1 and DC2 on the AC500 to the D300S, does the voltage appear on the other input instead?

Do you have some other solar panels with VOC values between 12-150V? If so, please try connecting them directly to the AC500 PV input. Does this resolve the issue?

Additionally, is your D300S grounded? If you disconnect the grounding, does it function normally?

Lastly, please share the AC500’s SN number and its current firmware version. If possible, providing videos or pictures would be greatly appreciated to help us better understand the situation.

7

Sorry for the delayed feedback. Was on business trip over the last days.

When I made the picture to answer your questions I saw an oily leakage below the D300S.

So I took it from the wall and it seems that there is more of these coming out of the device :frowning:

IMG_20241207_080318
IMG_20241207_0803183472×4624 748 KB

8

Hey again!


In the meantime I also ordered a new D300S (that arrived today) to quickly find a solution to charge again.
Now I can see that both inputs of the AC500 show about 125V given from the D300S that is connected to the two solar arrays with about 280-300V). However, no wattage is given and it is not charging the batteries.

grafik


Connected to another source it is the same. Voltage is visible, wattage not. However, this source connected directly with B300S input works fine. The battery is charged then regularly.
grafik


What’s also a bit strange: When I connect D300S and AC500 using just PV1 (instead of both PV1 and PV2 inputs) it seems that there is also about 10V given on second DC inpu, even it is not connected. When I swap PV1 and PV2 it is given other way around.

grafik

In regard to grounding: I disconnected grounding of the D300S to test what happens. But nothing changes, even when D300S turned off/on again and also AC500 turned off/on.

I also tested charging via grid. This works as usual.
grafik

So the question is if the D300S really is the problem or if it is the AC500 (with its PV inputs) itself that creates the issue.

@BLUETTI_CARE: would be great if you could further support.
The SN you requested is: AC5002249000465892

IOT: v9041,10
ARM: v4048,04
DSP v4057,01
BMS: v1022,09 (for all three bateries)


I’d appreciate your feedback and help
Thanks and best regards
Chris

9

Hi @ChrisKu, We have applied to push the new firmware DSP v4057.30 for you, which will optimize PV charging performance. The update will be completed within 24 hours. Please upgrade tomorrow and ensure no load is connected during the update.

It appears that the D300S is damaged. Please do not use it any further and contact customer service to arrange warranty service.