DMPPT

[ask first]

Are these still available? I watched a video and just want to make sure he said it was OBSOLETE. If so what do we replace it with?

[Dacian Todea]

There was just no demand for the DMPPT450 and so it was not cost effective for me to continue to build that.

The SBMS0 + DSSR20 with diversion can be used to do most of the functionality of the DMPPT450 when both battery and heating is needed.

I may consider a smaller version of the DMPPT450 likely a DMPPT60 but there are no promises as I do not know if I will have the time to design and build that.

[Bjorn Teani]

Hello Dacian,

"The SBMS0 + DSSR20 with diversion can be used to do most of the functionality of the DMPPT450 when both battery and heating is needed."

Could you elaborate a little or point me to a schematic ? I'm confused on the multiple resistive sizing and wiring...

[Dacian Todea]

Bjorn,

You can check the DSSR20 / DEXT16 user manual for details https://electrodacus.com/DSSR20/DSSR20.pdf

[Bjorn Teani]

Dacian,

I expressed myself badly... I'm having trouble designing my system. What I'm missing is a practical example for the wiring of 3+6 300W PV used to charge a battery pack and heat water using bridge rectifiers. I search the forum but couldn't find any.

[Dacian Todea]

Bjorn,

You mean setup for a dual PV array ?  What is your battery capacity ?

For dual PV array setup is simple you just have EXT IO4 set as type 1 controlling the small PV array 3x 300W and then the EXT IO5 set as type 6 controlling the large PV array 6x 300W then set a max charge limit say 30A in the DMPPT settings menu.

The Dual PV array is explained in the SBMS0 user manual.

If you have specific questions then ask and I will try to answer.

I see you got 5x DSSR20's but you have just one DEXT16 so maybe you only want heating from one of the two arrays else if you wanted heating from all panels you will have needed two DEXT16

[Bjorn Teani]

My initial plan was 10 panels in one array. But I'm thinking of optimising charging and heating by using two arrays of different size and on the heating side, switching from thermal resistance to bridged diodes. I'll try to draw all that as best as I can and I will show it to you.

[Dacian Todea]

If your battery is large enough in capacity to handle the 10 panels so at least 400 to 500Ah then you do not need a dual PV array (there will be no advantage) but if your battery is smaller than 400Ah then it will sort of be required to split the array in two as else charge rate will be to high for the battery.