Goal Zero has an external MPPT now for the 1000 & 1400

[PattySprinter]

Goal Zero has a lithium MPPT solar charging optimization module MPPT ($79) for the 1000 & 1400 - I think it pops into the top cavity under the lid.
I read that the new GZ 3000 comes with it installed.
They state it can improve charge times by 40%.

 

[John61CT]

Interesting, link to specs sheet or other​ docs?

Wonder if it only works as an add-on, or could be independent?

 

[PattySprinter]

Interesting, link to specs sheet or other docs?

Wonder if it only works as an add-on, or could be independent?

http://tinyurl.com/y8trkjbt

There is the page on it ... I ordered it - the price seems reasonable ...

 

[John61CT]

So 350w max input through the APP, in real life I bet could handle four 100w Isc panels

Weird that max volts is 22, 12V nominal panels only. I thought MPPT needed a higher range to do its 'magic'. Note also does not help reduce panel wire gauge for putting 'remote' panels way off into the sun.

No mention of any setpoint adjustability, the output charging algorithm would need to observed, wonder how long it holds Absorb, and whether it floats.

But I'd bet it's V absorb is higher than the 13.8V I'd want. Might be good for some lead chemistries though?

If so yes, great price for MPPT 25A.

 

[frater secessus]

MPPT works ok with with banks and panels at the same nominal voltage. The advantages can, as you suggest, be limited by the reduction in headroom. I still think MPPT is worth the price difference with 12v panels, but I understand why others might not.

Maybe GZ capped it at 22v so they could use less costly hardware or need less cooling; the resulting price is certainly a good one.

 

[John61CT]

My understanding is that the MPPT can be designed to operate within any arbitrary range.

The cynic in me suspects maybe they just have buck DC-DC conversion going on to give greater output over plain PWM.

Yes obviously this lower voltage range means cheaper mfg costs, and for their target market the nominal 12V panels are more common, less choice = easier sell, lower support costs.

I would hope that the unit continues to harvest at least some power when panel output V drops down to say 15V, unlike Victron which won't even start until panel V is +5 over the battery.

 

[frater secessus]

Sure could be. There were some crazy cheap "MPPT" controllers (like $20) that upon teardown were just doing conversion as you describe. I think those were running the panels 2v higher than the charging voltage.

 

[jimindenver]

A 22 Voc limit? OUCH

Most mono 12v panels have a 22+ Voc to start with. Polys are just above 21 Voc but with the right temperatures/altitudes will climb. Most MPPT controllers just do not like their Voc rating exceeded.

I am wondering if this is a partial charge controller and that is why it is called a optimizer. I say this because originally the panels would plug straight in meaning that there is a PWM controller built in. A true MPPT controller already has a PWM portion that the buck converter sends the power to. You could not have two in line so possibly this optimizer is everything but the PWM unit since it will already be sending the power to a PWM controller.

So the price is nice but it may be of use with their solar generators. Outside of that I think I would stay with a Eco-worthy 20a or Victron as they are stand alone controllers.

 

[John61CT]

The Bogart Trimetric supervising two SC-2030s is a really sweet setup, but PWM only.

I'm thinking something like this feeding the panel input may give bit of an overall boost, when the 62A limit becomes a constraint.

Whether that's worth the extra $ is another question.