I suspect you're eligible for a brand new iPhone 5.

Check the following: https://www.apple.com/support/iphone5-battery/

Your battery us probably dead. Maybe get that checked?

For what it’s worth, my 5s gets about six hours of intense use. 50% brightness, Twitter, Safari, RSS reader, mix of WiFi and cell towers, mostly good reception. Five hours with only cell towers, average to good reception.

However, since the iPhones have such tiny batteries their battery use is also highly dependent on how you use your device. With something downloading (especially over LTE) I can practically see my battery draining and it gets quite hot.

Bigger devices with much larger batteries are a bit more sedate in their reactiveness to that, e.g. my iPad is much more constant in its battery usage. No matter what I do, it always gets nearly the same battery time. (Maybe because battery usage is much more dominated by the screen which has a constant battery use, so the other two big battery consuming components which are variable, radios and SoC, have a smaller difference in impact between being nearly idle and running at full tilt.)

They are using Wifi and pausing between page loads (so that fast phones don't load 4x as many pages and lose the test).

On Wifi 10 hours sounds closer to my experience than 1-2 hours.

My phone is 2.5 years old at this point. Maybe I've been losing battery capacity so gradually I've never noticed.

That would be amazing to have 13 hours of browsing with a new phone. (as reported in the article)

The iPhone 5 was only released 2 years ago (21 Sept 2012), yours can't possibly be 2.5 years old.

Ok, apparently I have a 4S. Maybe it's older than I thought.

I know someone with a 4S and the battery really struggles now especially when using GPS.

This happened to me. I bought a Mophie Juicepack for it and it solved the problem...by doubling the weight/volume of the phone.

Got an iPhone 6 on friday.

Yesterday I went on a 2.5 hour, 30 mile bike ride, and the iphone6 battery meter was essentially still at 100%. My 4s would have been well under 50%. Of course, the M8 is why, but after 3 years of recharging the 4s every night the battery was really starting to feel it.

Mine is the same age. Note I haven't measured but but hour plus browsing sessions have a fairly negligible impact on the battery so I'm confident it would at least reach about 5 hours (in percentage terms closer to 10 hours than 1-2).

When browsing on weak LTE the situation is different and 1-2 hours sounds very plausible. Maps/navigation can take big chunks out of the battery in a period of an hour or two and I need +60% before I set out on a 3 hour bike ride with Cyclemeter on.

Early iphone 5 units had a bad run of batteries. There is a free replacement program. Apple has a web site to check your serial number to see if your phone is afflicted. It made a world of difference on mine.

If your phone has had 2+ years of continuous use, you have definitely lost battery capacity. It does happen gradually.