diy solar

diy solar

Please check for safety my 24v 1000w 5S2P rig

Hi kenkoh,
1) The solar panel array is wired properly as far as I can tell. Cable gage seems fine as well.

2) The solar controller's amperage rating is insufficient! As your batteries can go down as low as 10.5V each (together 21v) there is a huge voltage difference between the solar panels (92.5V) and your battery, which means your solar charge controller will have to drop the output voltage, thus augmenting the current: ~10.8A x 92.5 / 21V = ~ 47A
You should buy a 60A or higher controller to give it some rest.
Then 60A fuse (47A x1.25) for solar charge controller to battery + 6AWG or 4AWG gage wire.

3) Your battery-to-inverter fuse seems oversized (or is that a shunt?). 1500W continuous / 21v = 71 Amps x 1.25 = 90A
You could get yourself a 100A fuse! Also 2/0 cable would be safer, but 1/0 seems fine.

Glad to help!
 

Attachments

  • 1613381860034.png
    1613381860034.png
    225.3 KB · Views: 15
  • DC_wire_selection_chartlg.jpg
    DC_wire_selection_chartlg.jpg
    85.8 KB · Views: 16
Hi kenkoh,
1) The solar panel array is wired properly as far as I can tell. Cable gage seems fine as well.

2) The solar controller's amperage rating is insufficient! As your batteries can go down as low as 10.5V each (together 21v) there is a huge voltage difference between the solar panels (92.5V) and your battery, which means your solar charge controller will have to drop the output voltage, thus augmenting the current: ~10.8A x 92.5 / 21V = ~ 47A
You should buy a 60A or higher controller to give it some rest.
Then 60A fuse (47A x1.25) for solar charge controller to battery + 6AWG or 4AWG gage wire.

3) Your battery-to-inverter fuse seems oversized (or is that a shunt?). 1500W continuous / 21v = 71 Amps x 1.25 = 90A
You could get yourself a 100A fuse! Also 2/0 cable would be safer, but 1/0 seems fine.

Glad to help!
Thank you! Thats why you guys are the pros. I will do exactly as you advise.
 
Thank you! Thats why you guys are the pros. I will do exactly as you advise.
I disagree with #2 and not everyone's advice on here is pro plus mistakes are made so hold on.
Your 40A Epever BN is fine for your 1000 watts panels at 24V
Have you already bought all those 10 100 watt panels, SCC and batteries?

Where are you installing the panels and this system? House or RV or?
 
Hi kenkoh,
1) The solar panel array is wired properly as far as I can tell. Cable gage seems fine as well.

2) The solar controller's amperage rating is insufficient! As your batteries can go down as low as 10.5V each (together 21v) there is a huge voltage difference between the solar panels (92.5V) and your battery, which means your solar charge controller will have to drop the output voltage, thus augmenting the current: ~10.8A x 92.5 / 21V = ~ 47A
You should buy a 60A or higher controller to give it some rest.
Then 60A fuse (47A x1.25) for solar charge controller to battery + 6AWG or 4AWG gage wire.

3) Your battery-to-inverter fuse seems oversized (or is that a shunt?). 1500W continuous / 21v = 71 Amps x 1.25 = 90A
You could get yourself a 100A fuse! Also 2/0 cable would be safer, but 1/0 seems fine.

Glad to help!
Like this?
 

Attachments

  • 60A-24V-1000W.jpg
    60A-24V-1000W.jpg
    76.5 KB · Views: 22
I disagree with #2 and not everyone's advice on here is pro plus mistakes are made so hold on.
Your 40A Epever BN is fine for your 1000 watts panels at 24V
Have you already bought all those 10 100 watt panels, SCC and batteries?

Where are you installing the panels and this system? House or RV or?
No I haven't bought anything yet. Install on a off grid cabin. So is the math wrong?
 
Yeah, those victrons can handle a bit more just fine. Check out the data sheet:
FireShot Capture 1002 -  - www.victronenergy.com.png
1000W for the 35A at 24V is ok. And lifepo4 is much higher than 10.8 for 98% of the discharge curve. So you will never need that many amps. Even if you did, the controller can handle it. You can overpanel victron controllers.

Yeah, the fuse is oversized. 52A is for 125%, so 60A is a good starting point. Unless you have massive surge etc. I would try a 60A fuse first.
 
Yeah, those victrons can handle a bit more just fine. Check out the data sheet:
View attachment 37204
1000W for the 35A at 24V is ok. And lifepo4 is much higher than 10.8 for 98% of the discharge curve. So you will never need that many amps. Even if you did, the controller can handle it. You can overpanel victron controller.
The OP choice of SCC is an Epever BN 40A for 1000 watts panels into a 24V LFP battery which was fine.
Then he was told to use a more expensive Victron plus bumping the amps up from 40A to 60A which is not needed.
 
I'll muddy it a little more.

Why 10X expensive 100W panels when you can buy bigger panels for less $/W? Why not 4X 250W panels? I just bought 4X 285W for $280 from SanTan Solar.

Has this system been designed based on:

1) Available solar for the location?
2) Energy audit?
 
I'll muddy it a little more.

Why 10X expensive 100W panels when you can buy bigger panels for less $/W? Why not 4X 250W panels? I just bought 4X 285W for $280 from SanTan Solar.

Has this system been designed based on:

1) Available solar for the location?
2) Energy audit?
Yes I can do that I wanted to check with yall my series parallel wiring as it's my first build and if an in-line fuse is needed. Do you know the voc for those 285w panels? I want to leave 25-30% headroom for the cold.
 
Back
Top