Solar voltage help...

Some controllers have a feature that clips the amps so they cannot pass through any more than spec. The bumph for the controller should say if it does that or not. Seems many/most MPPT are like that.

Many PWMs will pass through the amps and will overheat if the amps stay over very long (how long? you have to find out the hard way)

Standard advice (might be US NEC related) is 20% margin above the 25C temp spec for when panel does better than rated (in the cold or when getting edge of cloud effect) and that applies to the controller's amps size AND to the size of the fuse between battery and controller on the pos wire.

My Sharp panel user's manual says the same thing, warning that the panel can exceed its ratings at times.

I did not invent the 20% margin idea :)

BFL13 wrote:
... you need a controller with 20% margin over panel rated Isc...
IGNORE all these people saying you should have a 10a controller.

Morningstar says that their 10A unit doesn't need 20% margin. Alright, ignore them :)...

EsoxLucius wrote:
14.4 volts in bulk and absorption and 13.2 volts in float would not properly charge and maintain my batteries. Hence, the inexpensive controllers won't always give one what is needed. Be nice to your batteries!

Yes. Inexpensive controllers - even from a brand name - will almost never give one what is needed. Non-adjustable setpoints and temp-comp is 2 reasons why, and there are other reasons as well. Cheaper clones of inexpensive brand units may also have reliability issues - their circuit boards are not sealed properly against elements, and all the components are hit and miss, higher possibility that something fails soon or won't work from the day one.

The concept that expensive controllers are expensive only on retail end, is a myth. Expensive controllers (= known brand AND loaded with features) means more investment in R&D, manufacturing and QC.

If controller is just one of toys, than this all doesn't matter. I'm living seasonally in off-grid rig, and need to be able to rely on solar, so units without necessary features or that are not reliable will simply not work for me.

RJsfishin wrote:
Except for the equalize, that's exactly what my CMP does, only for 12 bucks

One thing I like about the morningstar over the CMP is that the CMP has no weather resistance at all while the morning star does.

Series would need a jumper not connected to the controller.

smkettner wrote:
Looks parallel to me.

cuz the red goes to red and black to black, right?

Looks parallel to me.

That's how it came.

Is that how it came wire from the factory? ain't that in series?

Looks too easy to connect the battery second.
You need one of those disconnects on the panel connection.

NinerBikes wrote:

OregonTRX4 wrote:
I just connected my solar kit (160w cmp12 controller)and the voltage while connected to the rv batteries reads 16.55v. Is this normal or too high? Sorry but im new to this.

Please take a picture of the wiring you are using at the back end of the panel, where the solar controller is located, and post it up here.

As requested.