Battery performance on Wi-Fi enabled devices varies pretty wildly based on our experience, but the folks over at technologyreview.com think they finally know why. According to researchers over at the University of Texas, most Wi-Fi enabled access points don't properly implement the protocol designed to reduce the power drain on mobile devices. This makes performance somewhat inconsistent, but researchers think it's something that can be addressed going forward.
The power saving mode was designed to allow mobile devices to enter a "sleep" mode between packet requests, however most end up staying in a fully powered up state until the completion of the entire transfer. Depending on the size of the file, and the network latency, this can add a considerable amount of additional battery drain. Head researcher Eric Rozner concluded that "an HTC Tilt's total power consumption increases by threefold when using Wi-Fi". 3G data caps are likely to increase consumer dependence on Wi-Fi in the future, so clearly this is a problem that deserves a bit of attention.
We hope this is something the handset makers find a way to address given the relative ease of pushing updates to smartphone platforms, but if the problem is indeed with the access points, I wouldn't count on this unfortunate situation resolving itself anytime soon. Isn't this why we have the Wi-Fi Alliance? I guess they are still licking their wounds after arguing about 802.11n for seven years .