I I'm in the market for a performance flashlight. Should the type of batteries used be a consideration? I use Ni-MH AA's in my digital point and shoot camera and have a LaCross BC-900 charger for them.
John
It's certainly a consideration. If you plan to use the lights regularly, CR123's are costly. Lithium rechargeable batteries are available, but comparatively exotic. If you use them in multi-battery setups, be sure and monitor their condition carefully. There is a hazard related to voltage reversal and even ka-pow effects.
Lithium primaries (CR123) can be purchased for as low as $1, but current wisdom is to stick with the Japanese or US made batteries, at more like $2 each. They offer good power-weight, but if you plan to use them regularly, consider the expense. Based on total power delivered, a CR123 primary has a marginal advantage (30-40%?) over a NiMH AA, and the higher voltage means the circuit needed can be simplified.
My first real performance flashlight was a Surefire 9P (3xCR123). With a Cree based P60 LED drop in, it is still a nice performer. It can go through $5 worth of batteries in a few of hours, though.
IMHO, we've reached a point where the AA format with low discharge NiMH will deliver great performance in a light that has the necessary buck/boost circuits.
I began using the AA NiMH batteries for digital cameras, as well.
I now have a MH-C9000 charger, and a pile of the Sanyo Eneloop batteries. My favorite lights are now the Fenix L2D (2xAA), the Fenix LD01 (1xAAA), and a JetBeam Jet-1 Pro (1xAA).
My JetBeam has a beam quite similar in throw and brightness to the Surefire 9P, at less than half the weight and volume.
I probably use the LD01 the most. It gets regular daily use. Swapping to freshly charged Eneloops about once a week is cheap and easy, and with a good charger (BC-900 is fine) you have zero recurring cost in power, and can get years of use from each battery.
Many discussions favoring CR123 based lights seem to reach a point of saying that if your life depends on the light, you don't weight the cost of the battery much; or using the legendary reliability of the Surefire lights as a prime consideration. The best of the CR123 lights can outperform in ways - the battery is compact, and it gives you 3V without any circuitry at all.
With AA based lights, the efficiency of the power circuit (which by necessity sinks some power) and how well it can regulate is a factor. OTOH, you have the advantage of multiple light levels, etc. when you do have such a circuit in your light. Switching low voltage, and even the contact resistance at the battery terminals is a consideration for a flashlight that can use hundreds of milliAmps at 1-3 Volts. Any Voltage drop due to resistance or circuit inefficiency causes lower or reduced output that is easily seen or measured.
The bottom line for me is yes, the batteries are a huge factor. Think about how you'll use the light, and make that a factor in choice.