I wanted 1000watts and ordered 10 12v 100watt panels. Upon receipt and reading the instructions it says: the max parallel no more than 4, max in series no more than 12. Is this even possible? Have they reversed what is actually meant. The max in series should be 4 to my knowledge giving 48v. And if I can only parallel up to 4, why did I buy 10? What do I do about this? I tried contacting the company already. Now I am hoping perhaps an expert can give advice on the matter. Thank you.
1000watt panel system with 10 100watt panels
- Thread starter Tbleppy
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I think the first step is to slow down and make sure you know what you are doing and what you are ordering before you buy anything else.
Would you start by explaining what you have purchased so far (beyond the solar panels), and what you are trying to do?
In regards to series and parallel, usually that is constrained by the charge controller, at least for smaller systems.
Would you start by explaining what you have purchased so far (beyond the solar panels), and what you are trying to do?
In regards to series and parallel, usually that is constrained by the charge controller, at least for smaller systems.
What is the company?
Website link?
Where are you installing these panels?
100w panels are about 18Vmp so 4 in Series is 72V not 48V.
What brand and model is your 40A SCC?
Starting new threads and not including all your info is not helpful.
Solar upgrade question, I am new to this
I have 200 watts, 1000 inverter, 2 100ah batteries, pwm charge controller all 12v. I am looking to upgrade the system. I am not good with numbers, math, engineering and am seeking help. All I power right now is lights. This is off grid. I want to be able to power a fridge/freezer, lights...
diysolarforum.com
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Yes, of course. The panels are WEIZE 12V 100W Monocrystaline, 2 pack. I ordered 5 2 packs for 10 total panels:
I ordered a Renogy Rover 40 Amp MPPT solar charge controller battery regulator with LCD display:
I ordered 4 LiFePO4 Deep Cycle Battery 12V 100Ah ith built in BMS:
I still plan to purchase an inverter and cables.
My goal is to at least power lights, a freezer and hopefully a well pump although I could settle without the well pump if need be.
Right now I have 200 watt polycrystalline panels running to 2 3 year old deep cycle agm gel batteries with pwm charge controller and 1000W pure sine inverter using 12 awg cables. I power lights with that. Ideally this upgrade would be able to power a freezer(120v 1A AC), countertop dishwasher(1160watts), portable washing machine(220Watts). I will disregard everything except the freezer if need be. I wanted to switch to solar with my well pump which currently runs off a generator but I dont know specs of the pump except its 300 ft deep, travels 100 feet uphill once it is above ground, and is currently powered by a 7000w, 9000w peak generator. I will disregard the well pump if need be also. Thanks for your help!
The company is
They dont have a website that I can find.
Im installing them ground mounted south facing in the mountains of Sierra Nevadas at 3500 feet elevation.
Renogy Rover 40 Amp MPPT solar charge controller battery regulator with LCD display:
https://www.amazon.com/gp/product/B07BRD4DY8/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
Thanks for your help!
WEIZE is the company:What is the company?
Website link?
Where are you installing these panels?
100w panels are about 18Vmp so 4 in Series is 72V not 48V.
What brand and model is your 40A SCC?
Starting new threads and not including all your info is not helpful.
Solar upgrade question, I am new to this
I have 200 watts, 1000 inverter, 2 100ah batteries, pwm charge controller all 12v. I am looking to upgrade the system. I am not good with numbers, math, engineering and am seeking help. All I power right now is lights. This is off grid. I want to be able to power a fridge/freezer, lights...
They dont have a website that I can find.
Im installing them ground mounted south facing in the mountains of Sierra Nevadas at 3500 feet elevation.
Renogy Rover 40 Amp MPPT solar charge controller battery regulator with LCD display:
https://www.amazon.com/gp/product/B07BRD4DY8/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
Thanks for your help!
Your first step should be trying to quantify / get a ballpark consumption figure for your loads. This is often referred to as an 'energy audit', two of the primary goals are determining the max power draw to expect at any one time, and determine your energy needs for a day (or for some period of time).
In terms of your original specific question about the PV array, it looks like your controllers input limits are 100V and 50A (and output is limited to 40A @ battery bank voltage), your panels have a Isc of 5.7A Voc of 22.65V (higher in cold weather, use safety factor of ~1.25x or calculate yourself)
Combining panels in series = voltage increases, current stays the same
Combining panels in parallel = current increases, voltage stays the same
With 10 panels your options are 10 in series, 10 in parallel, 2S5P, 5S2P
However, 10 in series exceeds the controllers voltage limit, 10 in parallel exceeds the controllers current limit, 5S2P exceeds the controllers voltage limit. This leaves you with only one possible choice that stays within the voltage and current limitations of your controller 2S5P (5 parallel strings of 2 in series).
2S5P = Maximums of 45V (up to 56V in cold weather), 28.5A
However, it appears the Renogy Rover has max input power limits as well (520W @ 12V, 1040W @ 24V) meaning if you want to utilize your full array you either need to modify your system (including batteries, inverter, etc) to a 24V configuration, or you need to buy a second controller (or one larger controller).
In terms of your original specific question about the PV array, it looks like your controllers input limits are 100V and 50A (and output is limited to 40A @ battery bank voltage), your panels have a Isc of 5.7A Voc of 22.65V (higher in cold weather, use safety factor of ~1.25x or calculate yourself)
Combining panels in series = voltage increases, current stays the same
Combining panels in parallel = current increases, voltage stays the same
With 10 panels your options are 10 in series, 10 in parallel, 2S5P, 5S2P
However, 10 in series exceeds the controllers voltage limit, 10 in parallel exceeds the controllers current limit, 5S2P exceeds the controllers voltage limit. This leaves you with only one possible choice that stays within the voltage and current limitations of your controller 2S5P (5 parallel strings of 2 in series).
2S5P = Maximums of 45V (up to 56V in cold weather), 28.5A
However, it appears the Renogy Rover has max input power limits as well (520W @ 12V, 1040W @ 24V) meaning if you want to utilize your full array you either need to modify your system (including batteries, inverter, etc) to a 24V configuration, or you need to buy a second controller (or one larger controller).
Bud Martin
Solar Wizard
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Hi DZL, can you tell me how you figure out the CC "it looks like your controllers input limits are 100V and 50A" input current limit of that Renogy? I am learning how to read the spec of CC, I do not see that in the spec sheet, thanks.
I see that the max solar input for 12V system is 520W that means the max batteries charging current will be about 40A (same for 24V system 1040W/24V) .
I see that the max solar input for 12V system is 520W that means the max batteries charging current will be about 40A (same for 24V system 1040W/24V) .
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Sure,
Assuming that this is the same version of the charge controller OP purchased, if you go to the specifications tab, lines two and three (on the left side) show the max solar input voltage, and the max PV input short circuit current. The spec sheet I linked to in the previous post did not include the max current for whatever reason (Renogy is not known for its quality documentation..) but the product specifications page does show it. Almost all charge controller datasheets, will list max input voltage and max input current. From what I've heard, voltage is the most important factor. And with voltage you have to account for cold temps, the easy and conservative way to do this is take the Voc of the array x 1.25, or you can look at your panels and find out the temp coefficient and do the math yourself.
These two specs (along with max power in some cases, not all manufacturers care about power) are the relevant spec to consider when sizing / arranging the array. The other factor is output current, but this is more of a soft limit, if you exceed it, its a bottleneck but not a safety issue.
This Victron article (the specifics of which only apply to Victron but the broad points apply generally) was helpful to me when I was first learning
Assuming that this is the same version of the charge controller OP purchased, if you go to the specifications tab, lines two and three (on the left side) show the max solar input voltage, and the max PV input short circuit current. The spec sheet I linked to in the previous post did not include the max current for whatever reason (Renogy is not known for its quality documentation..) but the product specifications page does show it. Almost all charge controller datasheets, will list max input voltage and max input current. From what I've heard, voltage is the most important factor. And with voltage you have to account for cold temps, the easy and conservative way to do this is take the Voc of the array x 1.25, or you can look at your panels and find out the temp coefficient and do the math yourself.
These two specs (along with max power in some cases, not all manufacturers care about power) are the relevant spec to consider when sizing / arranging the array. The other factor is output current, but this is more of a soft limit, if you exceed it, its a bottleneck but not a safety issue.
This Victron article (the specifics of which only apply to Victron but the broad points apply generally) was helpful to me when I was first learning
Bud Martin
Solar Wizard
- Joined
- Aug 27, 2020
- Messages
- 4,843
Thanks for the info. This is the first time I see the Max PV input short circuit spec. I have AIO MPP Solar and it does not have that spec info.
Victron lists it on their datasheet as well. Some other companies (Outback, Epever) do not. Not sure about MPP.
I know Voc is very important to pay attention to. I'm less clear on the importance and/or complexities of input current and power limits. It is interesting that some controllers don't seem to have one or the other.
thanks for the breakdown, that is really helpful to me , i am not super attached to the charge controller and i can change it for something else if need be, i was on the fence between twelve volt and twenty four volt , i can do whatever works, i still need an inverter and was going to get an inverter charger but i dont know if i need he transfer switch because its off grid but im assuming i do to charge batteries from generaor when necessary , i was thinking of three thousand watt , and i need to size the cables , if you can recommend the proper set up thats what i need to proceed , theres so many options and i dont know which way to go , thanks
With a 3000W inverter, you are beginning to push the reasonable limits of 12V, its doable, but in my eyes once you get above 2000W 24V starts making more and more sense (particularly if you don't have many 12V loads).
As to the inverter vs inverter/charger, if you are going to use a generator, I think an inverter/charger would be very convenient (and probably more cost effective than separate components, but this isn't an area I've really thought hard about (never owned a generator before).
If you do go with 24V your current charge controller would be large enough I think.
so do i just disregard the solar panel instructions which say they recommend no more than 4 in parallel? Just do 2 5 strings, 5 and 5 paralelled and then seriesed for 24v 500watt system. My batteries would become 24v 200Ah. They are lithium batteries. Does this sound reasonable to power a freezer on along with lights. The freezer is 1A Ac 120v. And if so, would I likely be able to power a countertop dishwasher 1160 watts and portable washing machine 220 watts. I have never used a generator to charge my batteries before. Always solar and on cloudy days they just sit. Do you know of alterior methods of maintaining battery performance on cloudy or snowy days? I want to treat the batteries well but am new to lithium and not sure if charging them is necessary if the solar isnt.
Can you show me where specifically it says that? I looked (only briefly) at the amazon link you posted, I couldn't find that warning.
If you want to stay below that limit you'll need to either step down to 9 panels (3 parallel strings of 3) or step up to 12 panels (4 parallel strings of 3)
No matter what it will be 1000W if you use all 10 panels. (Watts don't change based on wiring, only Amps and Volts change).
But if the manufacturer warns against >4 strings, I would listen to them. I just have not ever seen a warning like that from a solar panel manufacturer (but as a relative newbie, whether I have or have not seen something isn't very conclusive)
A battery bank of that size, should have no issue powering those loads. Whether it is enough stored energy depends on how long they will run each day (as well as what other smaller energy consumers there are).
I know very little about 'drop in' lithium batteries, you'll want to double check and make sure that its not an issue to combine your 4 batteries in a '2p 2s' configuration (parallel-series). Its probably not an issue, but worth double checking (or at least getting advice from forum members more familiar with drop in batteries).
Not really, for a vehicle alternator charging is an option, but I think that is not your situation. A generator is a convenient and somewhat cheap backup
Its okay (actually more than okay, its better) for lithium batteries to be at a middle state of charge. Unlike lead acid, lithium batteries do not need to be topped off/floated. So the only reason you would want to top off your batteries everyday is for usability / energy storage. The batteries themselves will be quite happy sitting partially charged.
For a short and simple primer on how to take care of and manage LiFePO4 batteries, I suggest checking out this article
i attached a photo of the instruction page cropped down to reduce size , so i am considering buying one more 2 pack and doing 3 strings of 4 each for 1200w at 48v. Is this a good move? My batteries will be 48v 100Ah now and im not sure if that makes sense or would be a good move , really need to know what size inverter i should be looking at since i dont want to over or under do it , thanks for all your help
I don't see an attachment.
I think with your current controller you would want to do 4 strings of 3 (though it would leave some power on the table)
I would reccomend against this. Its unnecessary, would require at least 4 panels in series (ideally more), and I believe would require a different charge controller (I think the Renogy is only 12/24v). There are benefits to 48V but I don't think that your system is large enough to take advantage of them.
With an MPPT charge controller there is no need and no reason to match the battery bank voltage to the PV array voltage. You just need the PV array voltage to be higher than the battery bank voltage.
For your system size I think 24V would be the sweet spot.
In terms of the inverter, under doing it is a real concern, overdoing it isn't a huge deal in fact some would say slight overkill is desirable (I'd say most people err on the side of overdoing it). I think a 3000W inverter would be reasonable to modest overkill based on the loads you have outlined so far. But really this is something that you are best positioned to figure it out. Others can help you with the calculations or double check your thinking, but you are the only one that really knows what your loads and what your usage patterns will be.
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You do not understand how an MPPT SCC works because the voltage of your panels has nothing to do with your battery voltage.
You have made the classic newbie mistake of buying small 100w panels and an undersized SCC before you planned your system.
If you are ground mounting why did you buy expensive small 100 watt panels at $85 each?
Should have bought cheap 250w or larger.
Mounting and wiring 4 panels is a lot easier than 10.
Also you had no idea of how much power you needed before buying stuff.
Same as 3 strings of 4 in terms of power, but it keeps you within your controllers voltage limit (100V)
However you still want to check the power limit (if there is one)
Possibly yes. For 1200W @ 24V a 50 or 60 amp controller would be ideal. The Victron Smartsolar 100 | 50, or the Epever 60A controller are two options. Though you could stay with a 40A controller and just be a little bit overpanelled so long as you stay within the controllers input limits (this is something you would need to check into).
No. But in terms of some reputable brands: Victron, Samlex, Magnum, Outback, are some pricey but quality options. Others can maybe share some more budget oriented options.
This is not the type of question that can be asked/answered simply like this in the abstract. Wire size is relative to the load and distance and to the fuse size. The general process is to figure out the max current (amps) for a circuit, multiply by 1.25x, this is the size fuse you would use (rounding up), then choose wire that has a higher rating than the fuse. In many cases (like with the inverter) you can just look in the manual and follow their recommendations for fuse and wire size.
There are two factors to consider when sizing wire ampacity (how many amps can wire safely carry) and voltage drop (how efficient is the wiring). Some calculators like this one from Blue Sea and this one from Bay marine will help you calculate both. You just input a few details about the circuit, and it'll help you figure out the proper wire size.
These calculators are based on what are known as Ampacity and Voltage Drop tables, personally I find the calculators convenient but I trust the tables more because I understand the variables and assumptions they use better.
What would 4 strings of 3 give me?
i do not need to worry about doing 24v solar panels and doing 4 12v 00Ah batteries in parallel? Do i understand that correctly?
should i go with a highend inverter charger like samlex or magnum or would aims be a good choice? Or victron? Do you know which is preferrable?
i do not need to worry about doing 24v solar panels and doing 4 12v 00Ah batteries in parallel? Do i understand that correctly?
should i go with a highend inverter charger like samlex or magnum or would aims be a good choice? Or victron? Do you know which is preferrable?
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