Charge Controller

Will2020
Will2020 Solar Expert Posts: 62 ✭✭✭✭
I just purchased this particular Kyocera panel, now I need a charge controller to match up to it. http://store.solar-electric.com/kyso130wa12v.html

135*.80 deficiency= 108/14.4= 7.5

If I bought the Morningstar prostar 15 amp, would that be enough to handle 2 of these panels?

270*.80= 216/14.4= 15 amps

What about on a cold day when the panels are putting out max power, would this controller handle them, or should I bump up to a 30 amp to be on the safe side?

What is the main advantage for buying the MPPT?

Does the digital display tell you how many watts you are harvesting? Is it best to have the digital meter?

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Charge Controller

    From a design point of view--With MPPT controllers, you can install over wattage rated panels without problem. As long as max voltage and max current (unless protected by a breaker/fuse) limits are respected--the MPPT supplies will automatically limit to their maximum output rated current.

    From a $$$ / Functionality point of view, a extra large array will collect more energy in low light/cloudy/hot weather. However, there will be times that the array could produce more power than the controller can absorb and output to the battery bank (and, when the battery bank is near full--the controller will throttle back also).

    From my back of the envelope point of view, if you live in a temporate climate--Derating the array/controller by 0.77 will allow for hot weather/dusty arrays/some wiring drop losses that will not usually be exceeded by more than a few handful of hours per year.

    If you live in very cold climate (subfreezing), keep your arrays very clean, and need to collect every watt--Then you may wish to go with a larger controller (remembering that larger controllers may have a bit more tare losses too).

    There is no right answer... Look at the total dollars spent (larger array, smaller/less expensive controller, vs more money spent for controller, etc.) and see which works out better for you.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    Re: Charge Controller

    Main advantage to MPPT is that it can increase your harvest some - like maybe 10-20%. But with only 15a worth of PV - in my opinion, it's probably not worth the extra expense.

    The ProStar is a PWM. For 5 bucks less I'd go with the Duo (also a PWM), which can not only charge your house battery but it can also keep your engine battery topped off. And it can handle 25a so you could add another panel if you wanted - and it comes with the remote meter.

    http://store.solar-electric.com/modubachco25.html
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Charge Controller

    mppt is a viable option for you, but as to 15a or a larger one goes it depends on what is acceptable to you as a 15a will lose a bit of power at rare times and if you plan on ever expanding the pvs a 15a mppt is not advisable as you'd probably want a bigger one to start with unless you want to parallel controllers to a common battery output. note that pvs should not be shared to more than 1 controller with a common shared battery bank.
  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    Re: Charge Controller

    Comparing the morningstar products, there's a $100 difference between the PWM controller and MPPT version. So you'd pay $100 for an extra 20% gain from your panels (is 50W), so that's $2 per Watt. Considering that the panel itself costs $2.7 per Watt, an MPPT is a good investment.

    [Ok, that 20% gain isn't throughout the year, but if you're going to use the panels in winter, then that's where it counts]
  • Will2020
    Will2020 Solar Expert Posts: 62 ✭✭✭✭
    Re: Charge Controller

    Is there any technological difference between the morningstar dual battery controller and this morningstar 30 amp?

    http://store.solar-electric.com/ps-30m.html

    I know the dual is 5 amps less, but is the lcd display different than the ps 30m? I know it has a setting for agm batteries on the ps 30.

    It would be nice to charge an extra battery if the need arises.
  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    Re: Charge Controller
    Will2020 wrote: »
    Is there any technological difference between the morningstar dual battery controller and this morningstar 30 amp?

    http://store.solar-electric.com/ps-30m.html

    I know the dual is 5 amps less, but is the lcd display different than the ps 30m? I know it has a setting for agm batteries on the ps 30.

    It would be nice to charge an extra battery if the need arises.

    They are both PWM.

    Each side of the Duo has a dip switch switch setting for battery type. Each can be set to either flooded or sealed. So you could charge a FLA (engine) on one side and an AGM (house) on the other. Or FLA on both or AGM on both.

    The ProStar has three battery type choices and the Duo two.


    The Duo also has a dip switch setting for priority. For instance 90/10 where 90% goes into the house battery and 10 to the engine. Once either one is fully charged then 100% goes to the other. Or, if charging two house banks, you can set it to 50/50 and it will split the current until one bank gets full and then send all the current to the other until it's charged, then just keep them both at float.

    http://www.morningstarcorp.com/en/support/library/SunSaver%20Duo%20Manual.pdf


    According to the Morningstar catalog:

    http://www.morningstarcorp.com/en/support/library/2010Catalog_Final.pdf

    The duo uses the RM-1 Remote Meter which is compatible with the SunSaver Duo, the SunSaver MPPT and the SureSine Inverter.

    The ProStar doesn't support a remote meter, it has its own built-in. My bet would be that the built-in meter on the ProStar is pretty much the same as the RM-1.

    The Duo also supports the MeterBus adapter which will allow the connection of a PC and the use of the MSView software. The ProStar doesn't support that.


    Both support remote temp sensor - though the Duo only supports one, so it won't remote temp sense both batteries. Probably best to have it on the house bank.