MPPT Charge Controllers

[jenny2]

Does any one know of mppt charge controlers in the 20 to 30 amp range ajustable for agm batteries ?

[atmarine]

Check out Blue Sky in Cali. They offer good robust regulators

[richardhula]

I use a Blue Sky 2512i mppt controller for a pair of Kyocera 130 watt panels.

Its rated at 25 amps with acceptance/float voltages 14.2/13.2 volts which should be fine for AGM's.

Click on image for more info.

[cfarrar]

I have a Blue Sky 2512ix with the IPN remote display and battery temperature setting. 216 watts of solar panel panels, wired in parallel (ie, 12v system), charging a house bank of AGMs. On my battery monitor I regularly see 12.5 amps of charge, which is the full rated output of the solar panels. So the MMPT performs as advertised.

The factory settings are for 3-stage charging of AGMs (14.2 volts acceptance, 13.2 volts float). To change those settings you need the more expensive IPN ProRemote. I don't plan on changing the settings, though.

[dennisjay]

I have same Blue Sky setup as richardhula. It's worked flawlessly for three years.

[chuckr]

we have a 2512 blue sky with 3 130 watt kyocera solar panels -- it is stretched to the limit and we did talk to kyocera before adding the 3rd panel --
works great

chuck patty and svsoulmates
in deltaville boat yard for a water maker

[senormechanico]

I also have a 2512iX which works great, but I get a lot of AM radio interference.
Has anyone found a cure?

[MarkJ]

My two 120 watt pannels go straight into the batteries.
I've been wondering if I should get a controller and if these at about $200 they would fit in the "I can sell my bod for a hour" range.
52512i is $189 and the ix is $220 (others $499!)

Can anyone quanitfy the statement "charge current up to 30% or more compared to conventional charge controllers"
Does than mean my batteries get charged quicker? (A Yes / No answer would help)

Or is the explanation just big words to fuddle my brain making it better just to stay without one?

[cfarrar]

2512i is $189 and the ix is $220 (others $499!)

One difference - the ix will provide battery temperature compensation.

Can anyone quanitfy the statement "charge current up to 30% or more compared to conventional charge controllers"
Does than mean my batteries get charged quicker?

Short answer: Yes, if you're batteries are sufficiently depleted to accept your solar panels' full output.

Layman's explanation: A "12 volt" solar panel produces maximum current at a voltage of around 17.5-18.0 volts. But when you connect the solar panels directly to the batteries, the circuit's voltage will be limited by the batteries' voltage. The drop in voltage at the solar panel means a corresponding drop in current. Let's say the solar panels are forced to operate at 12.7 volts instead of 17.7 volts - that's a loss of 28%. Simply put, the MMPT allows the solar panels to operate at their rated voltage, while downstream it delivers current to the battery at a lower voltage for charging. This allows you to get your full rated solar panel output delivered to your batteries, assuming your batteries are depleted enough to take that many amps. There is some current loss through the MMPT controller itself, but this is slight.

Does it work? My panels are rated for a total of 12.5 amps at 17.7 volts, and that's exactly what my battery monitor shows flowing into my battery in the morning, even though the battery voltage is only 12.5 to 13 volts.

[Joe Simmons]

Originally Posted by MarkJ

My two 120 watt pannels go straight into the batteries.
I've been wondering if I should get a controller and if these at about $200 they would fit in the "I can sell my bod for a hour" range.
52512i is $189 and the ix is $220 (others $499!)

Can anyone quanitfy the statement "charge current up to 30% or more compared to conventional charge controllers"
Does than mean my batteries get charged quicker? (A Yes / No answer would help)

Or is the explanation just big words to fuddle my brain making it better just to stay without one?

Moreover, if you are using an MPPT controller with your panels wired in series, you will get superior low-light power generation.

As to the person earlier who has their panels in parallel- If you have a MPPT controller, why are you doing this?

Series(high voltage) is always more efficient(esp. in low light), if you can use it of course.

[Joe Simmons]

I just looked up that bluesky controller. It's maximum input voltage pretty low. Check your panels before putting them in series! Some panels (so-called 12V) you can run 2 in series, but many panels are now running 30ish volts.

There are other MPPT controllers on the market that will accept input voltage up to 140 volts.

[richardhula]

Originally Posted by Joe Simmons

Moreover, if you are using an MPPT controller with your panels wired in series, you will get superior low-light power generation.

As to the person earlier who has their panels in parallel- If you have a MPPT controller, why are you doing this?

Series(high voltage) is always more efficient(esp. in low light), if you can use it of course.

Joe if what you say is true why don't solar panel manufacturers make panels with enough cells to give around 36 volts (off load) the equivalent of what you suggest in wiring two "12 volt" panels in series, & corner the market by offering "the most efficient low light 12 volt panels available".

Moreover why are Blue Sky so dumb as to not offer a controller that will cope with these higher input voltage to charge 12 volt batteries - I'm curious

[cfarrar]

As to the person earlier who has their panels in parallel- If you have a MPPT controller, why are you doing this?

Here's my understanding (please tell me if I'm wrong):

With parallel wiring, when one panel is shaded you only lose that panel's output. With series wiring a single shaded panel creates significant loss of current.

The main disadvantage of a parallel (ie, lower voltage) system is that voltage drop creates a proportionally larger current penalty. However, I use heavy gauge wires (#2 below deck), plus the MMPT helps by keeping the circuit voltage at 17.5 volts. In any event, my system consistently produces the solar panels' rated current, even with a thin overcast. So it doesn't seem like the parallel setup is hurting me. Am I wrong?

Note - other Blue Sky controllers have higher voltage maximums and are better for parallel systems.

[richardhula]

Originally Posted by cfarrar

In any event, my system consistently produces the solar panels' rated current, even with a thin overcast. So it doesn't seem like the parallel setup is hurting me. Am I wrong?

No you are not - I too get full rated power (18 amps under ideal conditions), into my 12 volt battery bank from two Kyocera 130 watt panels in parallel.

[blahman]

Originally Posted by cfarrar

...Blue Sky 2512ix...
he factory settings are for 3-stage charging of AGMs (14.2 volts acceptance, 13.2 volts float)...

The manual for my 2512iX says it is factory-programmed for the specs of Trojan 105 6-volt batteries, and that it should be reprogrammed if used with AGMs. This reprogramming can be done WITHOUT the IPN ProRemote, via jumpers. The ProRemote allows it to be done with greater ease, and customization.


I also have 2512iX with IPN ProRemote and it's a great, very well priced controller. My 2x 130w SUN panels put out a lot of power thanks to the MPPT.

Thanks Blue Sky Systems!
~Aaron