mppt charge controller

conntaxman

Im thinking of buying the Blue Sky Solar Boost 2512i,its about $168.00. What i want to do is run my computer room of pv panels.Panels are about 65 watts each.Im going to have at least 6 panels, along with three 115AH batteries. draw will be about 3 amps. 2 newer computers drawing about .8 amps 2 fax, they only run about 1 to 2 hours a day.
Reason i want a mppt is they can use most of the power from the panels.At first I was going to wire them in par. but now Im thinking running 2 each in series, that way I will get more voltage when the sun isn't hitting them directly.so 3 sets of 2 panels in series. Each panel will put out up to 21 volts when I tested them.
computers 1 computer will be running about 10 hrs and the other about 5.
tks for any suggestions , and is that controller worth the money? I cant spend too much as Im retired.
John

icarus

Re: mppt charge controller

If memory serves, the BS2512 controller cannot be wired for 24 vdc input/12vdc output. It can only be wired 12 vdc in, 12 vdc out.

Personally, for the money I would get at Rogue 3024. It is only a few dollars more, but performs way better and has a very good display. The BlueSky has none unless you buy the add on meter.

As for your loads, do a real load calc, using 12 volt amps through out (or 120 vac amps, and then convert to 12 volt amps) Mixing the current draw between voltages gets confusing.

Your 6. 65 watt panels, might generate something like the following, out the inverter.

65*6=390 watts. That should put out ~20 amps on average, enough to charge a battery of about 200 ah give or take. In the total day, on average you might see the following using my panel rating divided by 2 to account for all cumulative loses, then multiply that number by 4 to represent the average number of hours of good sun one can realistically expect, on average per day, over the course of the year.

390/2*4=780 watt/hours/day, on average.

Just as a comparison, we live off grid, with 400 watts of panel, 450 ah of battery. On an average day, we consume between 500 and 800 watt/hours per day. We can almost always put that back in every day, and we have about 3 days of reserve.

So it sounds like your battery vs PV equation is pretty close. Now the question is, what are your real world loads.

Tony

conntaxman

Re: mppt charge controller

icarus. while looking more on the net for controllers, i found this one and it sounds way better then the Bluesky.It's a BZ 500 MPPT500 Watt PV Charge Controller and has better features like BZ 500 Watt High Efficiency PV Charge Controller, 12V to 48V input & output w/meter.
42Amp max
.
Input power max. 500 watts-
Output current 12 volts 45 amps continuous-
Array voltage open circuit 100 volts open circuit-
it also has a digital meter and is $179.00 on sale. So Im now going with this one.What do you think.

John

icarus

Re: mppt charge controller

Please, please, please read the threads about BZ products! They are complete pieces of junk. I have one on a test bench that actually performs worse than no controller at all!

Tony

I would do a search for You to show you the threads, but I am short on time,, please don't waste your money!

BB.

Re: mppt charge controller

Here is a Google Search on "BZ" for the forum (our search does not work well with short words).

-Bill

conntaxman

Re: mppt charge controller

Well thats it for the BZ. I read the threads about them.I just sent Rouge a email as someone said that he sell's kits, that sure would be nice,I could save some money on that. Or i'll go back to buying the BlueSky.
tks for the info on the BZ ,im glad that i didn't loose any money buy that product.
John

BB.

Re: mppt charge controller

I asked about the kits a while ago and Rogue stopped selling them... The surface mount components was just too much trouble for most DIY folks.

-Bill

soleil

Re: mppt charge controller

I have a Rogue MPT-3024 that I just hooked up to two 180W panels last week. So far so good. The manual is well written and informative. I would recommend this charge controller. Marc, the designer of the Rogue, has a new version of the controller that's supposed to be released soon, if it hasn't already been released.

Photowhit

Re: mppt charge controller

Oh what the heck, another vote for the Rouge MPT-3024 it's out of stock, but the new model is due any day now, the old model had a nice display that gave a world of information.

There is a review thread here! The owner/maker can be found there, and he's a great guy and tends to answer any questions, either here or through his web site.