Energizer rechargeable 1W LED (Target clearance)

Just purchased one of the Eveready Energizer 1-watt rechargeable LED flashlights at Target. It was on clearance for $19.98 (originally $39.99).
OK, it's not my "pride and joy" flashlight and I haven't really had time yet to fully test it out, but I thought for that price I'd give it a whirl.
Has anyone tried to upgrade the LED and/or battery in this light? Maybe I would be better off to just leave it alone, but I'm tempted to experiment with this one (unless the LED is too "tamper-proof", that is).
The rechargeable battery measures about 17mm diameter by 85mm in length and is a "1/2A 1000mAh 3.6V NiMH".
Ideas, anyone?

Curious. NiMH implies 1.2v, so you'd expect 3 cells in series. If the 85 mm is correct, you have 3x17300 or so. AAA cells are 10mm, AA 14mm in diameter.

Sounds like a 17670 would fit if you wanted to go Li-Ion; don't use the NiMH charger, of course!

Edit: just looked it up. You said A, not AA. A 1/2A is 17x25.

Yes, the battery is actually 3 (1.2V) cells in series. They are probably soldered together where they meet and they are wrapped in a white plastic "shrink wrap" type of material. The overall length of the battery that I stated (approximately 85mm) includes the positive battery tip.

I was thinking of trying a 17670 lithium-ion rechargeable--thanks for your suggestion. I might have to make up a small "dummy" spacer to make up the difference in length, but that should be no problem. You are correct that if I used a 17670 that I would need to use an external charger designed for that battery.

I'm fairly certain that I can install a SSC Seoul P4 (U-bin) emitter. It would definitely be a test of my soldering skills!

It is on sale now at $9.99. You cannot tell by looking at the red tag but once you scan it the price will be $9.99. I'm going back to buy more. Nicely built. :twothumbs