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BenandAmber
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Joined: 16/02/2019
Location: United States
Posts: 961

Posted: 10:28pm 09 Mar 2019

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Some of you that are talented enough to do so should manufacturer a kit for a good mppt controller one that could be self built would make it easy on all of us mppt is so expensive and it's like a box of chocolates you never know what you're going to get I have a computer programmer in my family if there's any way she could help she would do so some of the older computers were very very reliable as long as you didn't have them hooked up to the Internet and wasn't downloading new software onto them would run for years and years flawlessly some of the old Pentium one computers I've seen run for 15 years without a problem other than dust-collecting inside

just my two centsEdited by BenandAmber 2019-03-11

be warned i am good parrot but Dumber than a box of rocks

Solar Mike
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Joined: 08/02/2015
Location: New Zealand
Posts: 1138

Posted: 06:22am 11 Mar 2019

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BenandAmber said ... a kit for a good mppt controller one that could be self built would make it easy on all of us...

Would be a good idea, I have made a few at various power outputs, getting suitable quality components that will last are not cheap, the buck inductor has to have a specific designed core using known spec materials, in the end I had to get my cores from micro-metals in the USA, nothing available here in NZ or from the likes of AliExpress etc. High ripple caps have to be used again of known spec. Would cost prob $250-300 to build with say 200 vdc input and 60-100 amps charge output @48 volts; about the same cost as a 300w PV panel.

Off the shelf units here in NZ cost $600 - 1200 for similar spec.

Using quality components, no reason 15+ years life. However it would possibly be more cost effective to make a simple PWM controller and just add extra panels to cover any losses.....

What sort of specs were you thinking of....

Cheers
Mike

poida

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Joined: 02/02/2017
Location: Australia
Posts: 1419

Posted: 08:59am 11 Mar 2019

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Agree with using PWM only with extra panels.

Most days in a year we have here in Melbourne a lot of cloud cover. This means about 1/5 or less peak power from a panel. MPPT potential benefit on 1/5 of peak power is about 1/2 of SFA (a very small quantity, that was a technical term..)
Instead, just put as many panels you can afford and have space for, onto roof of house, chook shed roof, car port roof, etc. Just get panels in some area away from close tree shade.
Then get some PWM control on to sensibly grouped and wired arrays of panels.

Sit back and enjoy good solar power harvest over a wide range of weathers.

Even then, some days when all you see are dark rain clouds all day mean you will never get enough energy from the panels. In my experience, those sorts of days give about 1/30th of peak power.

My system has 3kW with a MPPT (Morningstar 60A) and another 3kW with a PWM controller.
I would have more panels but I've nearly run out of roof area.

wronger than a phone book full of wrong phone numbers

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