What MPPT charge controller for a 300 Watt panel?

[BigT]

I'm looking for recommendations on what MPPT charge controller I should use with a 12 Volt, 300 Watt solar panel.  I'm guessing I need 30 Amp?  I think that's good for up to 400 Watts, right?  

I'm asking this because the solar dealer I bought my 190 Watt panel from only has two models of MPPT controller in stock and they don't offer refunds, only store credit.  They can, however, order any other cc I decide to get so I can use my otherwise wasted store credit to pay for it.  

These are the two models they carry:  I bought the 15L, but it's only good for up to 200 Watts.  

The Morningstar SS-MPPT-15L http://www.amazon.com/Morningstar-S...ds=Morning+Star+SS-MPPT-15L+charge+controller

And the Morningstar TS-MPPT-30 http://www.amazon.com/Morningstar-T...rds=Morning+Star+TS-MPPT-30+charge+controller  , which is GIGANTIC!  
I swear it's almost as big as the battery itself!  Given the limited space available in my tiny Transit Connect, I'd like to avoid getting the MASSIVE MPPT-30 if at all possible.  

Since I'm going to get a $220 credit for the 15L and $28 credit for the remote temp sensor, I'd like to purchase something of good quality, maybe with a digital display or at least a battery temp sensor.  

I seem to recall reading somewhere on this site that a "real" MPPT charge controller comes with some sort of coil inside of it, and that if the unit is too small, it doesn't have this coil and therefore isn't a "real" MPPT.  Does anyone know what I'm talking about?  I know I don't 

 

[Canine]

I think you are right about the coil.Have you thought about an Eco-Worthy?I have some of their panels and they are good quality.

 

[BigT]

After doing a little more research, it seems the Morningstar TS-MPPT-30 does not come with a digital display OR a temp sensor.
To add those you need to spend an additional $215, bringing the total cost to $579! Yikes!

There just has to be a more affordable option.

 

[SternWake]

Not sure if this can handle your proposed 300 watt panel, but it is a compact unit:

http://www.blueskyenergyinc.com/uploads/pdf/BSE_SB2512i(X)-HV_datasheet.pdf

Once needs to add the IPN pro remote for a display, and to change voltage settings/durations, and the price doubles with this addition, but it is a full function battery monitor as well counting AH into and out of the battery and displays a % as well as an AH from full as well as a bunch of other measurements.

I have the SB2512i I got in 2007. No battery temp sensor, and my particular MPPT controller requires 12v nominal panels, 24 or 36v nominal not acceptable.

The HV(high voltage) version in the link can handle higher voltage panels.

I really wish i spent the extra 35$ at the time for the Sb2512ix model which does have the ability to use a battery temps sensor and some other features too.

 

[BigT]

Not sure if this can handle your proposed 300 watt panel, but it is a compact unit:

Well if Watts divided by Volts = Amps, it should work just fine.  (300W/12V = 25A).  

Theoretically, and using that same math, my 190W panel should be matched with a 15.8A charge controller, but I was sold a 15 Amp.   :s

What about this:  It's a little more expensive but comes with a digital readout.  http://www.amazon.com/Blue-Sky-Ener...69&sr=8-2&keywords=Blue+Sky+charge+controller

They also have a 30 Amp model.  http://www.amazon.com/Solar-Boost-3...69&sr=8-1&keywords=Blue+Sky+charge+controller

The only difference I can see, besides the Amp rating, is that the 30 Amp model has a LED readout where the 25 Amp uses a LCD readout.  

I wonder if my Morningstar temp sensor http://www.amazon.com/Morningstar-R...r=8-1&keywords=morningstar+temperature+sensor would be compatible with the Blue Sky cc you linked to?  
The one you suggested is $192.

 

[ZoNiE]

Midnight Solar KID. With a Kid, you don't need a Trimetric as you can get a shunt, a whizbang (Their name) and you have all the features. I run one with 3X 135W Kyocera panels. Works great, and is very nice to my elderly batteries. The kid is also fully programmable, and you can set your charge voltages and times.

Northern AZ wind and sun sells them the cheapest, and Solar Penny in Mesa AZ is also pretty cheap, where I bought mine.

http://www.midnitesolar.com/pages/kid/index.php

http://www.solar-electric.com/midnite-solar-kid-mppt-solar-charge-controller-black.html

Run their SIZING TOOL to help decide what panel you want.

 

[SternWake]

I've not really kept up with charge controller offerings.

One can add a voltmeter or Ammeter separately. The basis of choosing a charge controller should not be based on whether is includes a display, but whether its absorption voltage and duration are adjustable, as well as float voltage, and whether it can handle the intended solar panel(s) output with some room to spare.

I forget the reasons why, but the Blue sky SB 2000 or 3000 models were undesirable to me when I was researching. back in '07

I'm going to have to bow out of contributing to this particular thread. My experience with Charge controllers is limited to the BlueSky 2512i, and the IPN pro remote battery monitor. I've not researched the latest offerings and can offer no opinions. I am happy with my BlueSky products, but wish I had purchased the slightly more expensive model with a battery temp sensor.

 

[BigT]

I'm going to have to bow out of contributing to this particular thread.  

The basis of choosing a charge controller should not be based on whether is includes a display, but whether its absorption voltage and duration are adjustable, as well as float voltage, and whether it can handle the intended solar panel(s) output with some room to spare.

No problem.  Thanks for all your help!  I admit that I didn't think of the absorption rate or duration settings. Thanks for reminding me. I'll go back and read more of the specs on the 2512i.

 

[BigT]

"Blue Sky Energy's Solar Boost 3000i solar charge controller charges 12V batteries at up to 30 amps from conventional 36 cell 12V PV modules. Patented MPPT technology operates the modules electrically in a manner that harvests all available PV power and can increase charge current up to 30% or more compared to conventional PWM type controllers. The voltage step-down operation of the MPPT power converter also allows use of higher voltage lower cost 60 cell grid-tie PV modules at up to 22 amps of output current. The process of converting the much higher 60 cell input voltage down to battery voltage may produce a charge current increase approaching 200%. Solar Boost 3000i's sophisticated 3-stage charge control plus auto/manual equalization optimally charges flooded, GEL and AGM lead-acid chemistry batteries. A user configurable auxiliary output is also provided which can serve as either a 20 amp LVD load controller, 20 amp lighting controller with LVD, or 2 amp auxiliary battery charger for a second battery such as the engine start battery in an RV. The low power LED display combines excellent readability with very low power consumption, includes an automatic night time diming feature and may be turned off completely if desired. The high accuracy display shows battery voltage, input & output current, auxiliary battery voltage, and computes total solar charge amp-hours produced. To provide optimal charge control for various battery types all digital setpoints for charge control and load control are user adjustable."

 

[jimindenver]

I'd have to see the panel specs to tell you if the new eco-worthy could handle it. You certainly would be pushing it's 20a limit at times even mounted flat. It has adjustable float and absorb voltages and now up to 300 minutes in absorb and equalization to boot. However it has a Voc limit of 50v so you would have to match it to the panel. I've seen 300w poly panels with a 45 Voc, so there is a chance. I've been using them for three years and they do what they say they will. You can get lucky and get them in auction with free shipping for $85.

I have known of a few using the EP solar/ tracer line up without complaints. you might check them out too. They come with more features like temp comp and are slightly more expensive for it. Many other solar companies are rebadging the tracer MPPT's but they are last years model.

The Morningstar 15a MPPT is way under sized for the panel. Nice controller but 230w is it's limit without clipping.

Morningstar, Rogue and Midnite all make expensive high end controllers if you need the control and features. I have the Morningstar 60a MPPT controller and yes it is big. A large part of that is the fins on the heat sink. When you run these controllers at full blast all day, they put off some heat. So much that I ditched any plans of mounting my controller inside my trailer. Some controllers use fans and who wants to listen to that.

The trick is finding the right balance of budget, features and size.

 

[BigT]

Hmmm.. Just noticed this line on the spec sheet for the Blue Sky 3000i.  
Blue Sky Energy’s new Solar BoostTM 3000i solar charge controller charges 12V batteries at up to 30 amps from conventional 36 cell 12V PV modules.

The Infinium 300 Watt panel I'm currently looking at has 72 cells.  Is this going to be a problem?

 

[ZoNiE]

Match the Voc and Isc from the panel to the specs on the controller. Most MPPT controllers handle much higher voltages because they convert that to charging current, where PWM controllers convert excess energy to waste heat.

 

[BigT]

What's Voc and Isc? And where's the "Dork" smilie when I need it?

 

[Optimistic Paranoid]

V is for volts and I is for amps, and no, I never understood why they didn't use A either.

in this case, Voc means Open Circuit Voltage.  In other words, how much voltage does the panel produce if you just set it up in the sun and hook a multi-meter up to it.  Think of this also as how much voltage it produces with no-load hooked up to it.

Isc means Short Circuit Amperage and it's basicly the same thing.  Hook your multi-meter up as an ammeter to the two wires on the panel, and how much current does it produce with no load attached.  Since you are running current from the positive side of the panel to the negative side, with no load, it's considered a short circuit rather than an open circuit.

If you want to get into it further:  http://forum.solar-electric.com/for...inners-corner/18083-voc-vmp-imp-isc-explained

Regards
John

PS you don't have to actually measure Voc and Isc with a meter, the panel should LIST these as standard specs.

 

[BigT]

Hmmm.. Just noticed this line on the spec sheet for the Blue Sky 3000i.  
Blue Sky Energy’s new Solar BoostTM 3000i solar charge controller charges 12V batteries at up to 30 amps from conventional 36 cell 12V PV modules.

The 300 Watt panel I'm currently looking at has 72 cells.  Is this going to be a problem?

Just as I suspected, it won't work with a 72 cell panel (duh).  The specs state that it will work with a 36 cell, 12 Volt panel.  A little further down the paragraph, however, is says "[font=verdana, arial, helvetica, sans-serif]The voltage step-down operation of the MPPT power converter also allows use of higher voltage lower cost 60 cell grid-tie PV modules at up to 22 amps of output current. [/font]"  

[font=Arial, Helvetica, sans-serif][font=tahoma, arial, helvetica, sans-serif]Electrical Properties (STC*)[/font][/font]

• [font=tahoma, arial, helvetica, sans-serif]MPP voltage (Vmpp): 32.1[/font]
• [font=tahoma, arial, helvetica, sans-serif]MPP current (Impp): 9.52[/font]
• [font=tahoma, arial, helvetica, sans-serif]Open circuit voltage (Voc): 40[/font]
• [font=tahoma, arial, helvetica, sans-serif]Short circuit current (Isc): 10.1[/font]
• [font=tahoma, arial, helvetica, sans-serif]Module efficiency (%): 18.0.6[/font]
• [font=tahoma, arial, helvetica, sans-serif]Operating temperature (°C): -40 ~ +90[/font]
• [font=tahoma, arial, helvetica, sans-serif]Maximum system voltage (V): 1000 (IEC), 600 (UL)[/font]
• [font=tahoma, arial, helvetica, sans-serif]Maximum series fuse rating (A): 20[/font]
• [font=tahoma, arial, helvetica, sans-serif]Power tolerance (%): 0 ~ +3[/font]

Wouldn't the recommended 20A fuse suggest that the output would less than 20A max?

I believe these are the two panels they are recommending.  

http://www.mlsolar.com/lg-monox-305...mm-frame-solar-module-module-efficiency-18-6/  305W

http://www.mlsolar.com/lg-monox-295...mm-frame-solar-module-module-efficiency-18-0/  295W

 

[blars]

That's the fuse between the panel and controler, at higher volttage and lower current (amps). Isc is 10.1 amps, so the fuse is almost double that.