Infinity with a 544 battery?

First, let me say that I am very satisfied with my Infinity (Smoke/grey with white led). Though it doesn't provide as much light as some other one cell flashlights, it gives me enough light for my purposes. And since the battery life is quite long, I'm sure it will be very reliable.

However, I love to mess with things. I was searching through some old posts and discovered that some people have tried several modifications on the infinity.

One caught my eye since it didn't sound like it would be difficult or permanent. He stuck some aluminum foil in it at then used a 544 battery to power it. The results were that it was brighter but that it didn't las as long.

Would doing this damage the led or can it handle the additional power? If it is too much power, would sticking a resistor in there help? If so what resistor would be appropriate (sorry, still new LEDs and don't quite know how to calculate all this stuff). Does anyone know how long a battery would last with this setup?

Thanks.
By the way, I posted here instead of replying to the original post because I wanted to get a broader range of input.

I got this idea from Brad, after I ripped the circuitry out of an Infinity. I used the 544 battery intermittently, over a period of weeks, so I can only guess it lasted a few hours. Also, it works fine without a resistor. But if you you have step up voltage circuitry in there, it might be too high.