20a charge controller

[joeExotic]

I have a 20a charge controller. Currently I have 2 100w solar panel right now. I want to add 2 more for a total of 400w. Will my 20a charge controller be ok with 4 100w panels? I don't want to damage the charge controller. My battery is 125ah agm. I want to stick to 12v not 24

 

[joeExotic]

I know I can add another 100w panel and that will be fine but if I have a total of 4 100w panels with my set up will that be fine as well or is that damaging?

 

[ScoTTyBEEE]

Depends on the charge controller.

 

[joeExotic]

It's mppt renogy 20a charge controller

 

[ScoTTyBEEE]

260W max

 

[joeExotic]

Yeah I get that but with my 2 100w panels now the most I've seen is 150w that I'm reading. I figure with another 200w total of 400 that sometimes I'll get 300w coming in and I'm asking will that damage the charge controller or will the charge controller be fine and just use the 260 that it can get and dump the rest. I don't want to damage the charge controller or the 125ah battery

 

[ScoTTyBEEE]

The charge controller will likely throw an error and remain that way until the power goes below 260w. Read the manual to see if it does what you want but it doesn't look like it to me.

 

[joeExotic]

So if the error comes on will the system be working properly? Does it mean it is at max capacity? And no damage to charge controller

 

[ScoTTyBEEE]

I've only skimmed the manual, go through it all and you'll have your answer.

 

[joeExotic]

I want to max out the 260w that the charge controllercan handle and feel that 300w panels won't max it out and 400w panels will but want to make sure that with 400w panels the charge controller and 125ah battery won't get damaged

 

[ScoTTyBEEE]

You made that quite clear in the initial post and I'm suggesting you read the manual to find your answer. Here's a link to it.

Rover Li 20 Amp MPPT Solar Charge Controller

Renogy solar charge controller works with Gel, Flooded, Sealed, and Lithium batteries. The 20A MPPT charge controller is used for 12V 24V solar systems.

uk.renogy.com

For what it's worth I had a 310w solar panel on a charge controller and rarely saw over 20amps

 

[joeExotic]

I have the commander not rover

 

[ScoTTyBEEE]

Read the manual for that version then.

 

[Bob142]

According to the Commmander manual (see pages 10-11) you will be fine with 400W. It states you can have up to 780W of panels. I highly recommend you read through the entire manual and follow all instructions and safety precautions.

From page 10:

From page 11:

 

[joeExotic]

Wow thanks that's helpful. If i go for the 400w total panel with the 20a charge controller will my 125ah battery be ok?

 

[joeExotic]

I just got off the phone with the supervising tech support at Renogy and he told me that with 400w going into a 20a mppt charge controller (commander) that it will burn out the charge controller. Can somebody help to clarify this? I wanted to put four 100w panels in parallel and have them face in different directions so that it will catch the sun from morning until sunset. So I figured that not all four panels will be getting sun all at once. Please help.

 

[NoSmokeYet]

Well that's a interesting idea. Hope it works out for ya.

 

[joeExotic]

The renogy guy said three 100 w panels would be fine for the 20 amp charge controller but not four 100w panels. BUT what if I face one panel to catch the morning sun then another to catch the afternoon sun and face the last two panels to catch the evening sun? Not all four panels will be getting sun at the same time. Does this sound like it will work and not burn out the 20 amp charge controller

 

[Forbisher]

The renogy guy said three 100 w panels would be fine for the 20 amp charge controller but not four 100w panels. BUT what if I face one panel to catch the morning sun then another to catch the afternoon sun and face the last two panels to catch the evening sun? Not all four panels will be getting sun at the same time. Does this sound like it will work and not burn out the 20 amp charge controller

I am guessing that you have Renogy 100 watt panels?
How many Isc amps are they? What about 4 panels in parallel?
What is the Voc open circuit voltage?

Your MPPT SCC has a 147 volt max.
Where did you get this idea of facing 4 panels in different directions?
The afternoon sun is the strongest.

 

[joeExotic]

I have renogy 100w panels mono. I do want to put them in parallel. I qant to chase the sun throughout the day I I figured that i can face all four panels in 3 different directions (left, up, and right)