Powermat iPhone 4 wireless charging kit
Cutting the cord
Review Powermat, the best-known purveyor of wireless charging systems, missed a chance by not getting its iPhone 4 inductive charging pack out sooner than it has. Antennagate highlighted the benefits of wrapping the newest iPhone in a case, and Powermate might have sold a fair few units on the back of it.
Powermat's iPhone 4 bundle: wireless charging out of the box
Fortunately, it has newly stoked fears concerning the resilience of the handset's glass  face and rear to call upon when the kit goes on sale early next month.
In addition to a case designed to link the iPhone 4 to one of Powermat's charging pads is a single-device charging tray. Unlike the regular pads, this one has raised edges. The tray gets its mains power from an AC adaptor smartly designed to make it easy to wrap the cord around it.
I should explain how Powermat's technology works. It uses magnetic induction to transmit power between two coils of wire - one in the charger, the other in the case - when both are sitting within the same magnetic field.
Fits together neatly
It works, too. Good alignment is essential, but the design of the pad ensures that even though, as with Powermat's multi-device charging pads, it gives a wee bleep when device and pad are ready to exchange power.
Case in point
Put your iPhone 4 in the case - the top sixth of the Powermat unit folds back so you can slide the handset in to latch onto the integrated dock connector in the base - and then put the case on the tray. Almost immediately, the iPhone screen lights up with the usual green battery image and the phones starts charging up.
The case makes inserting the iPhone 4 easy. It's a little more tricky to get out
If the process doesn't complete as quickly as it does when you use Apple's own AC adaptor, then there's still not a lot in it. Adopting Powermat charging doesn't mean putting up with longer waits for your iPhone to be topped up.
But that's not to say it's without other issues. Powermat's iPhone 4 is solid and well-made but it adds 6mm to the length of your iPhone and a little extra, noticeable weight.
As I say, the handset slots onto a dock connector within the case, and there are grille-covered gaps that line up the phone's speaker and microphone. Even so, on a number of occasions, callers complained that my voice was muffled.
The raised edges mean there's not much else you can charge on the tray
Powermat has fitted the end of the case with a micro USB port so you can sync up your handset - a cable is included - without having to first take it out of the case. Fine, but what about those of us who dock our phones into speaker units?
Because there's no pass-though dock connector on the case, while it will fit into a universal dock with the plastic adaptor removed, there's no point in doing so because of the connector incompatibility.
The charging case has micro USB for syncing, but that won't help you dock the phone to speakers
If you have to take the phone out of the case for music playback, you may as well leave it out and stick to cables for charging. Indeed, if the iPhone is the only handheld device you charge regularly, you may find it's drop-and-charge approach no more convenient than plugging the phone in in the usual way.
Apple's little adaptor is slightly more power efficient. I measured 4.5W when charging the iPhone 4 this way - the Powermat drew 6W.
Powermat's system really comes into its own if you have other stuff to charge too, but you'll have to pay extra for a bigger mat for that.
I like the idea of wireless charging, but there's no advantage to it - but some big downsides - if you have only one device to charge. Multi-handheld households will, however, appreciate having a single point to power up all their kit. ®
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