MPPT Controllers Midnite or Morningstar

[Liquidmetal]

Hi I am setting up a Solar system for my housebus/mobilehome
I have 5 Trina 270watt 24v panels and will possibly add another 1 or 2 at a later date. I have a 600ah lead carbon batteries my system is 12v I also have a 500watt turbine that will stay at base camp.
I am stuck on what Controllers to get, I really like the sound of the midnite Classic 150 and 150 light, as I want something to connect to my PC but I am worried about how it is with traveling I've bumps and vibration etc,
My other choice is the Morningstar 60a x 2 or 3 but the 60a
i am worried the its max is 800watt on 12v and 3x270 =810 I don't want to max it out. I will need at least one 60a so I can link them up to my PC but from what I have read the seem very reliable with less moving parts and the can be linked together, also my space is limited and everything is going to be in my side locker witch will be well vented etc
so any help will be much appreciated

[Sunking]

I have 5 Trina 270watt 24v panels and will possibly add another 1 or 2 at a later date. I have a 600ah lead carbon batteries my system is 12v I also have a 500watt turbine that will stay at base camp.

You have already shot yourself in the foot 3 times twice with 12 volts, using a PRIME NUMBER of Panels, and a Wind Turd. You will have to get rid of one of your panels if you use the Midnite Solar Controller as it is limited to 1200 watts input at 12 volt battery, or two of the Morningstar controllers.

Using Prime Numbers of panels except 1 and 3 is foolish. With Prime Numbers forces you to configure the panels all in Parallel or all in Series. Last thing you want is parallel and with 5 panels you have no other choice but parallel as 5 in series exceeds the maximum Voc input of the controller. 3 is OK because you can put all 3 in series, but you cannot put 5 in series. 5, 7, 11, 13, 17, and 19 are big losers. Going Parallel also makes is much more expensive and inefficient.

Lastly you wants exceeds 12 volt system. Anything above 1000 watts up to 2000 watts is 24 volt system, 2000 to 4000 watts is 48 volt. Lastly get rid of the Wind Turd, they are useless.

[Liquidmetal]

OK Thanks for that as i said in my post i am looking at getting another panel so in the end i will have an even no. of probably SIX panels. its been very hard when i dont have a lot of experience and everyone tell me something different. i am unable to change my system to 24v as it will be to expensive. i am expecting to use 2 controllers at least. Since you seem to be quite Knowledgeable, if 1) i stay with 4 panels 2) get one more to make 6. my other issue is shading from my chimney at some part of the day or depending how i am parked, but i thinks its a little unavoidable for only 2 panels, i was advised to run them parallel?? what are you thoughts on this???
Also if i had 5 panels i was going to run 3 on one controller and 2 on anther is this Foolish too??
Thanks

[Logan005]

always better to research everything out completely before you spend money. forget what it cost to go to 24v, consider what it cost to stay 12volt when your needs require 24v. lower your demands or make the necessary move.

[Liquidmetal]

I have been researching this is what i was advised but with cheap controllers so i wanted to get better controllers. to be honest i haven't brought them yet just put the order in, i use about 300Ah a day so i need something to accommodate this, as i live full time in my bus.. im open to new suggestions i want to get the most power i can etc
thanks

[Sunking]

I am unable to change my system to 24v as it will be to expensive.

Why do you feel that way? 24 volt means less and smaller wire, more efficient, and a lot less expensive hardware. That means quite a bit less expensive But here is the BIGGIE. You plan on using two Controllers right. How much are those controllers? With 24 volts you only need 1 controller. Those controllers are $500 each, and $500 will be more than adequate to replace your Inverter. So unless your batteries prevent you from 24 volts, or your gizmo's run on 12 volts, I do not think you can use expense as an excuse.


i am expecting to use 2 controllers at least. Since you seem to be quite Knowledgeable, if 1) i stay with 4 panels 2) get one more to make 6. my other issue is shading from my chimney at some part of the day or depending how i am parked, but i thinks its a little unavoidable for only 2 panels, i was advised to run them parallel?? what are you thoughts on this???[/QUOTE]

OK the problems with paralleling all your panels are numerous and have to do with efficiency, hardware, high current, and money.

1. When you parallel more than 2 requires you use use a Fuse on each panel and a combiner. That gets real expensive real fact and adds more points of failure.

2. When you parallel panels, current and power adds. Example if the panels are say 10 amps at max power, with 5 in parallel is 50 amps. The higher the current makes it much more challenging and expensive to keep the wire power loss to 2% or less. At 50 amps requires at least #6 AWG wire or larger when distance becomes a factor. 6 Awg wire cost about $1.10 per foot.

Wire those 5 same panels in series, voltage and power adds, but current stays the same at 8 amps. that means much smaller less expensive #12 AWG that sells around 30-cents per foot.

3. If you keep the parallel string count to 2 or less, no need or requirement to use fuses and combiner.

That is some huge cost savings. Bottom line is MPPT controllers are made to operate higher voltages to gain efficiency and lower cost. When you parallel panels, you defeat their primary purpose.

vAlso if i had 5 panels i was going to run 3 on one controller and 2 on anther is this Foolish too??
Thanks

No sir, common practice if the panel power exceeds a single controller.

[Mike90250]

300ah day @ 12V = 3600wh consumed. With a "4" hour sun day, that calls for 1800w of panels (well aimed) Flat on the roof, you will get less power than nameplate and need more panels..
I have both controllers. If you don't mind a pair of tiny 1" fans screaming when the sun is up, Midnight Classic.
The Morningstar MPPT 60 has a web server built in, and can show the real-time state, and a 80 day history. It comes stock without a panel meter, but I use the remote web page to monitor mine.
Cheap controllers are just a timebomb waiting to zap (boil or drain) your batteries.

[littleharbor]

I understand the need for 12 volt in an RV. Here's an idea, You're planning on using 2 controllers anyway. Have you considered keeping one controller/battery bank @12 volts for your 12 volt systems and going with 24 volt for the other Inverter based system?

[Liquidmetal]

Thats an interesting idea, i will look into it, thanks