Got any idea what batteries I should get for a flashlight in my car?

[boring]

Easy. One of the oldest items I own is an original Surfire 6P in aluminum. I've had it with CR123 cells in my car for over 20yrs. I 'think' I am on my third, or possibly 4th pair of cells. I mainly only use it for the occasional roadside assist, or checking my oil, or tire-pressure at night.

I have a 6p and after the original batteries, it has only been super dim. I really need to contact surefire. I guess. if I have to.

 

[22-rimfire]

What I do..... I buy a number of the same flashlight and put a number on each (so I can tell them apart). I keep at least one each vehicle, but since I use the same flashlights elsewhere, I rotate out the ones in a vehicle. I use regular Duracell batteries. When they get dim, I replace the batteries. New ones go into the vehicle. The difference is that I don't leave the same flashlight inside the vehicle over time only to discover that the battery charge is really low when I might need to use it. I don't really like to spend the money on expensive batteries, but I also do not like to find that a battery leaked and potentially ruining the flashlight. I use flash lights a lot, so I notice when the batteries start getting low.

 

[rbmcmjr]

As Jared stated, CR123 primary lithiums are the top choice for this application. Do not use the rechargeable versions.

The other issue is with control circuitry. You want a mechanical switch rather than an electronic one. A setup like this can last for years without problems. I use a 6P with a Cree XM-L2 emitter for this application.

 

[SpyderPhreak]

Great point about the switch Rick! Even a tiny, tiny drain on a powered electronic switch adds up over time. I have some lights like that around the house, and if possible, I'll back off the tail cap about a turn so that the circuit is interrupted to prevent any parasitic drain. My Li-Ion headlamp is this way.

 

[evltcat]

AA Lithium Ions? Is that what you really meant (rechargeable, ~14500 size), or did you mean primary Lithium cells (non-rechargeable)? Just want to be clear here, as there are not many 1.5v Li-Ion batteries out there, and the 3,000mAh you state makes me think you meant primary Lithium cells (like the Energizer Lithiums).

Good call on the 3xAA's to D cell adapters though! I use 3xEneloops with those, and they work great!

Many moons ago on CPF, I actually came up with an adapter for a 3D mag light that held 12 AA's in a series-parallel configuration for a regulated Luxeon 5 Watt LED conversion (2 sets of 6 batteries in series). There was *just* enough room inside of the light body to fit 4 AA's in place of one D cell, with a rod running down the middle and one on the outside between each battery. The adapter was quickly dubbed "the paint roller".



I think you'll be amazed how well the Eneloops work in the 3xAA to D cell adapters. They still work well in the cold (unlike Li-Ion), they don't leak, and they self-discharge very little, which makes them perfect for long-term storage like a vehicle flashlight. Overall, the Eneloops are hard to beat. About the only place where I prefer Li-Ion is in very high-drain applications, where the NiMh chemistry can't keep up with the current demand. Not too many places where that's the case, however.

Spyder,
Yes thank you very much for cleaning that up, sorry I wasn't clear. I do mean Lithium Primary AA's (Energizer). Mainly for the no leak, long shelf life. I'll have to try the low discharge enloops. I have a bunch of budget NiMh and they discharge really fast.

 

[SpyderPhreak]

Spyder,
Yes thank you very much for cleaning that up, sorry I wasn't clear. I do mean Lithium Primary AA's (Energizer). Mainly for the no leak, long shelf life. I'll have to try the low discharge enloops. I have a bunch of budget NiMh and they discharge really fast.

No problem, glad I could help!

 

[u812]

This is why I have stopped buying anything that does not use a battery that I can get in a lithium. Maglights never worked when I needed them. I use AAA and AA lithium batteries in all my lights. Never had them go dead or leak sitting in a light even in hot or cold weather. The one in the ARC AAA on my key chain has been in it for about 4 years and is still good. I will change it out soon just to be sure.