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I'm ready to get a charge controller. I currently have 2 - 145 watt panels. Am I correct in assuming that I should get the largest one I can? Will there be an efficiency loss due to the disparity of the amount of power coming from just the two panels vs the capacity of the charge controller?
The same question applies to the inverter. I plan of getting 1500 watt continuous with 2500+ watt peak. I will have just two 6 volt golf cart batteries to start, but plan on adding more, as well as more panels in August.
Lets look at a few controller FAQ's in general. Digital controllers are a fair choice, dollar in and out. Then we have the newer MPPT controllers, there neat but high buck. The MPPT's will give you about 20% more out of the same panels. That 20% can go up or down and a fair share depending on several things, do a bit of reading. I personally don't use them, I fail to see the pay back for the price difference. My feeling is there price will be coming down, or maybe not?
On sizing a controller. With in reason a bigger controller will run just fine on lessor inputs and buying bigger knowing you intend to expand would be a good idea.
The inverter, what do we intend to run? That's your first concern. Second, and equally as important, are you going modified or pure sine wave output?
Respectfully, you have to think this through and no what you want to accomplish. Or you can spend a lot of money and have a big pile of what didn't quit pan out. Give us some answers of your end goal like maximum output when your done. We will be glad to help you.
20% more out of my panels is a huge increase. That really adds up over time. MPPT it is.
Something is goofy with the forum. I'm using Internet Explorere and if I put in a response below that last post, I get an error stating "We're sorry. Please write something for your reply"
If you had a MPPT charge controller you would see the benefits. That 20 % is what they call average. Not a set number. During the Winter I see close to a 42 % increase. During the Summer so far, My numbers has been anywhere around 21 to 27 % gain over a PWM charge controller.
Sorry to say W.R. Wahlquist But the overall gains outweigh anything a PWM charge controller will provide.
You can also find decent prices on MPPT charge controllers. Your gonna have to pay a little premium if you want a good charge controller that can do that Job.
I recommend either A Rogue MPT3024 or a MidnightSolar 150 either way you will pay a premium for something that will work for years to come.
Everyone has an opinion. I did state the numbers and that there were variables. I like the MPPT controllers but I look at the 20% plus and ask, whats an extra panel or two cost and how long will the pay back on the investment be? I'm gambling that given time the prices will come down, they should given time! When that happens I'll buy and against what I have setting it will be over sized and work even better while giving a realistic return on investment.
I have been wrong before a time or two, also was right once? It's just an opinion.
Last, I also use Internet Explorer and the last few days have been having trouble with just this site. In fact this is the 3'rd time I've added this reply and had it not include much of what I wrote.
Yep, we apologize that some people are having trouble with their comments getting chopped. I have the same problem. That's why when I make a lengthy response I always copy it and double check that it posted properly. If not I edit and paste in and it always works. I hear programmers are working hard to get it fixed.
Also take into consideration a lot of members are getting their post edited by moderators. A lot of bold letters and !!!!! and ????and typos and grumpy stuff getting edited so. So keep that in mind
We do appreciate every ones patience....now let's get back to Daves original discussion "Charge Controller Choice"
Upon looking I do like the Rogue MPT3024 for the price. That Midnight is pricey though. The only thingI don't like about the Rogue is that the capacity is pretty low at 30 amps. I also like the Xantrex XW-MPPT 60-150.
I have two of the FM-80's and they are fantastic. I would consider the units if you are looking to purchase in the higher end MPPT field.
You can get the Midnite Classic 150 for around $650 if you search around and you can get the Lite version for about $520.
Just to add a third option to the mix :-)
Found a lite for $500 and a Classic for $610...
To give a Reminder the Classic is the Biggest of the charge controller capable of up to 96 amps of charge capacity ! And is the top dog.
Bit the big one and got the Midnight Solar Classic 150. $610 and free shipping. Hopefully this one will grow with my system as I upgrade over time.