Confused about panels setup for a Victron Multiplus II 48/3000/35-32 GX

[nicokneler]

Hi everyone, I'm Nico and I'm happy to be part of this community

I'm building a house on a delta in Argentina, and while we do have powerlines, they have a lot of problems so I want to be set up with a solar energy kit.
I have a Victron Multiplus II 48/3000/35-32 GX, a MPPT 150/35 also from Victron, and a 500A Smart Shun.

I'm having trouble figuring out what would be an optimal panels/batteries combo for this setup, I've been searching but I haven't been able to come up with a solid answer.

Also wondering if there are any other components that are costly and important for this setup, as I could have someone ship them from abroad (things are very expensive in Argentina at the moment, panels and batteries I will have to purchase here).

I will appreciate any help you can provide!

 

[sunshine_eggo]

The mppt can accept an array with up to 150Voc, but you must allow margin for cold weather.

The 35 means 35A output to the battery, so the most it could deliver to a 48V battery nearly full charge would be 35A * 58V = 2030W.

Typical 72 cell panels may only have up two in series.
Typical 60 cell panels may only have up to three in series.

The MPPT is tolerant of over-paneling. Do not exceed 150Voc (plus temperature margin) and don't exceed PV input limit of the controller at 40A.



Using 3S 60 cell panels at about 100Vmp, and an Isc of 40A (Imp about 36A), you could get about 3600W on the controller without causing damage. It would only allow use of 2000W of it, but it will produce 2000W for most of the day.

 

[nicokneler]

The mppt can accept an array with up to 150Voc, but you must allow margin for cold weather.

The 35 means 35A output to the battery, so the most it could deliver to a 48V battery nearly full charge would be 35A * 58V = 2030W.

Typical 72 cell panels may only have up two in series.
Typical 60 cell panels may only have up to three in series.

The MPPT is tolerant of over-paneling. Do not exceed 150Voc (plus temperature margin) and don't exceed PV input limit of the controller at 40A.

View attachment 203078

Using 3S 60 cell panels at about 100Vmp, and an Isc of 40A (Imp about 36A), you could get about 3600W on the controller without causing damage. It would only allow use of 2000W of it, but it will produce 2000W for most of the day.

Thank you so much @sunshine_eggo for this explanation!

I'm still a bit confused, after work today I will look into what all that means and try to figure it out.

For panels I was looking at Amerisolar panels which I can find in my country, they are 450W 120 cells. I'm unsure if these would work, and how many I should install for optimal performance. I can try to find ones with less cells in them.

Also for batteries, 48V 100A lithium batteries are super expensive here (+$3000) so I was looking into buying 4 100A 12V Gel batteries. I'd love your opinion, if it's not too much trouble.

Thanks again!

 

[sunshine_eggo]

Thank you so much @sunshine_eggo for this explanation!

I'm still a bit confused, after work today I will look into what all that means and try to figure it out.

For panels I was looking at Amerisolar panels which I can find in my country, they are 450W 120 cells. I'm unsure if these would work, and how many I should install for optimal performance. I can try to find ones with less cells in them.

120 cell panels are usually half cut cells, and it's like having two 60 cell panels in parallel, so this controller can likely handle 3 in series.

Also for batteries, 48V 100A lithium batteries are super expensive here (+$3000) so I was looking into buying 4 100A 12V Gel batteries. I'd love your opinion, if it's not too much trouble.

GEL are okay. You won't get the life out of them that you will get out of Lithium. They tend to have a good cycle life, but only at lower currents and only down to 50% charge. It would probably be better to buy 200Ah of GEL to ensure you have 100Ah of usable capacity.