Adding 600w of solar... am I doing this correctly?

[One Awesome Inch]

Hey guys...

Wondering if I can get your opinion on this...

This is what I am trying to do...
Two 300w panels wired in parallel
Equals 24v into the controller
Rover 40a controller manual says 1040w @ 24v
12v out of the controller and into the fuse panel
Have I got that right? Or do I need a second controller? Thank you.

Here are the specs
https://photos.app.goo.gl/Fdc94bsMNwUG2CMu8

 

[highdesertranger]

we don't know the specs of your panels. we need more info.

are you assuming that wired in parallel doubles the voltage? in parallel the voltage stays the same. in series doubles the voltage.

the 12v out of the controller should go to your battery not the fuse box. the fuse box then attaches to the battery.

highdesertranger

 

[Tom_M]

300 watt panels are usually 24 volt. If that's the case, connecting in parallel is fine. Running the controller output to the fuse panel is okay as long as you are connecting to a line that goes direct to your batteries. Best to have a fuse in this line.

 

[One Awesome Inch]

Specs

Maximum power voltage. .. 32.90v
Maximum power current. ... 9.12A
Open circuit voltage. ... 39.70v
Short circuit current. .. 9.57a

I'm told these panels are a nominal 24v

 

[highdesertranger]

I am not sure what you mean by a nominal 24v panel? if they mean those panels can charge a 24v system that's true but they are not 24v panels. the voltage into the controller is going to be closer to 32v then 24v. what are you running a 12v or 24v system? it really doesn't matter because those panels will work fine for both on that controller. just make sure to connect the controller to the battery and not the fuse panel. highdesertranger

 

[ByeBye]

just make sure to connect the controller to the battery and not the fuse panel.  highdesertranger

Mike, maybe I'm misunderstanding what you're saying but Renogy manual says to use a 40 amp fuse between controller and battery on the Rover 40.

 

[highdesertranger]

ok my bad but the original poster said,

"12v out of the controller and into the fuse panel "

I thought they meant the fuse distribution panel and I got crossed up between theirs and yours. sorry about that.

highdesertranger

 

[Gypsy Freedom]

Hey guys...


Rover 40a controller manual says 1040w @ 24v
12v out of the controller and into the fuse panel
Have I got that right? Or do I need a second controller? Thank you.

Here are the specs
https://photos.app.goo.gl/Fdc94bsMNwUG2CMu8

where the manual says 1040 watts @ 24v. they are referring to a 24 volt battery bank/system. all charge controller amp ratings are the output amps so 40 amps on a 24v system will be 2 times the power (watts) as the same amps on a 12v system

now technically, 600 watts could produce more than 40 amps. for example if the batteries are low like 11 volts at mid day with good sun high in the sky and you were getting close to the full 300 watts from each panel. 600 watts divided by 11 volts is almost 55 amps. on good sunny days you can get full rated power for short times. i have recorded 115% of rated output with flat mounted panels in tillamook oregon in july several days in a row. it was only for short times so it can happen. but most of the time, by the time the sun is high enough to get full power from the panels the batteries voltage has come up considerably. for example. if the batteries have come up to 14.5v then full 600 watts will only be about  41.5 amps and if the batteries have hit the absorb point, the amps could be considerably lower. so while it is possible for your panels to put out more than the 40 amps the controller is rated for. it is not the normal. for example, right now i have a 435 watt panel on my minivan. i generally see a peak watts output between 250-300 watts. this is because by the time the sun is high and the panels are making the most they can. the controller is already tapering off the current in the absorb phase. the question you want to get answered about your controller is "what happens if i exceed the rated amperage?" some controllers just clip or ignore the extra and keep right on trucking. others will fault and shut down, and others yet will get damaged. once you know how your controller reacts to an over current situation. then you can weigh the risks and decide if a second controller is warranted