My Beginnger Setup

[RandyF]

I'm building a small system that will handle about 120w of continuous AC load in the house.

I've got 2 x 450W LONGI Panels:


And want to get the 60A MPPT Renogy Charge Controller 12-48V (Max PV input 150VDC, Max PV Power input only 800w for 12V, 1600w using 24V) with the Renogy 2000w Inverter, using 2 x 100ah batteries.
It looks like, from the Inverter, that I need to configure the Panels in Series.

Would the panels need a fuse/breaker?
Should I get a 100amp fuse for each battery?

Thanks for your help.

 

[Rednecktek]

Are you doing a 12v or 24v inverter? That will determine the fuse size for the batteries and inverter. 2000w / 12v × 1.25 = 200a fuse. 2000w / 24v × 1.25 = 100a fuse.

Either way you could run series OR parallel as your individual panels should produce plenty of voltage. You won't need fuses for your panels until you get 3 parallel strings involved.

 

[MisterSandals]

And want to get the 60A MPPT Renogy Charge Controller 12-48V (Max PV input 150VDC, Max PV Power input only 800w for 12V, 1600w using 24V) with the Renogy 2000w Inverter, using 2 x 100ah batteries.

Is there a reason you chose Renody SCC and inverter?
Pure sine wave inverter i hope?
What batteries? Lithium or ?? Lead acid batterie are 50% usable so that will matter for sizing purposes.

Should I get a 100amp fuse for each battery?

Are you expecting to draw 100A from each battery or are you basing this off the 100Ah capacity (mistakenly)?

 

[RandyF]

Thanks. The Renogy 2000w inverter is a 12V. Does that mean I can't run the 2 batteries as a 24v setup?

MisterSandals: Yes their stuff is Pure sine wave. Using 2 x 12V 100ah, or 1280wh batteries from Lisuateli. Looks like I don't need a fuse for these since the 100A BMS has all of the features I need.
Renogy products are easy to get here in Canada. I wish sunlight was just as easy to get.

 

[Rednecktek]

Thanks. The Renogy 2000w inverter is a 12V. Does that mean I can't run the 2 batteries as a 24v setup?

That is indeed what it means. If you feed 24v into a 12v inverter you release the magic orange smoke.

You just have to put your batteries in parallel to keep the system at 12v. Each of your batteries will do half the work which will max out your batteries if you ever try to fully load up that inverter.

MisterSandals: Yes their stuff is Pure sine wave. Using 2 x 12V 100ah, or 1280wh batteries from Lisuateli. Looks like I don't need a fuse for these since the 100A BMS has all of the features I need.

The BMS is there to protect the battery, fuses/breakers are there to protect the wires and inverter. If you are relying on your BMS to protect everything you're just asking for trouble. At the very least get a decent quality DC breaker involved in there.

Renogy products are easy to get here in Canada. I wish sunlight was just as easy to get.

Yeah, especially in the Northwest where we never see the sun.

 

[RandyF]

That is indeed what it means. If you feed 24v into a 12v inverter you release the magic orange smoke.

You just have to put your batteries in parallel to keep the system at 12v. Each of your batteries will do half the work which will max out your batteries if you ever try to fully load up that inverter.


The BMS is there to protect the battery, fuses/breakers are there to protect the wires and inverter. If you are relying on your BMS to protect everything you're just asking for trouble. At the very least get a decent quality DC breaker involved in there.

Yeah, especially in the Northwest where we never see the sun.

Excellent, thanks for this. I'm still confused about what capacity of fuses to get. Some used a 2000w inverted and I think they used a 175 or 200amp fuse for it.

 

[Rednecktek]

The math says 208.3a which doesn't exist. You could go with a 225a and make sure your wires are large enough for that current OR go with a 200a and just not run your inverter at full load for very long. Like 1900w max or so.

 

[RandyF]

The math says 208.3a which doesn't exist. You could go with a 225a and make sure your wires are large enough for that current OR go with a 200a and just not run your inverter at full load for very long. Like 1900w max or so.

Thanks, I can't see it ever getting near 2000 so I'll get a 200a fuse.