Is 40 amp Charge Controller okay for 500 watts solar?

[Confetti]

Newbie here... I want to follow Will’s 400 watt DIY video pretty much exactly.
But I want to get two 250 watt panels on my camper van. Do I need to get a 50 amp or bigger charge controller? Or can I stick with the 40 amp that he shows in the video?

I’ve ordered a 2000 watt pure sine inverter.

With the 500 watts of solar, does that change all the other components that he recommends in the video? What else has to change? I don’t want to confuse myself, LoL.

 

[Bud Martin]

Not sure which exact video you are referring to.
What kind of load and how much loads are you going to use with the system? You need to do power budget first and also how many days you plan to run the system without any recharging source then you can figure out what you need to get to build the system to fit your needs, then you can figure out what you need below.
1) What is the system Voltage do you want to use? 12V? 24V?
2) What type of batteries chemistires are you going get?
3) What is SCC (Solar Charger Controller) do you have in mind?
4) What type of inverter did you order? High Frequency type? Low frequency type for starting high inrush current load?
5) Plan for future expansion?
6) Etc.
I'm sure others will have added questions as well.

 

[Forbisher]

But I want to get two 250 watt panels on my camper van. Do I need to get a 50 amp or bigger charge controller? Or can I stick with the 40 amp that he shows in the video?

I’ve ordered a 2000 watt pure sine inverter.

With the 500 watts of solar, does that change all the other components that he recommends in the video? What else has to change? I don’t want to confuse myself, LoL.

Welcome to the forum.

500 watts panels into a 12V battery is about 40A so that size SCC is good and would not change anything.
50A is not needed unless you plan to add panels in the future.
50A x 12V is 600 watts.

You could parallel or series connect your two 250w panels.

 

[Confetti]

Not sure which exact video you are referring to.
What kind of load and how much loads are you going to use with the system? You need to do power budget first and also how many days you plan to run the system without any recharging source then you can figure out what you need to get to build the system to fit your needs, then you can figure out what you need below.
1) What is the system Voltage do you want to use? 12V? 24V?
2) What type of batteries chemistires are you going get?
3) What is SCC (Solar Charger Controller) do you have in mind?
4) What type of inverter did you order? High Frequency type? Low frequency type for starting high inrush current load?
5) Plan for future expansion?
6) Etc.
I'm sure others will have added questions as well.

This is Will’s 400 watt DIY video:

I’m going to follow it exactly.

 

[Confetti]

Welcome to the forum.

500 watts panels into a 12V battery is about 40A so that size SCC is good and would not change anything.
50A is not needed unless you plan to add panels in the future.
50A x 12V is 600 watts.

You could parallel or series connect your two 250w panels.

So,I can get the 40 amp charge controller that he recommends? Are all the other components that he mentions in the video are all still recommended? Current?

That’s why I was so thrilled when I watched this video. I was completely confident that I could do it! As long as I didn’t deviate or change anything, I can do it with minimal help.

I’m not planning on expanding. I can’t fit any more panels on my van roof anyway, LoL.

 

[iamrich]

I think the one listed in the details of the video above and the unit actually in the video are two different units, but either should work. A 250w panel is usually 30ish volts and 8ish amps, so if you series the two panels you get 60v and 8a (both well below the rated) or parallel 30v and 16a (also well below the rated). The Rich (no relations ) Solar version linked says it will handle 800 watts, but as mentioned you are only going to get 480watts of charging (40ax12v), but chances are you are not going to see a full 500w out of your panels anyway unless you park the van in a laboratory setting.

 

[brainfarth]

I'm curious about the controller. I have a battery tender on my two type 27 batteries because I've read other chargers that constantly trickle will eventually kill the batteries. Are those controllers smart enough to only top-off the batteries so I can leave it hooked up to the batteries 24/7?

 

[time2roll]

40 amp MPPT is fine. 30 amp is fine also even if it clips some peak power mid day.

 

[Confetti]

I'm curious about the controller. I have a battery tender on my two type 27 batteries because I've read other chargers that constantly trickle will eventually kill the batteries. Are those controllers smart enough to only top-off the batteries so I can leave it hooked up to the batteries 24/7?

I don’t know. But if it’s a controller that Will highly recommends, then I feel safe using it.
Watch his “400 watt DIY beginners solar” video for his explanation.

 

[Confetti]

Thanks everyone! Got the system installed, everything seems to be working perfectly.
Custom Unistrut roof rack over fiberglass high top roof. Two 250 watt used panels from SanTan Solar in Gilbert Arizona ($50 each).
2000 watt inverter, 40 amp SCC, 3 Battleborn batteries. Behind driver’s seat.

 

[nwillitts]

very cool.