Which MPPT Solar Controller?

[Rhian]

I am just about to fit new solar panels, 4 x 135 watt, and am wondering which controller to purchase.

I have been advised to use an MPPT controller as they are more efficient but not sure which one to use. Currently looking at the Bluesky solar boost 3024iL and the Morningstar Tri-star TS-MPPT-45.

We have a 12v system and are wondering if the 40 amp models will be big enough and if anybody has any experience of these 2 models or can recommend any others.

Thanks in advance!

[djmarchand]

Both controllers are going to be too small. Even considering just the nameplate ratings the 4 *135 will produce 45 amps of power into a 12 volt load. Many authorities recommend increasing the controller rating by 20% to cover vaugaries of solar panels and controllers. So I would go with a 60 amp controller.

And use really big wire if you are going to wire them in parallel and bring the main feed to the controller- 6 gauge at least. And you will need a 60 amp fuse near the battery.

David

[Bash]

One of the things I didn't consider when setting up my controller was the amount of heat the MPPT unit would generate while doing its thing. Unfortunately, I mounted the controller in a compartment that doesn't vent heat well. If I ever replace the system, one of the main things I'll investigate is how a given controller vents and handles heat.

[Strygaldwir]

Outback has worked very well for me for several years now.

[nhschneider]

We have two 235-watt panels and they're controlled by the Morningstar 45-amp controller. It's been working great for three years now.

Fair winds and calm seas.

[Roy M]

Bash, check out Catalog Frame. They have an automatic vent control unit that senses when a charger/alternator, alternate energy source raises the voltage to the point where the batteries outgas. It shuts off fifteen minutes after the charging ceases. I use one for my 740 Ah house bank, located down in the bilge area, with the exhaust gas going out to a locker discharging overboard. They are handy for engine room ventilation control, as well. Ooops! I forgot to say it's connected to a pancake ventilating fan. It's from a company called Yandina.

[GeoPowers]

Originally Posted by djmarchand

Both controllers are going to be too small. Even considering just the nameplate ratings the 4 *135 will produce 45 amps of power into a 12 volt load. Many authorities recommend increasing the controller rating by 20% to cover vaugaries of solar panels and controllers. So I would go with a 60 amp controller.

And use really big wire if you are going to wire them in parallel and bring the main feed to the controller- 6 gauge at least. And you will need a 60 amp fuse near the battery.

David

+1 to what David said. The charge controllers you are considering are too small for your array. I'd look into an Outback Flexmax 60, or maybe a Midnite Solar 150. I have the Flexmax 60, and it is pretty awesome.

FYI the Flexmax 60 handles up to 2 AWG if you are considering paralleling panels. I'm guessing from your wattage you might have Kyrocera's with a nominal 12V voltage rating? If so, I would consider a series-parallel set-up, or even a series connection if you are confident you will have minimal shading- it is better for lower light conditions like dawn, dusk, heavy clouds, etc.

Frank

[ExRonin]

I have a similar array (2 130W and 2 140W). I use 2 Blue Sky 2512ix units and they work extremely reliably, and are also quite economical. With the IPN pro remote monitor you have all the data you need on panel performance. Also don't forget to put an auto relay (30A) on the PV inputs to the MPPT's so you can kill the solar regulators when your are charging in other ways ( running the engine for example) so those regulators wont become "confused".

[Celestialsailor]

I also have a Blue Sky. It works very well. What I didn't like about them was the cheesy galvanized household electrical box they supplied for it. I made a SS box for it.

[Fuss]

Originally Posted by Rhian

I am just about to fit new solar panels, 4 x 135 watt, and am wondering which controller to purchase.

I have been advised to use an MPPT controller as they are more efficient but not sure which one to use. Currently looking at the Bluesky solar boost 3024iL and the Morningstar Tri-star TS-MPPT-45.

We have a 12v system and are wondering if the 40 amp models will be big enough and if anybody has any experience of these 2 models or can recommend any others.

Thanks in advance!

Morningstar says that the Tri-star TS-MPPT-45 is ok for 4 x 135w panels in either parallel or series configuration.

[noelex 77]

Originally Posted by Fuss

Morningstar says that the Tri-star TS-MPPT-45 is ok for 4 x 135w panels in either parallel or series configuration.

Yes the Morningstar 45 would be fine.

My vote, as sereral others have suggested is for the outback. Midnite are another option with the only controler that is, arguably, better than the outback for similar money. The only drawback with the Midnite is that it is a very new product without the long history of reliability that the Outback has.

[GeoPowers]

Originally Posted by Fuss

Morningstar says that the Tri-star TS-MPPT-45 is ok for 4 x 135w panels in either parallel or series configuration.

While the Tristar 45 MPPT is physically able to handle 4 panels, NEC says that the current rating of the controller must be equal to or greater than 125% of the solar array’s short circuit current output (Isc). That would be 36 amps. Not knowing the current rating of the panels in question I can't say for sure that it is over 36 amps, but it has to be close.

Similarly, even though the Flexmax 60's output current limit is 60 amps, if you read the manual the largest PV array that is supposed to be connected to it is 48 amps.

IMO they should call them the Tristar-36 and Flexmax 48!

Frank

[silverp40]

Blue Sky first came up with the MPPT concept, a very efficient way to maximize your PVs power.

Our Blue sky controllers have been both flawless over the last 3 years of continuous use. They also adjust the output when other sources of charging are present. 60 amp is correct for your application.

I have 2 friends with Morningstar units that have had issues with their PV controllers...

Good luck!

[noelex 77]

Originally Posted by GeoPowers

While the Tristar 45 MPPT is physically able to handle 4 panels, NEC says that [FONT=ArialMT][COLOR=#231f20][FONT=ArialMT][COLOR=#231f20]the current rating of the controller must be equal to or greater than 125% of the solar array’s short circuit current output (Isc). That would be 36 amps. Not knowing the current rating of the panels in question I can't say for sure that it is over 36 amps, but it has to be close.

Knowing the panels would be helpful.

The popular Kyocera 135 has a Isc of 8.37A. So 4 is 33.48 amps. In practice the Isc will not be seen, it only happens if the terminals are short circuited.

The nominal maximum solar input for the Morningstar unit is 600w, so 540w should be fine.

[jeremiason]

We have four Kyocera 135 Watt panels and three 85 watt panels run in series to a BLUESKY 6024HL 60 amp controller...

The nice thing about this controller is they let you run the pannels in series, accepting 36 to 48 volts, which generates more amperage output to the batteries...

The controller also accepts a second display head which can be mounted somewhere conveniant to monitor your solar power status.

Even with our mis-matched panels, I routinely make 40-44 amps per hour in direct sunlight... Of course your mileage may vary :-)

I also agree with the previous posting that any controller should be placed in an area that has good ventalation, as they all generate a certain amount of heat...