MPPT Controller for Van

[LDVV]

I thought I had a grasp of this basic stuff, but apparently not.

I want to put a 315w 10A panel on my van (12v system). I'd planned on putting this in as the Charge Controller:

***
Epever solar charge controller 20A XTRA2210N
Tracer 2210AN MPPT Charge Controller
12V / 24V DC Auto
Max Input Power:12V @ 520W | 24V @ 1040W
Max.PV open circuit voltage:100VDC (92V at 25 temperature)
Battery type: lead-acid (Gel, Sealed, Flooded) and Lithium
Battery voltage range: 9V~32V C
***

However, I've been told the the maximum power that I'll be able to get, from the panels, through this device is 120w - 'we recommend you get the 30A version'.

What am I missing here? I thought I had the basic specs covered...

 

[Browneye]

You're probably fine, 315w divided by 13V is 24A, but if it's mounted flat on your roof you'll never see full production anyway. And even you do you might clip a few amps mid day, but pick them up early and late anyway.

I have a Xtra3210N and really like it - 430W of panels, I rarely see more than 275W out of them. Maybe when my battery gets down and over summer I'll see more.

The 2210 can be over-paneled up to 390 watts per the manual.

 

[rmaddy]

I can’t imagine why someone said a max of 120W on a 20A controller. 20A x 12V is 240W. When the battery is fuller it can support about 280W.

A flat mounted 315W panel will rarely get 280W.

The 20A controller will be fine 90% (or more) of the time. A 30A controller will let you take full advantage of the panel 100% of the time.

 

[Biker44]

I'm running 2 x 175watt panels (wired in series, so nominal 24volts) = 350 watts on a 10 amp Epever XTRA 1210N.
Its just within spec according to the instructions and seems to work fine.

 

[Browneye]

If they're 24Voc in series they should put out double that. I get about 48V from my two 215's into a 20A Xtra.
Also works fine. I think parallel or series would be fine, the higher voltage is a little more efficient across the 10g solar wire. My leads are 25' long.