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Godoh
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Joined: 26/09/2020
Location: Australia
Posts: 169

Posted: 04:57am 13 May 2022

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I have seen some articles here about home made MPPT controllers, they look very complex to me.
I need to replace my damaged controllers and want to control the following.
24 volt battery bank
90 volts DC panel voltage
60 amps or above current from the controllers to the battery.

Many years ago I saw some stuff that was being done by Oztules on home made regulators. Just wondering if anyone here knows of a simple circuit to use for this purpose and where I can get circuit boards made in Australia.
I have a board design for a project that Oz did but it is only a .png or pdf file.
Do any manufacturers work from pdf files?
Hope someone knows
Thanks
Pete

Murphy's friend

Senior Member

Joined: 04/10/2019
Location: Australia
Posts: 283

Posted: 05:09am 13 May 2022

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Hi Pete,
The PCB manufacturers usually require Gerber files.

My home made MPPT controller to Poida's design works very well with a 40A current limit.
At 60A you start looking at expensive 2oz PCB's.

Godoh
Senior Member

Joined: 26/09/2020
Location: Australia
Posts: 169

Posted: 10:25pm 17 May 2022

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HI Murphy, thanks for the reply. I have been working my way through the giant article on Poida's regulator.
There seem to be lots of revisions, is there a page where the end design is shown.
I would like to have a go at building a couple myself.
The victron regulators I had are dead and the company decided to pot them in epoxy which makes them non repairable.
The agents in Tassie said that their tests showed that the internal fuse is blown, this according to them means the battery was reversed at some stage.
Total gobblegook the agent said normally there are fuses on the input side of them when they are installed and they should have blown first. Well mine had circuit breakers and they did not trip.
Potting things to make them non repairable is a rotten practice in my mind.
So if there is a final design, which I am guessing is the one you made , I would like to have a go.
Thanks
Pete

poida

Guru

Joined: 02/02/2017
Location: Australia
Posts: 1117

Posted: 01:27pm 20 May 2022

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I have had good results with 2 oz copper boards.
The firmware is mature now.
My home system uses 2 of the mppt regulators.
I have tested them at 45 Amps for hours on end with no problems.
Peak power testing at 3kW into a nominal 1 Ohm load just makes
some pcb traces warm.

efficiency testing always showed they were about 95% +/3% but likely
92% near the high power levels. It's hard to get even 5% accurate using
cheap clamp meters etc. All I know is they don't get very warm at all
so they are efficient.

my last post at the mppt thread was a victory lap showing 5MW.hr total energy
from the 2 mppt controllers. I am very proud of this.

building these is easy.
In your situation I would not build one for the 60A load.
I would build two, assuming you can split the input into two
similar sized power inputs. Maybe you can not.
Nicks has run his at those sort of power levels.

I can not give you the Gerber files for PCB manufacture since
they are not mine. They are Nicks's. I am sure he will be OK
if I send you them after I ask him (or you ask him.)
If I do not ask him first then that would be rude

Nicks's board is just as good as Wiseguy's board in my opinion
when looking at efficiency and reliability.

so the steps forward are:
get a few PCB made using Nicks's design
buy a few parts. make a couple of chokes. Get some good 100V 470 or 1,000uF caps
you don't need as many as the PCB has footprints for.
Get a handful of Arduino Nanos
2x 12V-12V isolated dc converter modules
2x TLP250
etc. see the BOM

Building them is easy.
programming the nano is simple
configuring the mppt/nano is easy and must be done (your battery needs your
charge regime)

I am happy to help you (and anyone else) with making their mppt controllers.

wronger than a phone book full of wrong phone numbers

Godoh
Senior Member

Joined: 26/09/2020
Location: Australia
Posts: 169

Posted: 10:07pm 20 May 2022

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Thanks for the reply poida. Sounds good.
One thing is that my system is 24 volt, is it just a matter of changing stuff in the nano program or are there other considerations?
I have 4 different arrays at the moment so would make at least 4 of them.
I will pm Nick and ask him for the gerbers.
Thanks
Pete

Murphy's friend

Senior Member

Joined: 04/10/2019
Location: Australia
Posts: 283

Posted: 07:03am 21 May 2022

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Pete, sad to hear that you too are a victim of those dreadful Victron solar regulators.

If you have trouble with obtaining nick's Gerber files you can try mine, they are OK for a 1oz copper board & 40Amps continuous. They also fit a cut short Aerosharp heat sink.
Before you start, check if you can buy the Allegro current sensors, a builder here could not find a supplier and is designing his own which will fit my PCB.
Poida was keen to re cycle the sensors from the Aerosharp but I found them too fiddly so they will not fit on my PCB.
I used a small DC/DC module to get the 5V for the Nano.
I used re cycled capacitors from scrapped inverters.
The choke *is* important, if you get it wrong it will be noisy and get hot. Check my MPPT build for some ideas.

Godoh
Senior Member

Joined: 26/09/2020
Location: Australia
Posts: 169

Posted: 06:00am 22 May 2022

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Just wondering, I have box of 1000 uf 63 volt caps, would it be fine to series them up. That way i figure I would have 500uf 126 volt caps.
As I already have them, it would be great to use them.
I like the idea of through hole components so the mind is still ticking over.
Pete

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