MPPT Controllers

[JusDreaming]

I have decided on the Kyocera 130/135 panels, but have not decided on which controller. I will only have two panels but may expand. But more concerned by brands of controllers

[barnakiel]

Most of the new types do a good job - convert the input to higher Volts then reduce it to whatever the battery can take and needs - sort of like a 3-stage regulator joined with a Voltage converter.

The older ones often just cut down the Voltage - less sophisticated, fewer Amphours out, but at least they do not let the panels cook the batteries.

b.

[Rising Star]

I have been using the Moringstar ProStar 15 with my 200W, 48V panel for just over a year. I am very pleased with it. It provides a constant, rotating readout of battery charge state, solar amps in, and load.

I use the smaller Morningstar controller for house battery bank panel which is a 50W panel.

[sailing now]

I have a 50amp Blue Sky w/ 4 kyrocera 130w panels. I see 30+ amps on sunny days. What I really like about the Blue Sky is that you can adjust the pots inside the box to maximize the output to your array.

[MarkJ]

Have you thought about the necessity of having one at all?

After reading all the bumph excluding some proriety, un tested, claims about increasing your power by 30% the only thing they seem to do is stop the pannels charging if your batteries hit 100%.

And that ain't gunna happen on a cruising boat because you just turn up the refrigerator a bit. Or install the freezer you always wanted.

And if you fly home for a month you just chcuk a towel over the solar pannel....


We have two 120 watt monocrystaline pannels about to be installed.... I really havent been given proof a regulator is necessary....

[Paul L]

Originally Posted by MarkJ

Have you thought about the necessity of having one at all?

After reading all the bumph excluding some proriety, un tested, claims about increasing your power by 30% the only thing they seem to do is stop the pannels charging if your batteries hit 100%.

And that ain't gunna happen on a cruising boat because you just turn up the refrigerator a bit. Or install the freezer you always wanted.

And if you fly home for a month you just chcuk a towel over the solar pannel....


We have two 120 watt monocrystaline pannels about to be installed.... I really havent been given proof a regulator is necessary....

I think you are going to have to watch your panels awfully closely to have 240 watts unregulated into your battery bank. I assume your bank is in the 400amp-hour range and wet cell(?). What voltage are the panels going to be charging at when the batts are reasonably charged? How's that match with optimum for long life of your batts?

That said, in your case you probably don't need to go the MPPT route, but it seems like a standard regulator would make sense.

Paul L

[Beach Cruiser]

We have the Bluesky SB50 with 4 Kyocera 135 watt panels and would see 30 to 40 amps in the Bahamas last winter.

Barry

[s/v Jedi]

Mark,

The MPPT controllers actually give you more Ah than going without the MPPT controller. You can check this yourself: find the output-curve for your panel (in the "manual" or website). Now, assuming you have a 12V system, during charging you will have something like 13.5V most of the time. Using that voltage, find the corrosponding output in the curve. You will see that it is significantly below the max. output of the panels.

The maximum output is achieved at a higher voltage, like 17V or 20V. You normally never get those high levels because your batteries pull it down to that 13.5V level. But the MPPT controller can do it, by reducing the load. It keeps tracking that max. output level during the day.

Also, you can connect panels in series instead of parallel when using a MPPT controller. This means output voltage goes up but current does not, allowing you to use a smaller size wiring and have less power losses in the wiring.

I agree with you about frying the batteries, that won't happen when you are a live aboard cruiser and keep an eye on things. That is the reason we removed an (old tech) controller years ago. But now, we are going to install a MPPT controller just for the extra power generated. Experiences from others (older threads here too) have convinced me plus the principle of operation is solid.

cheers,
Nick.

[CSY Man]

I am getting at least 10% more output thanks to the MPPT controller.

Perhaps 30% under ideal conditions, but I will take the 10% any day...

[schoonerdog]

MPPT are described and testing in Practical Sailor. I use a Outback for over a year with 600 watts of solar panels. It provides all the power needed for a 130 liter refrigerator, 110 liter freezer, and way too many lights, pumps, etc. On a sunny day I've seen 40+ amps being put out from the panels. Ideally you want enough power to be generated that on a cloudy day you would take all day to charge but be fully charged by sunset and on a sunny day you'd probably be topped off by 11am. Good solar setup also allows you to reduce your battery weight because you are now carrying batteries for night time draw, rather than 24 hrs typically needed by an engine driven charging system which is run once a day. As to not needing a regulator at all, that's really not a well thought out idea. If your main charging system is insufficient to keep your batteries topped off during the charging cycle, then your running a deficit and are going to slowly kill your batteries. If it IS big enough to keep your batteries charged on a daily cycle that it WILL fry your batteries if unregulated.

[s/v Jedi]

Schoonerdog,

Liveaboards always need more power so it's always an ongoing process to make more. For many, solar charges during the day, windgens 24 hrs and a genset to top it off now and then.

The scenario you describe is one where the solar panels are the only charge-source used and if so, you are correct that you need a controller and fully charge the batteries. But, most cruisers cycle between 50% and 80% with a 100% charge every couple days to a week.

It can be better, I know, but for example our Trojan L16's are doing that for 5 years now without much trouble so it isn't really killing the batteries quickly.

I am interested in the Outback controller too. What are the max. ratings for solar array Watts and input voltage? I have 6 panels 110W each so 660W and I think their open voltage is 22V (Shell/Siemens panels). I'm still searching for the perfect controller for them ;-)

cheers,
Nick.

[ka4wja]

Denny and Diane,

A few quick thoughts...

1) MPPT controllers DO work....and whether you use Blue Sky or Outbacker, just choose one that meets your current needs, with a fudge margin, and allows for expansion....and all will be fine....


2) I've been using solar charging for quite some time (since early 1980's on land, and for the last 10 - 12 years at sea), and have been quite happy with my Blue Sky 2512ix MPPT Controllers for the past 3 years....

They DO provide me with an increase in charge current....with my 4 x Kyocera 130 watt panels (520 watts), I do actually see 240 to 260 A/H per day of charge put back into my battery bank (assuming I have drawn that much, which only happens when sailing long passages with 24/7 autopilot, etc.).....

For the details, have a look at the photos and article I wrote, about my choices, installation and my results / performance....
Solar Panels


3) Have a look at the SSCA discussion boards......you'll find a wealth of info on the Energy Forum, that will help you.....
SSCA Discussion Board • Index page


4) Do the best you can to keep your panels from being shaded, and you'll LOVE solar......and you'll wonder why you didn't do it sooner!!!



Good luck and sunny skies....

John

[s/v Jedi]

Hmm, to follow up on my own post, the Outback controller seem to handle up to 150V DC input and can charge a 12V battery bank with that at 60 or 80 amps. The 60A version must be the one for me!

Does anyone know of another controller that can take 6 12V (36 cell) panels in series and output 50+ amps to 12V?? This is the first one I found, Blue Sky doesn't have it.

cheers,
Nick.

[s/v Thea]

Nick,

Another option would be to use three 2512ix (they link together to act as one controller), two panels in parallel per controller. That way if you loose a controller you only loose 1/3 of your output.

Doug

[ka4wja]

Originally Posted by s/v Jedi

Hmm, to follow up on my own post, the Outback controller seem to handle up to 150V DC input and can charge a 12V battery bank with that at 60 or 80 amps. The 60A version must be the one for me!

Does anyone know of another controller that can take 6 12V (36 cell) panels in series and output 50+ amps to 12V?? This is the first one I found, Blue Sky doesn't have it.

cheers,
Nick.

Nick,
Actually Blue Sky does have one like that......their Solar Boost 6024H, handles up to 140vdc input and is field adjustable for either 12vdc or 24vdc system charging....

Blue Sky Energy Inc. | Solar Boost 6024HL
and
http://www.blueskyenergyinc.com/uplo...Hdatasheet.pdf


I found the guys at Blue Sky to be very professional and very "into" solar......very "engineering - geeky".....
Nice guys!!


Good luck and sunny skies...

John