- Joined
- Apr 7, 2003
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- 2,315
I've seen a lot of interest in flashlights in the G&G forum, but little discussion of batteries. I recently bought a Fenix LD20 and did some battery research... thought I would share that with you.
AA Style/size batteries come in a few different types. For the sake of argument, I'm not going into the exotic batteries that are sized like AA's but actually deliver higher voltage, as these can burn out some lights. All of these batteries can be found (under various manufacturer's names) at my local Walmart, and probably at yours.
A. Heavy Duty
B. Alkaline
C. Lithium
D. Nickel Metal Hydride (NiMH)
E. Nickel Metal Hydride Hybrids
A. "Heavy Duty" - Old battery technology, has no advantages other than being cheap. Avoid at all costs.
B. Alkaline - These are decent standard batteries for normal tasks. Non-rechargeable, can be bought in bulk for good prices.
C. Lithium - Non-rechargeable, expensive, light weight. Lithium batteries have a higher energy density than alkalines, which is good, but they have two other big advantages... they don't "self discharge" much, and they work at really low temperatures much better than alkalines. These batteries are perfectly happy sitting on a shelf for a decade before being used, and they'll still be at nearly full charge.
D. NiMH rechargeables - These are the batteries that replaced the old Nickel Cadmium (Ni-Cad) rechargeables from a few years back. They are vastly superior in that they don't take a "memory" and can be recharged hundreds of times. You can get good energy densities, but be sure you shop for high capacity. You can buy AA batteries with anything from 1900mAh capacity to 2800. The more, the merrier. These batteries DO self-discharge pretty rapidly, somewhere around 1% a day. So, charge them all the way up and sit them on a shelf, they'll be useless in 3 or 4 months.
E. NiMH Hybrids. - These are more expensive than regualar NiMH, but offer a compromise between the low lifetime expense of NiMH and the shelf life of Alkalines. A NiMH hybrid doesn't charge to as high a capacity as regular NiMH, but will hold that capacity much better, as they've been designed to self-discharge at a low rate. I've read of types that hold 85% power after 6 months storage. These batteries are pretty new on the market, so expect improvements as the makers work out the chemistry.
So, what does this mean? It means you have some choices, which is a good thing! I prefer rechargeables for their lower lifetime cost and lower environmental impact, so those are what I mostly will be using. I bought a good charger (Maha MH-C9000) to keep the batteries in good shape, so I've bought NiMH hybrids for every day use. I probably won't use the flashlight all that much, and these batteries should be fine with a re-charge every 3 months or so, just to keep them perked up. Regular NiMH batteries would self-discharge too rapidly for me, but if you were to change them out every month or so, they would probably work just as well. For backup batteries, I'm keeping a pair of Energizer "Advanced Lithium" batteries in my bag. These will keep their charge for a decade or so, so they'll be ready should I need them.
Another consideration (especially in Canada) is operating at lower temperatures. From a chart I saw on Candlepower Forums (which I can't find at the moment), alkalines are the worst when it comes to low-temp operation, with all of the other types being better. Lithiums are especially good at low temp applications, so (combined with their excellent shelf life) would make them the best for a flashlight you store in your car.
Anywho, I'm no expert on this, but this is what I gleaned from my research. Hope it helps some with your flashlight joy.
AA Style/size batteries come in a few different types. For the sake of argument, I'm not going into the exotic batteries that are sized like AA's but actually deliver higher voltage, as these can burn out some lights. All of these batteries can be found (under various manufacturer's names) at my local Walmart, and probably at yours.
A. Heavy Duty
B. Alkaline
C. Lithium
D. Nickel Metal Hydride (NiMH)
E. Nickel Metal Hydride Hybrids
A. "Heavy Duty" - Old battery technology, has no advantages other than being cheap. Avoid at all costs.
B. Alkaline - These are decent standard batteries for normal tasks. Non-rechargeable, can be bought in bulk for good prices.
C. Lithium - Non-rechargeable, expensive, light weight. Lithium batteries have a higher energy density than alkalines, which is good, but they have two other big advantages... they don't "self discharge" much, and they work at really low temperatures much better than alkalines. These batteries are perfectly happy sitting on a shelf for a decade before being used, and they'll still be at nearly full charge.
D. NiMH rechargeables - These are the batteries that replaced the old Nickel Cadmium (Ni-Cad) rechargeables from a few years back. They are vastly superior in that they don't take a "memory" and can be recharged hundreds of times. You can get good energy densities, but be sure you shop for high capacity. You can buy AA batteries with anything from 1900mAh capacity to 2800. The more, the merrier. These batteries DO self-discharge pretty rapidly, somewhere around 1% a day. So, charge them all the way up and sit them on a shelf, they'll be useless in 3 or 4 months.
E. NiMH Hybrids. - These are more expensive than regualar NiMH, but offer a compromise between the low lifetime expense of NiMH and the shelf life of Alkalines. A NiMH hybrid doesn't charge to as high a capacity as regular NiMH, but will hold that capacity much better, as they've been designed to self-discharge at a low rate. I've read of types that hold 85% power after 6 months storage. These batteries are pretty new on the market, so expect improvements as the makers work out the chemistry.
So, what does this mean? It means you have some choices, which is a good thing! I prefer rechargeables for their lower lifetime cost and lower environmental impact, so those are what I mostly will be using. I bought a good charger (Maha MH-C9000) to keep the batteries in good shape, so I've bought NiMH hybrids for every day use. I probably won't use the flashlight all that much, and these batteries should be fine with a re-charge every 3 months or so, just to keep them perked up. Regular NiMH batteries would self-discharge too rapidly for me, but if you were to change them out every month or so, they would probably work just as well. For backup batteries, I'm keeping a pair of Energizer "Advanced Lithium" batteries in my bag. These will keep their charge for a decade or so, so they'll be ready should I need them.
Another consideration (especially in Canada) is operating at lower temperatures. From a chart I saw on Candlepower Forums (which I can't find at the moment), alkalines are the worst when it comes to low-temp operation, with all of the other types being better. Lithiums are especially good at low temp applications, so (combined with their excellent shelf life) would make them the best for a flashlight you store in your car.
Anywho, I'm no expert on this, but this is what I gleaned from my research. Hope it helps some with your flashlight joy.
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