When you see that “looks like an Apple charger” somewhere at an unbelievably low price, your wallet might be happy, but your iPhone might not be. Ken Shirriff did a comprehensive review of device chargers and while he found that Apple chargers might not be the best around—counterfeit ones are certainly a much, much bigger problem.

Here’s what Ken has to say:

Counterfeit chargers pose a safety hazard as well as a hazard to your phone. You can buy a charger that looks just like an Apple charger for about $2, but the charger is nothing like an Apple charger internally. The power is extremely bad quality (as I will show below). But more importantly, these chargers ignore safety standards. Since chargers have hundreds of volts internally, there’s a big risk if a charger doesn’t have proper insulation. You’re putting your phone, and more importantly yourself, at risk if you use one of these chargers. I did a teardown of a counterfeit charger, which shows the differences in detail.

[From Ken Shirriff’s blog: A dozen USB chargers in the lab: Apple is very good, but not quite the best]

Yikes. And here is one of the photos from his post on what can happen:

Yeah, that’s charing. Like flames, magic blue smoke, serious badness. Ken’s post is amazingly detailed—I still haven’t finished digesting it—but if you skim down to the charts with info on the current passing through the various chargers, you’ll see immediately how freakin’ bad counterfeit chargers are for your devices. Just…wow.

Lesson of the day: yes, saving a buck is awesome, but frying your iPhone (or your house) with a cheap charger is most certainly not.

Hat tip: TUAW.