Need help sizing charge controller

[Giuseppe Hardblast]

I got 3 commercial panels that are 300w each.
They are 40v 9.5a

I have a 12v battery bank
I have a 30a viewstar pwm controller

Now am I right by saying 900w÷12v= 75a

So I need a 75a controller for these panels
 Or if I make my battery bank 24v I need a 37.5a(40a) controller

So my pwm controller is not going to work with these panels. I need either 80a or 40a with 24v bank.

Correct?

 

[Elbear1]

Correct you definitely dont want pwm with 40v panels. Get an MPPT. 80A will be good.

Id get something like this if youre on a budget.

https://www.amazon.com/EPEVER-Contr...aWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl&th=1

 

[Elbear1]

IDK what batteries you have but you cannot charge FLA's faster than about C6. If youre putting out 60A you need at least 300A of battery to accept that safely. AGM or lithium you need not worry.

 

[Giuseppe Hardblast]

I have 2 battleborn lithiums. I have 500w renogy 12v panels. It's just not topping my batteries off at the end of the day. Especially if there is overcast I need more power

 

[Elbear1]

If you can afford those maybe splurge on a victron controller.

 

[Giuseppe Hardblast]

I'm not sure why you recommended a 60a controller. I think I am going to need 80

 

[Giuseppe Hardblast]

If you can afford those maybe splurge on a victron controller.

I don't really need the Bluetooth and all the extra stuff. Just need something that works with a screen. And I spent all my disposable income on the batleborn. Budget friendly options take priority.

 

[Giuseppe Hardblast]

Looks like this is my best option

https://www.amazon.com/EPEVER-Contr...t&qid=1568348449&s=gateway&sr=8-25&th=1&psc=1

 

[Elbear1]

The victron is more than just bluetooth. Which you can get in renogy rover controllers for cheap. Just fyi

 

[Elbear1]

I'm not sure why you recommended a 60a controller. I think I am going to need 80

I didnt. I said an 80A. I referenced 60a charge rate because thats about what id expect from 3 x 300w panels.

 

[Giuseppe Hardblast]

Why recommend victtron?

 

[highdesertranger]

Victron has a good reputation for quality products, so does Morning Star. highdesertranger