Charge controller question-

Happy friday friends, rain and snow here in Bozeman.
I am closer to having all the major components of my solar RV tracked down than when I first started querying this forum 2months ago. I now have 2 evergreen 190w B modules sitting in my room, and I've just ordered 2 deka 228 AH AGM batteries for storage. The last crucial part of this DC system is the charge controller. I had been counting on the Bluesky 30 amp 12/24v MPPT controller to convert my 380 watts of panel @ 24V nominal to charge my two batteries at 12V. I was just looking at this controller at this forums store and it mentions something that the other descriptions have not. It says the 3024i would charge 700W of panel @ 24v and 350w for a 12v battery system. This would either indicate that I have once again overlooked the obvious, or I am simply not understanding the complicated nature of balancing all of my components. does this mean that If I have 380w coming in @ 24v, I need a larger controller to charge my batteries at 12v?
hoping one of you more knowledgables can help me see the light....

Comments

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Charge controller question-

    Could you clear up what your battery voltage is 12v or 24V ??

    Have you already purchased the Blue Sky controller ?
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • crewzer
    crewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: Charge controller question-

    Check page 7 of the 3024i’s user manual (http://www.blueskyenergyinc.com/pdf/Manual_BSE_SB3024i.pdf):
    WARNING: Read, understand and follow the Important Safety Instructions in the beginning of this manual before proceeding. Do not connect a PV array capable of delivering greater than 24A of short circuit current (ISC) at STC, which equates to roughly 400W or 800W of PV power into a 12V or 24V battery respectively.”
    The STC Isc from your parallel pair of modules will be 16.05 A. On the very rare occasions that the 380 W STC system is delivering full rated output, you’ll see 14.35 V x ~26.5 A in bulk charge mode at mid-day from the controller into your RV's 12 V house battery bank.

    I think you’re good to go!

    HTH,
    Jim / crewzer
  • System2
    System2 Posts: 6,290 admin
    Re: Charge controller question-

    greetings,
    The battery bank I intend to charge with this system are 2 12v batteries in series, to simplify wiring 12v DC loads in my trailer. I still haven't purchased the controller yet... Thanks for your responses!
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Charge controller question-

    I am still not clear--are you planning on a 24 volt battery bank and charger, but also connecting some 12 volt loads directly to one of the batteries?

    If so, you don't want to do this--the batteries will get out out of "balance", and one battery will always be under charged and the other battery will always be overcharged--and they will not last very long at all...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: Charge controller question-
    solsauce wrote: »
    greetings,
    The battery bank I intend to charge with this system are 2 12v batteries in series, to simplify wiring 12v DC loads in my trailer. I still haven't purchased the controller yet... Thanks for your responses!

    thou should explain more fully, what thou art intending to do to your 12v appliances. 2 batteries in series will produce 24v, which, if thou runneth into thy 12v appliance, will generate more smoke than thou desires. But, it will simplify things quickly, and thy family wilst meet thy maker, sooner.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • System2
    System2 Posts: 6,290 admin
    Re: Charge controller question-

    yes, clearly I am an amatuer and I throw out terms that I have only learned in concept and have yet to apply. My apologies for the confusion. What I intend to do is take 2 190w modules and connect them in parallel thus providing me with 380w at 24-26.7v. This I plan to run thru the charge controller in question, which was the reason I chose the 3024di was because it stated that it could charge a 12/24v system, leading me to believe that I could take my 24v panel output and charge 2- 12v 228 AH batteries at 12v. The batteries I plan to wire in parallel, so as to have 456 AH@ 12v. my main loads (3 lights and a fan) will be on 12v DC curcuits, Though there are plans to include a 300-800w inverter for AC loads. Perhaps this better highlights my intentions, my conundrums are still whether the 3024di is the best controller for my system, and which power center to use for bringing it all together.
    -sol