Hey, glad to have helped solve your problem. And thanks for your kind remarks. And Yes, you should switch back to the approved actual Apple chargers. I think that using any substitutes will void your warranties.
Plus since you definitely are pretty tech savvy, and i can come in from the electrical side of this issue ( as you discerned)
I thought you might find the following of some interest.
if you knew all of the major differences between well made Apple chargers, and their cheaper substitutes, regarding the actual quality of the converted electric power that they output, you would never use a substitute again.
There are different levels of purity of the electrical wave form output when it comes to any inverter/charger.
Con Ed power when hooked up to an oscillator will always be a flowing sine wave. Any major electrical utility company will produce this level of purity.
This is called a True Sine Wave Power output. You get this type of problem a lot when hooking up stand alone solar power systems.
People think that all solar Inverters output the same type of quality electricity. But that isn't the case. There are cheaper inverters called modified sine wave inverters. Hooked up to an oscillator they show up as a sawtooth line. With 90 degree angles and short saw tooth like non-wave readings. These substitutes are always included in all cheaper solar system sets.
And they will corrupt and eventually destroy any and all of your equipment hooked up to them.
So for solar systems, you would need to buy only True Sine wave power Inverters. It is the same for chargers. When you buy those non Apple Chargers you wouldn't think to hook up an Apple one or a substitute ones output cable to an oscillator, but if ya did, you would see pretty much the same differences in their outputs as with solar inverters, which is exactly the point that I am trying to convey.
Since you are definitely Tech Savvy, ( which I am not so versed in ) I figure you would understand this really quickly and hopefully it will help you in the future.
Also if the 12w USB Power Adapter that you mentioned is the one that Apple issues with their Mini IPads, then yes definitely use it. But in electrical terms it is the Voltage that must match up pretty close! That is the most important.
An IPad like IPhones or any other smartphone or pad, uses industry standard 5 volts. Wattage comes next. While wattage can vary, voltage can't. So you can use the 5 volt 5 watt apple charger even on your mini, it will just take longer to charge it but if they sell it with the 12 watt then use that one too. I usually alternate between the 5 watt and the 10 watt for my IPad 2. It's good for the battery to slow charge it occasionally. Fast charging (above what Apple provides per device) can lead to lower battery functioning and capacity though.
So I wrote another thorough reply!! I am working on getting them down to size.... One of these days. Cheers!