How Do I Evalute Good Product from Bad (in China?)

[jklunder]

Hi Everyone,

I am helping someone who builds GreenHouses. He is abroad and I am in China.

My goal is to help him by evaluating the physical products in China. I know they manufacturing so much here; but, it's hard to know if it's good or not.

Are there any field guides that can tell me what are the right questions to ask, and what to inspect?

Thanks

[paris401]

Hi Everyone,

I am helping someone who builds GreenHouses. He is abroad and I am in China.

My goal is to help him by evaluating the physical products in China. I know they manufacturing so much here; but, it's hard to know if it's good or not.

Are there any field guides that can tell me what are the right questions to ask, and what to inspect?

Thanks

the list of lousy Chinese products is long... the list of good products is... short... actually the list is blank...

[Logan005]

a charge controller protects your very expensive and very heavy battery bank, If you cheap out, expect to replace your battery bank sooner rather than later. I would not recommend a Cheap Chinese CC as it will likely cost you much more than you save in the end. stick with known names, Outback, midnight, xantrx and so on. if it has no name don't bother. If it's less than 100 bucks and claims to be MPPT don't bother.

[jflorey2]

Are there any field guides that can tell me what are the right questions to ask, and what to inspect?

Is he an electrical engineer? If so you can test:
-accuracy of setpoints
-stability of output under various complex loading conditions
-noise on output and input (differential and common)
-noise on internal signals (should be well within signal threshold limits)
-ringing/overshoot/overcurrents on switching nodes and at transformer/inductor leads

You can also inspect for:
-good thermal design (proper heatsinking and thermal paths)
-good electrical design (decoupling caps, proper routing, proper isolation)
-good board design (creepage/clearances observed, proper passivation, solder mask or conformal coating)
-good mechanical design (strain relief, maintainability, design for vibe/shock)

I'd expect a good inspection of an MPPT charge controller would take about five days at a well equipped lab.

[Sunking]

What list? It is Chi-Com, 90% of it is junk. Most of it FRAUD.

[J.P.M.]

What types of products ? appliances, building materials, what ??