Leaving Flashlights "Loaded"- Draining Batteries?

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Sep 4, 2006
Hey guys... had a question about storing flashlights "loaded" with batteries in them. Do batteries slowly lose charge while in the flashlights, not being used?

Been working on updating some BOB bags and go bags in the cars. Wondering if I should leave batteries in flashlights or not. Or, put some sort of cardboard/plastic "interrupt" to break the circuit and help prevent loss of charge.

I have various flashlights ranging from Surefire A2, E1E, Vital Gear FB2, Dorcy Spyder, mini mag lites.

With the maglites specifically, i've noted that over time, the batteries (normal energizer/duracell AA's) seem to lose their juice.

I want the lights to be "good to go" when I need them, with minimum messing around yet i don't want to be swapping out CR-123's all the time to keep the lights operational. I was thinking of cutting a plastic disc, the size of a CR 123, and putting it in the tube to help preserve the batteries.

Thanks in advance!
I am sure there are people more expert on the subject then I am. But, I will say my father in law is an electronics engineer with an interest in batteries.

He has told me in the past, once you use a battery for much at all, it starts a chemical reaction that starts the degredation (losing power) go faster. Simply leaving BRAND NEW batteries inside the flashlight should not cause them to lose power faster then storing them otherwise.

Heat is an enemy to batteries. There is also the risk of battery leakage causing damage to the light.

Father-in-law now recomends the new lithiums for disaster prepareness or high energy applications due to their long shelf life and energy delivery capabilities. I know Eveready makes them in AA, and AAA sizes and maybe others. They are quite a bit more expensive but deliver performance accordingly.
so, if i have brand new batteries, I'm better off not putting them in the flashlight at all to prevent that chemical reaction from starting in the first place?
Lithium primary cells are fine in a flashlight, providing they were of like voltage when they went in. NiMH and NiCd cells are a bit different; both will self discharge to some extent.

NiCd rechargeable cells are best left in a trickle charger.

what kind of light do you have, and what kind of cells are you feeding it?

(mandatory plug for www.candlepowerforums.com )
so, if i have brand new batteries, I'm better off not putting them in the flashlight at all to prevent that chemical reaction from starting in the first place?

It should not make a difference where they are stored (in or out of the light) as long as they are not used before storing.

I don't know of a flashlight that bleeds the charge off when switched off. However mini-mags have that odd switch that may be activated accidently.

Old boy scout trick is to reverse the batteries (+ to +, or - to -) so the light cannot be accidently turned on.

does simply loading the new batteries into the light (and not turning it on) cause the chemical reaction to start?
I don't know of a flashlight that bleeds the charge off when switched off

there are various lights like the HDS models that are driven by a microprocessor that DO incur a small voltage drain when off; as well as the already mentioned self discharging rechargeable cells.
The beauty of the lights that use the CR123 lithium batteries is the 10 year shelf life of these batteries. I buy in bulk (usually 15 at a time) for about $1.40 each. In this way, I always have plenty of hot spares that can be re-loaded. Perfect for your go bag. I also invested in one of the Surefire carrying case that carries an extra bulb/reflector assembly, and 6 spare batteries. It is waterproof. Again, perfect for the go bag.
Battery drain

I guess this didn't post so I'll try again.
Normal flashlights should not draw current when they are switched off but as somebody mentioned, the new "exotic" flashlight do. Batteries have an "internal resistance" that determines how many amps can be drawn from them when they are used. Ni-Cads and Lead-Acid have a low internal resistance which allows large amounts of current to be drawn from them. That's why they use them in your car and high current electronics such as video cameras. The trade-off is that it also causes them to discharge internally (go dead) quickly when they are not used. Alkaline and lithium are medium resistance so they store well for long time periods but can't produce as many amperes of current when in use. The thing to remember is that all batteries can leak their electrolyte. What will that do to your device? I like alkaline batteries for long storage and performance verses cost. But for long-term storage I keep them outside of any device that is aluminum such as a Mag-light because if they do leak, they will eat the aluminum. However the electrolyte doesn't do much to steel and copper so I leave them in my Geiger counter. If they leak, just use mild soap and water to remove the electrolyte and let it dry thoroughly before you use it again. Carbon batteries have an electrolyte that attacks copper and steel but not aluminum. However their storage time and performance is not that great. For emergencies, I have an LED flashlight that has a plastic case and I use three alkaline "D" cells in it. They have a shelf life of years, the light will shine for three months of use and if the batteries leak, which some did the other day, soap and water cleans it up with no damage.
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