Yootech

Can I leave the charger plugged in to power even when I’m not using it?

yes, you can

Is this Qi certified?

yes, good product

How many coils does the prudent have?

two

I plan to buy one, but will the metal plate for car mounts prevent the phone from charging completely?

I think the charger doesn’t work with the magnetic mount. You have to remove it to charge.

Will this charge a new iPad that has enabled for QI charging ?

maybe not, you can check on their description.

It works fine. but sometimes the charger turns off, what's wrong with it?

I have not had that problem. Maybe try another cable.

Serves for Samsung galaxy J7

No, for the reason that it does not have wireless charging capabilities.

My iPhone 7 plus doesn't have qi built in. I am using an aftermarket receiver case. Will this still work?

not sure, you can have a try

I purchase this product about 5 months ago and it initially worked great, but recently stopped charging fast. Has anyone else had this problem?

Have you changed a thicker case or a different wall charger?

How can I know it is fully charged?

when the battery up to 100%