I am new to this and looking for a portable panel to back up my180p. I have read all the comments and am now totally confused.
Is it better to link two 100W panels or buy a 200W?
If I stretch to a 220W is that a waste because the 180 only takes up to 160W?
Which is better, Renogy or BLUETTI?
I’m in the uk so expect a full charge but just enough to keep the power station ticking over for an extra day…
Any help is much appreciated!
Hi @Shuxen
first off all, welcome to the bluetti community forum!
The AC180P have the following Solarinput:
500 W max., VOC 12-60 VDC, 10 A
The most critical value is the Open Circuit Voltage (VOC). The 60V are the absolute limit you can connect to the AC180P. So first check the parameters of the panel you want to connect
When its within the 60V (connecting two or more panels in series add voltage), then you good to go. It doesnt really matter if you use one 200W Panel or two 100W Panels. It depends on the available space, shadows and length of the solar cabels.
Generally speaking, more voltage means thinner cables for the same amount of power you want to transfer. So when two panels connected together have a highger voltage and there arent any shadows on one of the panels, i would go that way.
If you space is limited and and of the panels always will have some shadows, than go with the single panel.
greetings
Erik
Thank you very much, that explains the voltage to me now, less resistance. Do smaller units not take 47v? Is that why the higher voltage panel is cheaper? Obviously I want to buy the cheaper one but it looks too good to be true at half the price for the same wattage. Am I missing something else here?
Sorry, I’m talking about a vtoman 220w pro 47v @ £151 versus a vtoman 220w 19v @ £300. It doesn’t make sense to me
Smaller units mostly take up to 28V, Mid range units about 60V and the big ones ~150V.
I think its all about storage and demand. Maybe the high voltage panels arent as popular as the normal ones.
The main reason could be less possibilities. You only can connect one of the 47V Panels but three of the 19V Panel which means you can add more power to it.
Ok thanks very much. Do you think just one 220 would be reasonable enough on its own to give some power to the 180?
Correct me if I’m wrong but 3 would be unsafe as the resistance would increase every degree below 25C. At 0C it would be around 20.6V which puts it over the 60V limit. Granted this is something you would only experience in extreme cold, but you should also factor in a buffer for temperature coefficient as well to be safe. I believe its around +0.35% increase for every 1C below 25C or so but depends on each panel. So if its 0C in the UK, you would take 0.35% of 19V, then multiply that number by 25. (0.0035X19X25= 1.66625V increase). Now you are at 20.66V for each panel, and 3 is over 60 :( You would be able to use that configuration in warmer months though.
Is it better to link two 100W panels or buy a 200W?
The benefit of distributing smaller panels across your solar array is weight advantages. A 100 watt folding panel may weight less than 10 lbs, but 200+ watt ones can go upward of 20 lbs or more. If you buy a rigid panel that’s ground mounted, then its a fixed panel, and weight is not an issue. You want longevity. Something that is made to stand outside all day everyday rain, snow, sunshine. You get whatever is best and whatever you can afford at that point. I would advise toward getting 200 watt panel as an initial investment cost, because you can string 2 together in series and utilize more of the potential of the AC180.
Which is better, Renogy or BLUETTI?
Both are reputable companies, but I would say the best depends on which one honors its warranty or return policy in the least amount of friction. In today’s age they always make it super simple to buy things, but an extreme hassle to return or they cut costs and make you return the item at YOUR expense. I bought a cheap Chinese folding solar blanket a few years back at a really good deal, but it turned out to be crap for performance (rarely netted me over 50% of its rated capacity) and to return it I would have had to pay for shipping back to China, which is a 33% loss to me! Ridiculous. I put some weight on honest customer testimonials, but I don’t rely on them. There are a ton of YouTubers who use affiliate links to solicit and do not give their honest feedback about the product. They are not true users of the product and are nothing but low level marketers. It’s like when a car salesman tells you we “can” or we “might be able to”. Sorry I’m looking at “you will”.
I’m in the uk so expect a full charge but just enough to keep the power station ticking over for an extra day…
I take it by this statement you mean that you don’t plan to use it often (or use it very little?), but just want to keep the battery topped off within a single day. Keep in mind if you always leave the power station at 100% state of charge, it will eventually become mis calibrated. If this happens at the wrong time during an outage, you could be using your power station and it’s chugging along at 85%, then all of a sudden it dips to 25%! It’s out of calibration. There is very little voltage difference between 30% and 80% and sometimes the BMS sucks to be frank. I learned over the years you have to completely discharge the battery from time to time to keep it accurate. If you plan to store the battery long term and not use it for months, its best to keep the state of charge around 60-70% and not 100% for battery health reasons. So decide if you are going to use it… occasionally fully discharge it every 3 months or 6 months. If not, just keep it at 70% and store it long term.
Great advice thanks very much. I’m just using it for a day or two every couple of weeks or so. Short breaks away in between work. Iv ordered a 220w 47v panel for now so won’t be able to add panels but at the price it’s worth seeing if it’s enough. It’s trial and error too I guess but knowing not to keep topping up the charge and letting the 180 run out and then charging is not something I would think of, so thank you!
You right. 3 panels could be lead to overvoltage. As colder it gets from 25c as more voltage can produced by a single panel