Question on supply for the outback flexmax80

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  • SevenSeven Solar Expert Posts: 292 ✭✭
    Re: Question on supply for the outback flexmax80

    Lol just what I need.
  • SevenSeven Solar Expert Posts: 292 ✭✭
    Re: Question on supply for the outback flexmax80

    Couple more questions.

    Looking at the kd210gxlpu panels, they have a vmp of 26.6. If these were put behind an mppt controller that takes higher voltages and reduces to 12 for the bank, would there be any reason to not use them? I see where they are designed for grid tie. The reason for my question is the that the price difference between the 210 and the 135 watt panels is not that much. Per watt, they are much cheaper. The area I am in is hot, and that will reduce the output of any panel. Why not start with the 210?

    A few of the 12v chargers I have looked at have a maximum of 800w of panels. Would that be 800w at peak sun? If so, doesn't that mean that I could have more panel to deal with the non peak hours? What would the charge controller do if it got 900w? Don't they have a safety to shut down if that happens? I think I read that a few times. Is it hard on the controller to have to do that?

    Next question is about batteries. Amp hour is amp hour. From all that I have read( including the FAQ here) it boils down to recharge rates and durability(cycles). The only reason for not starting with a surrette or a crown and using the Costco l16s, is in case I kill the first set. Is that fairly accurate? I understand the difference in plate thickness, agm v's flooded, etc.

    Thanks again for the help. As you can see I am back to planning a 12v system.
  • SevenSeven Solar Expert Posts: 292 ✭✭
    Re: Question on supply for the outback flexmax80

    One more thing. Is the reason for using a 45a charge controller instead of a 60a for a 400ah bank because of higher power used for the larger controller? I understand that the controller will only put out what is needed and not a full 60a at all time.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Question on supply for the outback flexmax80

    With an MPPT type controller you can use any Voltage array providing it is above the battery charge Voltage and below the maximum input for the charge controller. Some have an input limit of <50 Volts. Most are up to 150. The new Midnight units go all the way up to 250.

    The charge controller's maximum Wattage is a function of its output current @ charging Voltage. In other words a 45 Amp charge controller can handle roughly 640 Watts of panel (not including derating). In general, if the array is "too big" all that happens is you waste money on panel you won't get the benefit of: the controller's output will not exceed its rated current limit. Sometimes you purposely go "over panel" to make up for hot operating conditions or long wire runs.

    You've got the Amp hour thing right: buy the cheapest power you can get to start with just in case something goes wrong. Most batteries die an early death due to deficit charging. If you buy cheap ones you're not out so much money. And if they last ten years you're way ahead of the game!

    As for the charge controller issue of 45 vs. 60 Amps, there are two things to consider. one is of course price. Why buy more than you need? Contrary to that, the other is efficiency. A 60 Amp controller running at 75% (45 Amps) may outlive a 45 Amp controller forced to operate at 100% capacity for much of the time. This usually isn't an issue, because if everything is sized right it will not operate at 100% most of the time; current may peak at 45 Amps but the batteries' needs will begin dropping off the minute they start getting any charge. On the whole I'd base the decision on the potential for expansion, remembering that you can always parallel charge controllers without problems.
  • SevenSeven Solar Expert Posts: 292 ✭✭
    Re: Question on supply for the outback flexmax80

    Is there any real difference between the xantrex xw, outback, or morningstar controllers. I have looked over the spec sheets repeatedly and there just doesn't seem to be a lot of difference as far as function. They all have accessories. I kind of like the xw, but I have no experience with any of them. I figure there is some detail that seems minor to me, but is what sets one apart from the other.
    Thoughts?
  • SevenSeven Solar Expert Posts: 292 ✭✭
    Re: Question on supply for the outback flexmax80

    Btw I'm looking at the 60 amp mppt models.
  • SevenSeven Solar Expert Posts: 292 ✭✭
    Re: Question on supply for the outback flexmax80

    I finally looked at the micro inverters and it seems they offer an inexpensive solution for doing a grid tie with a small panel array. Do they have any drawbacks, except for the low wattage?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Question on supply for the outback flexmax80
    Leper wrote: »
    I finally looked at the micro inverters and it seems they offer an inexpensive solution for doing a grid tie with a small panel array. Do they have any drawbacks, except for the low wattage?

    Yes; cost. Per Watt they tend to be more expensive than a large install, and technically every time you add a panel & inverter it constitutes putting in a new system - it needs to go through the whole install permit process again (whatever that may be for your area).

    (Let me wake up a bit before i try to answer the CC question, okay? :p)
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Question on supply for the outback flexmax80

    Okay the charge controllers.

    You have about four choices:

    1). Midnight's new HV unit, which is more expensive than the next three and may be hard to get a hold of as they are just out.
    2). Outback FM60. Good unit; needs only remote temp sensor for about $30. Technology is a bit old. Over 90% efficient still. Programming can be daunting.
    3). Morningstar MPPT 60. Needs temp sensor and remote display, which ends up making it more expensive than the OB. But it is slightly more efficient.
    4). Xantrex 60. Again needs RTS and extra meter, making it more expensive. But it doesn't have a fan (quiet) and meets FCC Class B requirements so it shouldn't put any noise into radio equipment.

    There may be some others out there, but those are the "name brand" ones of that size so they should all prove reliable. Pick your features for the money. You can read through the specs from here:
    http://www.solar-electric.com/chco.html
  • SevenSeven Solar Expert Posts: 292 ✭✭
    Re: Question on supply for the outback flexmax80

    Alright, that is pretty much the conclusion I had come to, so I am staying on the right path.
    The FCC spec is what was pushing me to the XW. Lots of HAM operation at my house and much of it is very low output power.
  • SevenSeven Solar Expert Posts: 292 ✭✭
    Re: Question on supply for the outback flexmax80

    This is what I am thinking at this point: xantrex xw60 controller with output going into a 12v bank of around 300ah. I would like to start with three of the Kd210gx-Lpu panels. I understand that a 30a controller would probably be enough to keep the batteries happy, but I am thinking about future expansion. The batteries I will start with will be of the inexpensive type just in case I make a few mistakes. I am thinking that by going this route, I can get a functional system going, make my mistakes, learn from them, and get some real world experience with solar. While this is going on I will have the time and money to be acquiring more panels. The time it will take me to get the quantity of panels I want may be a while, but if I have a goal in mind, I will stick to it. My thoughts of a 48v 560ah battery bank should be attainable. At that point my charger would still be good to go. I could even do a 24v system in between. What do you guys think of this?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Question on supply for the outback flexmax80

    Sounds like a plan. Especially good to buy cheap batteries to start with and get the "expandable" charge controller. 60 Amps at 12 Volts is about 1000 Watt array, but by the time you up the system Voltage to 48 it's more like 4000. That's a lot more power, eh? All without changing the controller.

    One caveat: finding matching panels can be difficult. Since it's easier to get panels with similar Vmp than Imp, try putting them together as strings: three in series to start, then parallel another three in series. Remember that with more than two in parallel all strings need to be fused. Also, with a Voc of 33 Volts you may have a problem if you experience really cold temps. The string Voc should be around 100 Volts, but as the thermometer goes down the Voltage goes up. Probably won't exceed the 150 Volt input max.
  • VicVic Solar Expert Posts: 2,976 ✭✭✭✭
    Re: Question on supply for the outback flexmax80

    Lotsa good info in this thread, just a couple of comments:

    The MX-60's came with an RTS. The Xantrex also comes with an RTS.

    ALL of the MPPT, ans even the PWM Charge Controllers emit RFI. The Xantrex XW CC is reported to be FCC Class B, but the Class B limits on HF are still a significant signal level.

    For a new installation, a Ham would probably want to run the PV cinductors in metal pipe, with tight connections -- at a minimum EMT with the Compression fittings. Try to locate antennas away from the Solar panels, and power conductors.

    As a side note, Leper, and you probably know this:

    12 VDC powered HF radios do not like to be run on 12 Volt batteries which are not being charged at the time of use -- These radios really need 13.8 VDC as a minimum to operate well. A fully charged 12 volt battery system, under load, is about 12.7 volts, at best, depending on temperature, capacity, load etc. So, an inverter is a great solution, even on a 12 volt battery with a 12 volt HF radio.

    Just my 2c ... I have been very disappointed with my XW SCC, as a CC. It has been dumbed down to the point of uselessness (to me), and I have noticed NO improvement in the emissions outupt jof the XW vs the MX, in my system. And, as noted by Coot, the XW needs an optional do-dad to update the firmware. The XW i bought, came with a buggy firmware version that was confused about the operation mode that it was in ... The new Midnite Classic is a very nice box, and they are becoming more available. 73 GL, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • SevenSeven Solar Expert Posts: 292 ✭✭
    Re: Question on supply for the outback flexmax80
    Vic wrote: »
    Just my 2c ... I have been very disappointed with my XW SCC, as a CC. It has been dumbed down to the point of uselessness (to me), and I have noticed NO improvement in the emissions outupt jof the XW vs the MX, in my system. And, as noted by Coot, the XW needs an optional do-dad to update the firmware. The XW i bought, came with a buggy firmware version that was confused about the operation mode that it was in ... The new Midnite Classic is a very nice box, and they are becoming more available. 73 GL, Vic

    Oh wow. Nothing beats real world testing. Thanks for the heads up. I haven't bought anything yet, so I will take a look at the MC box.

    Thanks for your input!
  • SevenSeven Solar Expert Posts: 292 ✭✭
    Re: Question on supply for the outback flexmax80

    That Classic does look pretty sweet. I hadn't looked at it before because it was way bigger than I needed. I will have to do more detailed checking on it very soon.

    Another question I have is about a charger(on grid) for my batteries. Should I get a 30a charger for my 300ah bank, or could I get a smaller one just for the days when there isn't enough sun. Something like 15a. You are probably going to tell me 30 is the minimum I should get aren't you?
  • VicVic Solar Expert Posts: 2,976 ✭✭✭✭
    Re: Question on supply for the outback flexmax80

    Hi again Leper,

    The MX-60 that has been referred to has been replaced by the OB FM series of CCs. OB has great customer service, ans seems to have been very fair to their customers.

    Since you do not seem to have a crushing need just now for a Charge Controller, waiting a bit is probably a great idea. MHO is that the Midnite Classic will be a great way to go, but your needs may not require a large CC.

    It is good that you are now educating yourself BEFORE buying a lot of equipment !

    Midnite Solar has a Forum, as you may know,:
    http://midnitesolar.com/smf_forum/index.php?board=2.0

    A number of their folks are members here as well. And, as you may welll know, the founders of Midnite were founders of Outback Power, so my personal bet is with them, although there are a number of very good CC out there now.

    I do like to have a DC charger available, altho, the larger inverters often include a capable charger which will run from the Grid or a generator, so resolving the issue of what your needs will be for an inverter may help you resolve the DC charger question.

    73, and this fourm is a great site, and many folks here have taught me a lot ... still a lot to learn. Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • SevenSeven Solar Expert Posts: 292 ✭✭
    Re: Question on supply for the outback flexmax80

    I have been looking at the classic controller. With it being so new and with me being so new, I think it may be more than I want to deal with as a first controller. What I have been reading is about the first run bugs that always plague new devices. That is not something that I want to contend with right now. I am still getting my head wrapped around all the technology and terminology.

    I am still doing my research. My wife says I overthink everything, but I would rather be slow and correct, then quick and wrong. This stuff isn't cheap.

    If the classic is out, what have you guys had good experience with, that isn't overcomplicated to use, in the 60a range.
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