What are the differences in a T4 connector and a MC4?

I was concerned about using the MC4 connectors until I tried them. They are easy enough to unplug w/o the tool.

It's common to use 2 contact SAE connectors (they're like the common 4 wire flat trailer connectors). You can find them with 12 ga wire, which should be good for a couple of 100W panels, albeit with some loss. It's pretty common to find them pre-installed on RVs as part of a "solar ready" package. But, they're usually just wired straight to the battery, and the portable panels are expected to have their own controller.

Since we're talking about solar panel connectors, is there something out there that's designed to be connected/disconnected more frequently?

The mc4s (or equiv) don't seem to be designed for it. I've got the tool to disconnect but still ...

Thinking about a portable solar system. Perhaps just regular 120VAC connectors? Or something a bit more waterproof?

MC4 is a proprietary connector made by the company Multi-Contact (now Staubli). T4/H4 and others use the same form factor. Because the MC4 is proprietary, there is no industry spec that all the variants are built to which guarantees compatibility and interoperability. They're all based off the original MC4. But Multi-Contact does what they can to keep the market to themselves, including dire warnings that the earth will be riven asunder and death and destruction will result if they're interconnected with competitors products.

I wouldn't worry about T4/H4/MC4 FUD at all for an RV scale system. For a large fixed system putting hundreds of volts and tens of amps through them, sure - stick to one brand. But if you're putting a few panels on an RV, and they come with "MC4" type connectors already installed, I wouldn't worry about finding connectors from the same manufacturer to complete the system. They're all made to be interoperable, despite the dire warnings.

Not sure why Almot thinks Amphenol is German - their original name was American Phenol, and they're US (they do manufacture worldwide). Staubli is Swiss. T4s are made by Tlian, a Chinese subsidiary of Canada Solar.

Yep, "comparable" :)

T4 must be the product of CS Chinese partners. There is also H4 by Amphenol company in Germany, and if you check Ebay, you'll also find "PV4 MC4" from nameless and countless Chinese factories. Unlike MC4, none of those is UL approved, and neither is mating MC4 with others. Though Amphenol took pains to test according TUV standards and submitted reports saying that H4 are fully compatible with MC4.

I guess you can plug it in.
"Better"? Who knows... Wouldn't bet my life on it.

Edit - PS:
it's always a good idea to tuck the connectors under the panel, away from rain and UV, be it original or "comparable".

Data sheet says MC4 or "MC4 comparable."

https://d1819pwkf4ncw.cloudfront.net/files/documents/datasheetquartechcs6x-pen-259377.pdf

As a look alike, do they plug into one another? I have Canadian Solar panels with T4 connectors coming and have all my cables with MC4 connectors that I got from Unlimited Solar.

howardwheeler wrote:

Is one better than the other or more suitable for particular applications?

I doubt than one is really "better" than another. MC4 is older and is an industry standard, UL approved. T4 is a look-alike from Canadian Solar subsidiary.