Originally Posted by Fire Escape
Guess that I should get with the times and look into what is out there for Li Ion batteries. How do actual run times compare with 'disposable' 123s? Do they 'store' well without losing strength?
Li-ion (RCR123/16340s) have ~50-60% the energy of lithium primaries (CR123) or 3.7V x 650 mah = 2.4 watt hrs vs 3.0 x 1500 mah = 4.5 watt hrs. While it is true that Li-ions don't self discharge like other Ni-based rechargeables, Li-ions do not like to be stored at full capacity - they'll permenantly lose about 20% of their capacity per year stored at 100% at room temp. Not all lights can handle the additional voltage (up to 4.2V fully charged) of Li-ions, make sure your light is rated for them.
Best to use Li-ions and store Lithium primaries.