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Question:
I got an AC300+B300 set that I currently use as emergency power source.
I also rent 6 rooftop solar panels that are grid connected via a Solis Mini 1500 solar inverter.
During power outages, can I plug my rooftop solar panels into my AC300?
If yes, Which cables do I need to connect my solar panels to my AC300? I need to buy a 10 meter long DC extension cable to connect my solar panels to my AC300.
If no, do I need additional hardware or converters before I can plug my rooftop solar panels into my AC300?
It would be nice if I can recharge my AC300 during power outages via my rooftop solar panels.
I don’t know much about the technicals about solar panels installations. Everything was installed for me by the company I rent it from.
First impressions of Bluetti SP120L portable solar panel.
I was very lucky to win this panel in the recent #BLUETTIXASHomeParty competition. Unfortunately the UK winter weather hasn’t been cooperative, but I did manage to unpack the panel indoors and get a good look at it.
This is my first Bluetti panel, but I do have others to compare it to. First impressions are that the panel is sturdy and well made. The design is well thought out and practical.
The leads are contained in a handy, fitted pouch which has extra room for your Bluetti’s solar cable or other small accessories. Importantly, the specs are included inside in an easy to read size.
Being a fan of shiny things, I find the popper type closures for when the panel is folded aesthetically pleasing. They’re also strong.
The panel is IP67 rated, so no panic in a light shower, but is not for permanent installation or leaving out in heavy rain. Nicely thick plastic is used for the handle, and at other crucial points.
The SP120L has 3 study supports. I really like the design.
There are handy angle labels and a simple elasticated hook to select the angle and keep the support in place.
No idea why it only wants to upoload upside down haha, but the pic is to show how flat the panel lays due to the well designed supports.
And most importantly for me - will the SP120L fit in my bike trailer for easy, environmentally friendly transportation. Its a definite yes (although it will be padded and wrapped for its real journey).
All in all I really like this panel and look forward to sunny days when it will be travelling to the allotment and feeding my smaller Bluettis.
The AC300 does have two MPPTs with each 150V voc. So it would be interesting to know, how the six panels are wired. When you have 2 pairs with each three panels, it should work to connect Pair 1 to MPPT 1 and Pair 2 to MPPT 2. Make sure that the voc of the three panels in series dont exceed the 150V. If you have all six panel wired together, im really sure you over 150V and cant use it.
The AC300 have a MC4 Plug to connect a solar panel, so the same plug the most solarpanels use out of the box. If you use a serial connection, there isnt any additional hardware needed, just a cable pair (or two when have 2 pairs) that connect directly to the AC300.
If all six panels wired together, than the voc of the panels are likely to be more than 150V. Do use the panels with the AC300, you need a voltage step down module (Like the D300S) This would convert up to 500V down to about 120V
How many cable pairs going to your mini inverter? You can measure the voltage with a multimeter.
There are only two DC cables coming from my solar panels to my inverter. A red one and a black one with MC4 connectors. So that’s probably 6 rigid solar panels in series?
I’s currently winter and very cloudy/misty weather in The Netherlands. I’ll have to wait for a sunny summer day to measure the maximum voltage of my solar panel setup.
So I may need a step down module when the voltage gets over 150V. The Bluetti D300S is very expensive for an occasional use that I need. I hope I won’t have too many power outages that last longer than the usage time of my two B300 batteries. Are there any alternatives for the D300S that are significantly lower priced?
But I will need to do a voltage test first to verify if I really need one. To be continued.
The voltage now is a lot lower than in the summer. True. But you could meassure the voltage to know atleast a approximate value. When you meassure like 100V in this conditions, then in summer the six panels propaly will deliever 150V or more.
Unfortunately i dont know any other step down module than the D300S. When you look for yourself, its important to see the maximum input voc and the Voltage outout of the module.
Well. I tested it and it’s 177V DC already on a cloudy winter day. So it already is over the limit of 150V. SO that means I need the D300S or similar if I want to charge it using my solar panels but fir the few times I’m going to use it that way that is a solution that is too expensive. Perhaps if I ever get into a situation like Ukraine is facing right now the story changes. But I expect and hope I will never need that.
As I have mentioned before, solar panels have a temperature coefficient of around 0.2%. The tested Voc is usually performed at 25 degrees C (77F). For every degree warmer than 25C the Voc will decrease, conversely, for every degree below 25C the Voc will increase. This applies particularly in sunny conditions, but can occur in overcast weather.
The net result is that in a nominal 12V panel with a 25C tested Voc of 24V, at zero degrees C the Voc can be 30V. The effect is per panel, which means in series connected panels the affect is cumulative.
Good v bad weather affects the power output i.e. watts. In bright sun as is in Australia at the moment, the wattage output is very high, however, when it it is 40 degrees C in the shade, the Voc reduces. In winter time at near zero C, or single digit temperatures the Voc is higher, but the wattage output is significantly reduced especially in overcast conditions.
Gday all, I just received an AC240 and hopefully I can show you the perfect panels to get very close to the 1200w input limit @ less than the VOC of 60v
I am an Aussie and I dunno if can source these but I think with some effort it would be possible.
These panels are Jinkos , good panels all around. Now these are residential panels so large, weighty and efficient. 2 in parallel should do the trick. You are welcome. https://jinkosolar.eu/wp-content/uploads/JKM605-625N-78HL4-BDV-F4-EN-1.pdf
G’day All. I am not an Aussie, but a disillusioned Brit. (Born in Wales, Scottish heritage, brought up in England, but relate to the Irish.)
Presently in our pleasant (or not) island it is pointless to bring out my PV350 panels, as, if by chance there is any sun, I’ll only draw about 70 watts at best. But planning ahead some advice please, if poss.
When the solar power gets a wee bit stronger I’d like to rig up my PV 350 panels so i can leave them out in the elements on a permanent basis. But i remember reading that it is advisable not to leave them out, especially in the rain. Does any one have any suggestions of how I could weatherproof the panels, short of leaving the country for warmer climes.
Would appreciate your help here folks.
Yours. Andy.
Leave your PV350 panels for mobile and camping use. You can leave them in the rain on a temporary basis. Watch out for strong winds because those can absolutely blow your mobile solar panels away.
For permanent use, get sturdy rooftop solar panels and mount them on something fixed. That can be a vehicle. Those rooftop panels are both cheaper and they are designed to be left in the infamous English weather.
Thank you Le Reynard Rapide (QuickFox).
Yup, that’s what I must do.
And thank you previously for bringing to my attention the need to recalibrate every few months (0 to 100). And also for your metaphor regarding usage comparing to one’s motor usage. I live off grid, which speaks for itself regarding usage.
Andy.
Hello All.
Living off grid I am solely reliant on my AC200L & support B300K, which is quite satisfactory for my needs. As previously said, at this time in Southern England, I use my generator to recharge. But thinking ahead, as advised, I want to position solar panels on my, conveniently, South facing gabled roof. I would like to power up my system as swiftly as possible, when our weather gives the opportunity, but can one overdo the potential wattage coming into the system?
Appreciate your help lovely people.
Andy.
Having more wattage and/or current available from the solar panels is not only fine, but can be an effective way to get longer periods of full solar power. What you never want to do is have more voltage (looking at the Voc rating) from the panels than what the power station is rated for. Even more specifically, since solar panels can generate more voltage in cold weather than in warm weather, it may be necessary to remain at or below about 80% of the power station’s maximum solar panel voltage rating.
The reason is that the power station’s solar charge controller will regulate the current used for charging, but it cannot affect the voltage being supplied. Too much voltage will damage the charging circuit.
So on your solar panels you need to find the “open circuit voltage”, referred to as Voc, and use that to determine how many panels can be put in series before the voltage is too high.
I will use my own system as an example. I have an AC300 with 4 B300 batteries, so it can take two solar arrays, up to 1200 watts each, and up to 150 volts. I have two arrays, both are identical so I will discuss just one. My 250 watt solar panels have a Voc of 37 volts. So putting 3 in series gets me to 111 volts, but 4 in series is too much voltage because 148 volts is too close to the 150 volt maximum, and where I live it can get well below freezing. So 3 in series is my limit. But that is only 750 watts out of 1200 maximum. So I took another three panels in series and put those in parallel with the first three. So the maximum voltage remains at 111 volts (series adds voltage of the panels, parallel add the current), but the maximum current doubles, and the maximum wattage of the array is now 1500 watts. My charge controller will limit that to 1200 watts, but the array will reach 1200 watts for a longer period of time while the sun’s power is not at it’s maximum.
Since I have two such arrays I have 3000 watts of solar power for a system that can use up to 2400 watts, and it works beautifully.
GDay Andy,
The PV350 (and all folding solar panels) are designed for temporary use only. And its not actually the panels not being waterproof being the issue (They’re actually IP65 rated so are definitely fine with getting a little wet). The issue is that to be made portable and light, all folding panels use fabric and plastics to support the frame (great idea as it can over halve the weight!). However good these materials are, they just cannot compete with things like aluminium frames for constant exposure to UV.
So if you left them out you would find the actual solar cells be fine (ETFE panels are wonderfully durable), but the fabric would fade, and deteriorate after a few weeks/months.
If you’re wishing for a semi permanent setup, I’d suggesting one of the two options, based on what power station you’re charging with these panels:
If your station supports less than 50v max PV voltage, then look into some automotive solar panels (Aluminium frame) or some rigid folding panels (Aluminium frame). These usually have a max PV of about 20v (ish). They will be heavier and bulkier than the PV350 but they are designed to live outdoors on a more permanent basis.
If your station supports 50V max PV or higher, then look into house based panels (if you’re on a budget these can be had dirt cheap second hand, In Australia I regularly buy panels for around $50 for 300w panels second hand.). These will be large single panels. But they’re built tough and often have lots of life left in them.
Both of these options leave your PV350 for when you need portable power, as nothing will compete with it for portability,
Sam.
Thanking you kindly for this. Aluminium, I’m reckoning, as on a static caravan roof.
Will no doubt be wanting verification that my choice is a compatible one before purchase.
Cheers brother.
Andy.
Welcome to the Solar Panel Q&A List thread! 
To streamline the forum and prioritize valuable discussions, we have created this dedicated space for all your questions and inquiries related to solar panels.
