One of the most exciting advantages the Verizon iPhone 4 has over its AT&T counterpart is its ability to become a mobile hot spot. A mobile hot spot allows several devices to connect to it via Wi-Fi and then uses a cellular signal to connect those devices to the Internet. Essentially the hot spot becomes a wireless router.
I was curious about the strain something like this would have on the iPhone 4's battery, so I decided to run a little test. I turned on the iPhone 4's hot spot and then connected a Wi-Fi-only iPad to its network. I then streamed a movie through Netflix ("Macbeth"; the Patrick Stewart version, which is surprisingly ambitious, by the way), until the battery on the iPhone 4 died. The movie is only about 2.5 hours, so periodically I'd have to scrub it back toward the beginning.
For comparison, I used the T-Mobile MyTouch 4G, as it was the only hot-spot-capable phone available for testing at the time. I used the same methodology to kill the MyTouch 4G's battery life.
To provide context, I'm also including how long each phone's battery took to die while playing a movie. The movie, "Toy Story 3," on the iPhone 4 was optimized for iPhone 4, whereas "Toy Story 3" on the MyTouch 4G was encoded at 720p.
|Tests||Apple iPhone 4 (Verizon Wireless)||T-Mobile MyTouch 4G|
|Hot-spot battery life (in hours)||5.2||5.1|
|Video battery life (in hours)||10.3||6.6|
While each phone lasted a bit over 5 hours as hot spots, as video players, things were a little different. The iPhone 4 lasted more than 10 hours, whereas the MyTouch 4G lasted only 6.6 hours. This is an interesting difference that could have to do with the type of videos used by each phone.
I simply felt that each phone should be tested with the best quality video it's capable of displaying. Each test was run up to three times, with the final results an average of the best two times, as long as they were within 5 percent of each other.
During the video battery test, each phone was placed in airplane mode, with their respective brightnesses adjusted between 140 and 150 candelas per square meters (cd/m2).
While running as hot spots, the phone screens were set to shut off after a minute and were never turned on until after their batteries died.
We should also note that we noticed a difference in quality between the two phones while streaming "Macbeth" on the iPad. When using the iPhone 4 as a hotspot, the movie looked to display at Netflix's lowest quality setting. Netflix is known to dial back the visual quality of its streaming signal depending on network traffic or the amount of devices steaming off the network and the speed of your connection.
When streaming using the MyTouch 4G as the hotspot, the image on the iPad was much clearer. I've attempted to illustrate that difference using a couple of pics.
The iPhone 4's battery is able to put an impressive foot forward if watching movies on the device itself, lasting about 35 percent longer than the MyTouch 4G in video playback battery life.
In hot-spot mode, while the iPhone 4 and MyTouch 4G's batteries lasted about the same duration, the MyTouch 4G will make for a more pleasant experience if streaming movies to another device. The Verizon iPhone 4's 3G signal just isn't fast enough (at least in San Francisco) to deliver a consistently high-quality streaming video image. At least not through Netflix.
The Verizon iPhone 4's hot spot worked as expected, just don't expect it to deliver a superfast speed.