I have an AC180 battery and I’ve purchased 3 x PV120S solar panels.
Todays weather was overcast and so I connected my 3 panels in series the way that bluetti support showed on an image/diagram.
With 1 panel connected I was producing 5w, 2 panels connected I produced 9w and with 3 panels connected the DC light was blinking and I produced 0w.
Hi @Marren2016 the Bluetti in the image is not an AC180. The max VOC (open circuit voltage) for the AC180 is 60V, ideally you want to be 10% under . The panels are nearly 25V each . Combining in series adds the volts together. You can only safely (for your AC180) connect 2 of those panels in series, which will be about 50V. The AC180 can be fatally damaged by going over the VOC.
I cut it down to 2 panels and mixed and matched them and they were fine when it was 2.
The bluetti eBay support said 3 panels were ok.
They have now apologised as that info was incorrect.
Now, I now the voc is 24v but when the weather man says it’s nothing but clouds for days I believe it to be safe to add more than 2 panels in series. If the sun is even slightly off square-on the power drops.
On my panels I can only get 109w each in ideal conditions so as long as I’m drawing -280w it should be safe.
Hi, please don’t use all 3 panels in series, for the reasons stated previously. When the weather is colder the voltage per panel can rise, hence staying 10% under the maximum for the AC180 to keep it safe from over voltage.
When it is cloudy you will get significantly less watts from the panels. Even a cloud passing over on a perfect day will cause the watts to temporarily decrease. This is totally normal with solar charging.
Agree 100% with @Tezzabee, don’t use three panels in series, even on cloudy days. Before the AC180 starts pulling amps, the voltage will be too high.
If you really want to overpanel for cloudy days, I’d recommend getting a fourth panel, and putting them in 2S2P, or two in series, and two in parallel. This will require a set of mc4 splitter. Here’s an example: Amazon.com
If you don’t want to do 2S2P, and If you bought 3 panels based on Bluetti’s suggestion for the AC180, maybe they will let you return the third.
TBF, and I didn’t know this until a month ago but with the sun being as low as it is non of the panels work after 12 noon. There’s my car on the drive, the lampost a bit further away all cast a shadow on the panel. So I don’t have the space for the other 2 panels. Total waste of money in winter. Maybe in summer when we go on camping trips but they’re few & far between. I might ask bluetti if they’ll take one back.
