I’ll be using my iPhone as a cycle computer, which means GPS. I use the camera, likely shoot some video and who knows what else. It is so capable. My reading [warnings] tell me of its short battery life. Maybe so, but not for me. As a user of an Edge 305 [which has failed to get me through a century or two], I now use an external power source. For the Edge, I’ve used a Li-Ion USB external battery [I have 3 of these] and a simple 2AA battery USB external battery. They both work and have worked on two double-centuries for me.
Testing, my iPhone, I’m on my 3rd day of running it on my external Li-Ion battery—not a lot of drain, in that I using its ipod function and occasionally use the browser or other apps. My point here is that the Li-Ion connected to the iPhone will probably get me through any cycling event I’ll participate in. In my testing, the 3GS has yet to go to its internal battery.
YMMV; but, from my perspective, if you are doing "endurance/extended" events use external power, rather that expect the iPhone’s internal battery to get you to the end.
My $0.02, FWIW.
Works for me!
Last Monday, 07/20, I purchased my iPhone 3GS [Luv It!]. Shortly there after I dropped my principal Garmin Edge 305—not a problem its been dropped before. It has even fallen from the handle bars of my DF to the pavement—never a problem. It has always continued to work. Well, the drop after receiving my iPhone broke the LCD display, but not so severely that the LCD bled. I did not know it was broken until I prepared to ride my RANS Crank Forward [Faye] yesterday.
Fortunately, I have a backup 305 [which is more sensitive to road vibrations]. Put it in action and did my short neighborhood ride [needed to deliver a draft of a print job]. At least it did not go off.
Galled Garmin to replace Edge #1—no problem. For a very reasonable cost I get a refurbished 305—shipping included. I pay to ship the unit to them. The deal was so good, I decided to replace both 305s. Now, I’m Edgeless; but, I have my iPhone with its cycling apps. I may get to check on on a longer ride today. I have to say my Edge 305 support for Garmin has been excellent. Garmin Connect is another issue.
The question now is: should I keep both Garmin Edge 305s and use them with my iPhone? As I see it now, I’ll likely use the Edge in my LWB recumbent and trike and the 305 only on my low racer and DFs. What would you do?