Strange/ false input and tempature readings

When I am charging with solar a few (interrelated) bugs are happening.
First, the battery does not automatically turn on when it starts receiving power.
2nd, it reads 0 watts, and a very low voltage, ranging about 5 to 12, when I typically get 40-60, and it reads 0 amps. However, I know it is getting power because if I walk away for an hour or so and come back the battery goes up 5-10% in charge level, very strange.
3rd, the tempature readings variy a lot. For example PV says 21 degrees C, DC says 22 and AC says 30, and the BMS mantiance page reads 11, the closest of these to actual room tempature being the BMS page.

I am doing nothing differnt, these issues seem to have arrisen from thin air, the device stills functions as a battery, reciving power and discharging it but id like to resolve or at least understand these issues, espcially the imput power reading, I dont care so much about tempature because I know if its freezing cold out or not.

What is the actual temperature where the AC200 is located when you are charging? My first thought is that it is very low and that is causing problems.

You mention nothing about what kind of panels you are charging from, their specs.
How the panels are connected.
Did this issue just appear and you were able to charge normally before or has this issue been there ever since day 1?
If you try car charge mode and connect to your vehicle does the unit charge normally? (trying to determine if it is a panel issue).
If you have the second charging brick and connect it to the solar input do you see the same voltage and amp issues or does it charge fine?

If it charges fine through the same port via other charging sources, the issue is most likely your panels, connections or wiring. Some more detail will help to diagnose

If the AC200 is actually cold, try warming it up and charging again with the same set up to see if the environment is the issue. A cold AC200 will not charge correctly and will not operate normally.

thanks for the sugestions ill try charging from a car and see what happens. Ill keep you posted.

I have the wall socket charging brick that runs into the other input port but I do not know of a solar/ car charging brick (large black peice) that I can plug into the PV adapter. Using the wall socket charging brick it shows watts, amps and volts just fine.

Yes the strange thing is that the issue appeared without me making any changes to the 3 solar panals in series I had hooked up before, my routine is to store the ac200p in my room at night, and every morning I bring it out to my covered porch and plug it in, one morning it just stopped reading watts/volts/amps like it was before.

The tempature ranges from about 30-70 degrees F around here, it sometimes just barly hits freezing outside at night which is why I keep it indoors at night, when I bring it out in the morning its always above freezing by then, usually about 36-40.

my panals are old and usually put out in full sun 15-25 volts each, I wire (10 guage and some 8 guage) in series with terminals going to the junction boxes, and one positive and one negitive of the wires have MC4 so they can connect to the MC4 that came with the bluetti. so its certainly possible that could be the issue, if the car charging works ill dubble check my panals and wiring, but what is so strange to me is that it is in fact charging, as indicated by the increasing battery % throughout the day. Before it would read about 40-70 amps depending on sun intensity, now with the same conditions its about 5-12 volts and no amps, yet its clearly reciving a lot more power than just a few volts, otherwise it would not be charging… this is whats really odd to me. Anyway next step is the car charger test, just have to wait till it stops raining

If you have the ac200 set to CAR charging mode and your panels really are outputting 12 volts at any time, the ac200 would charge from the panels just like car mode. That could explain why the percentage is going up. You will be unable to connect your power brick to the PV input port without the 7909 female to XT90 adapter that comes with a second power brick.

I just tried out charging it from the car, and that function works fine, so the the cable and connection must be solid. I am sure that when I was charging from solar it was set on the PV setting, being very aware of that because that was my orginal simple hickup, not knowing there are differnt setting for PV and car. Anyway next I am waiting for a sunny day and then I am going to check my solar setup, make sure the connections are good and try some differnt combinations of panals.

The car cable, connections and charging system seem solid. That leaves the solar panels and the MC4 to XT90 cable as suspects. My bet is on the solar panels or their connections (connectors) as being the most likely problem. Solar panels can output voltage with almost no amperge which can be confusing when you are using a meter on each connection to see if there is power.

yeah that makes sense, since im working with old panals i got for free, so im going to buy a nice new one and see if that helps, maybe the amperage just isnt strong enough to trigger a reading, even though im getting power.

Remember, you need a minimum of 35 volts of solar output for any charging to occur. This usually means at least two panels conected in series unless you have one very large panel with an output of 35+ volts.

yeah thats important to keep in mind, im going to hook in to the other 4 panels iv got going in series and see what happens, so the 5 total should really kick it into gear and tell me if the current panals have become extremely weak overnight… I was getting about 40-70 volts and then one day I plug in and reads only about 6-15, but still charging. Today, I got sun and something differnt happened, same voltage reading but now the battery charge % is no longer increasing over time, so at the first stage of this issue I was getting a low reading by plenty of power, now I get that same reading but no power, which makes more sense if the reading is right, 6-15 volts is obviously under that 35 miniumum. Anyway ill check back in a few weeks from now when I get a 180 watt panal and wire in series with what iv got going.

If you have bad wiring or bad panel; connecting a good panel to bad wiring or bad panel will still give you a bad result

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of course, but appreciate all the advice. the wires are very new but if I am still having problems with a new panel I will consider this


Just chiming in Isaac, to support and underscore Scott’s experienced recommendation to use good equipment and to have sound wiring and sound connections and to also hope that you resolve your solar issues soon.

I believe that the extra $ invested in good equipment and high quality connectors and taking the extra time to insure that all connections are exactly right, makes a big difference in the long run.

As a recreational Cape Cod Bay mariner, I’ve learned to fabricate with redundancy by using higher gauge wire and higher quality connectors and to invest extra time to make sure all is correct, secure and sea worthy.

I’m new to solar but confidant that this methodology during my education, will insure success and deliver long term reliability.

I’m sure you will get this nailed Isaac.



hey guys I finally got it figured out. Was a faulty connection, simple as that. This morning the sun came out so I unwired everything and put it all back together again, redid a couple janky connections and as I was messing around one wire slipped out of its terminal, and I realized that was the problem. It was quite literally hanging on by a thread, which would explain why I was getting really low voltage but still some, and why it appeared to just stop working without me making any changes. Thanks for thinking it through with me scott.

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My pleasure. It is usually the easy things that cause the biggest issues. You can get good voltage with a bad connection and almost no amperage to charge. That appears to have been the case. Glad you got it figured out and have your confidence regained in your Bluetti AC200P.

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