Please suggest a MPPT controller for me?
- Thread starter Bbasso
- Start date
This could get you started and not break the bank:
http://www.amazon.com/gp/product/B00FF1KGT4?gwSec=1&redirect=true&ref_=s9_simh_gw_p86_d0_i1
But only if you are series wiring the panels. If they are wired parallel, just use a Morningstar Sunsaver 20 PWM controller.
http://www.amazon.com/gp/product/B00FF1KGT4?gwSec=1&redirect=true&ref_=s9_simh_gw_p86_d0_i1
But only if you are series wiring the panels. If they are wired parallel, just use a Morningstar Sunsaver 20 PWM controller.
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jkam
nomadic man
I have the Morningstar Sunsaver MPPT 15 and it works great.
Also have the remote meter which is handy to monitor what is going on.
Not the cheapest option out there but well worth the cost for me.
http://www.morningstarcorp.com/products/sunsaver-mppt/
http://www.morningstarcorp.com/products/remote-meter/
Also have the remote meter which is handy to monitor what is going on.
Not the cheapest option out there but well worth the cost for me.
http://www.morningstarcorp.com/products/sunsaver-mppt/
http://www.morningstarcorp.com/products/remote-meter/
DiploStrat
Expedition Leader
I have this: http://www.amsolar.com/home/amr/page_213_14/solar_boost_3024il_mppt.html
Trouble free for almost two years and, with the ipnPRO you get full hour counting meter. Very programmable, but, at 40A, may be more than you need.
Trouble free for almost two years and, with the ipnPRO you get full hour counting meter. Very programmable, but, at 40A, may be more than you need.
LeishaShannon
Adventurer
Victron 75v/15A for ~$100 with 5 year warranty.
I'd be weary of "MPPT" controllers that can't handle high input voltages (e.g., less than 75v) as they're probably just a PWM controller badged as MPPT. Very common on eBay!
I'd be weary of "MPPT" controllers that can't handle high input voltages (e.g., less than 75v) as they're probably just a PWM controller badged as MPPT. Very common on eBay!
jonyjoe101
Adventurer
if you have your panels in parallel, then mppt wont work for you. Mppt needs high voltage (over 30 volts to work). That said I use the ecoworthy 20 amp model on my 240 watt panel and get about 12 amps from it and seen it go as high as 15 amps. Its only rated max 45 volts, so if your 2 panels connected together equal less that 45 volts it will work. Its almost 3 years old working nonstop 7 days a week. With 200 watts you see about 10 amps with mppt, more if you aim the panels at the sun.
You can spend more money but you probably wont get any better charging. If you are going to stay parallel any pwm charger will work about the same.
You can spend more money but you probably wont get any better charging. If you are going to stay parallel any pwm charger will work about the same.
Wiring in parallel, you are wasting the capability of an MPPT controller and you may as well use a good PWM controller. The MPPT controller will still work, you just won't get that much extra power.
With your set up, if you wired in series, and raised your nominal voltage to close to 40, then the MPPT controller will do direct DC to DC conversion and work great. As an added benefit, you will have lower voltage losses in your wiring.
And my link above is repaired and good now. I also know that particular unit is about the least expensive but decent MPPT controller you can get. It is not one of the fake ones.
With your set up, if you wired in series, and raised your nominal voltage to close to 40, then the MPPT controller will do direct DC to DC conversion and work great. As an added benefit, you will have lower voltage losses in your wiring.
And my link above is repaired and good now. I also know that particular unit is about the least expensive but decent MPPT controller you can get. It is not one of the fake ones.
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LeishaShannon
Adventurer
I'm not sure thats correct for the OP. If his panels are http://www.renogy-store.com/100W-12V-Monocrystalline-Solar-Panel-p/rng-100d.htm , the Vmp is quite high at 18.9v , so with Vbatt at 13v or so a PWM controller would be pissing away over 30% of the panels output @ STC and probably closer to 20% @ NOCT with the panels in parallel.
With lower Vmp panels the PWM losses are smaller but the OP has panels with a relatively high Vmp.
I'd stick with parallel to minimise shading losses, unless OP knows he'll only be using the setup in shade free areas.
Bbasso
Expedition Leader
Yup, those are the panels I have.
I'm sure my CC is decent, but even with a bright sunny Florida day, the CC never showed full batteries. They were sitting at 13.4 but the LED indicator wasn't full.
I think I need a higher (user set-able) float charge. At least that's what I think it's called.
I'd really hate to take the new batteries and destroy them prematurely.
I can avoid shaded areas easily, but would hate to spend more money on connectors... know what I mean?
I know I can't have the best of everything but I was hoping for an even amount of everything. That's why I chose parallel wiring for the panels.
With the panels and the parallel wiring which I like to keep the same some of you guys stay at MPPT is perfect and some of you say not worth it... I'm a little confused. As I mentioned my PWM controller isn't showing full even after a full day that's why I think I need a different controller.
I'm sure my CC is decent, but even with a bright sunny Florida day, the CC never showed full batteries. They were sitting at 13.4 but the LED indicator wasn't full.
I think I need a higher (user set-able) float charge. At least that's what I think it's called.
I'd really hate to take the new batteries and destroy them prematurely.
I can avoid shaded areas easily, but would hate to spend more money on connectors... know what I mean?
I know I can't have the best of everything but I was hoping for an even amount of everything. That's why I chose parallel wiring for the panels.
With the panels and the parallel wiring which I like to keep the same some of you guys stay at MPPT is perfect and some of you say not worth it... I'm a little confused. As I mentioned my PWM controller isn't showing full even after a full day that's why I think I need a different controller.
LeishaShannon
Adventurer
The Victrons are fully programmable using their cable (or if you don't mind making your own a TTL->USB adaptor is about $2 on eBay)
I'm thinking they didn't bother to look at the Vmp of your panels. Its quite high which means a PWM controller is throwing away a fair chunk of your panels output. You mention 13.4v , at that voltage your panels are only putting out 13.4v * ~5.29A = 70W under ideal conditions but probably less due to the temperature / solar isolation at your location. A MPPT controller can make use of the extra 5.4v (30%) between 13.4v and the panels 18.9v , but in doing so it does lose 3-5% due to inefficiency of the conversion process.
The problem with all of these calculations is they're based on Standard Test Conditions or STC , which has the panel temperature at 25c and solar isolation at 1000W/m2 , but in the real world conditions vary and will rarely be "ideal" . The MPPT gains are likely to be lower during hotter months and possibly greater during the cooler ones.
If your existing CC can handle the extra power AND you can fit it somewhere, an additional panel could be better value than a MPPT controller.
You have great panels, at about the right open circuit voltage (VOC). If you run them in parallel, your wiring into the controller is at 18 volts at best. In that scenario, I doubt you'll see any difference in PWM vs MPPT charge controllers. So use a PWM controller which is more robust, and costs less. At 36 volts(ie in series), the same amount of power can be sent to your battery at 1/2 the amperage, resulting in less voltage loss, and less power lost to resistance heating. In the latter case you need an MPPT controller to do the DC to DC conversion and operate at max efficiency. Running a 36 volt panel into a 12 volt PWM would waste half of your solar power (wattage).
What gets lost in these discussions, is that these are very low power systems. Under 200 watts (or even 400 watts) the difference between PWM and MPPT is very small measured by a power meter into the battery. MPPT will always be better theoretically, but if you are running standard "12 volt" panels (VOC 18 or so) the difference is minimal. It's when you get into higher VOC panels that MPPT controllers really shine, because they can do the DC to DC conversion need to take advantage of the higher voltage panels.
I think your situation is an ideal one. You can run with an MPPT controller to take advantage of the inherent capacity of higher voltage panels/wiring(ie in series), or if something fails, you can use a cheap PWM controller and still get most of the function with some changes in the wiring(ie in parallel).
What gets lost in these discussions, is that these are very low power systems. Under 200 watts (or even 400 watts) the difference between PWM and MPPT is very small measured by a power meter into the battery. MPPT will always be better theoretically, but if you are running standard "12 volt" panels (VOC 18 or so) the difference is minimal. It's when you get into higher VOC panels that MPPT controllers really shine, because they can do the DC to DC conversion need to take advantage of the higher voltage panels.
I think your situation is an ideal one. You can run with an MPPT controller to take advantage of the inherent capacity of higher voltage panels/wiring(ie in series), or if something fails, you can use a cheap PWM controller and still get most of the function with some changes in the wiring(ie in parallel).
IdaSHO
IDACAMPER
And thats the kicker.
I will ALWAYS argue you should go for an MPPT controller. The benefits are proven. The only negative is cost.
That said, there is MUCH more value in high(er) voltage panels.
Im running just 200 watts, but the panels are 36 volt panels. The benefits are there.
Even with the "el-cheapo" MPPT controller. Which seems to be surviving just fine. All gravy so far.
Bbasso
Expedition Leader
I could fit another panel but loose very precious roof top space for carrying items (kayak), btw I just added the second panel and won't be adding any more.
I have seen upto 12.6 amps coming in with my old (crappy) battery, but with the new ones which are nearlyfull I see up to 5.1 when I kick on all the lights and fans. So I know the system is working.
The 13.4vts I mentioned earlier is during the last part of charging, the amps drop to .2 and lower. So doesn't that mean that the batteries are near full capacity?
If it's nearing full capacity why would the amps drop off (.0) before the light reads full?
I'm thinking the CC doesn't have a high enough preset to fully charge the big new dual agm batteries.
Am I wrong?
So am I right thinking a controllable (user set-able) MPPT CC would be the ticket to top off the batteries?
I have seen upto 12.6 amps coming in with my old (crappy) battery, but with the new ones which are nearlyfull I see up to 5.1 when I kick on all the lights and fans. So I know the system is working.
The 13.4vts I mentioned earlier is during the last part of charging, the amps drop to .2 and lower. So doesn't that mean that the batteries are near full capacity?
If it's nearing full capacity why would the amps drop off (.0) before the light reads full?
I'm thinking the CC doesn't have a high enough preset to fully charge the big new dual agm batteries.
Am I wrong?
So am I right thinking a controllable (user set-able) MPPT CC would be the ticket to top off the batteries?
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