I have a L&M Arc HID and while it is enough light for me the 3 hour burn time is just not enough. I need something that will burn at least 6 hours if not all night... There are a ton of options out there and I'm having a hard time sorting through them all.

The easiest thing to do would be to buy a Li-Ion battery for my current light but it is three years old and I'm wondering how much life the bulb has left...

That brings me to LEDs which make the most sense but there are dozens of choices.. Price is a factor, the less I spend the better, but it needs to be reliable and tough. I could sell my l&m and use that money to buy something a little better or I could hold onto it and buy something to use in addition to it (though I'm not crazy about having to switch lights in the middle of the night).

The price on those magicshine lights is sure nice. Is it possible to buy a longer lasting battery for them?

It will be used for technical cross country riding and adventure racing...

Any recommendations or help sorting through my options is greatly appreciated!