Customer Reviews

Energizer L91BP-8 Lithium AA Photo Battery (8-Pack)

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The Energizer L91 Lithium AA cell is a fantastic power source. For high-drain applications, it offers great advantages over ordinary alkaline cell and rechargeable NiMH cell. However, it is also very expensive as a disposable battery. So it is important to recognize the strength of L91, and use it only in applications that give you the best results. Otherwise you'll be wasting your money.

According to data sheet published by Energizer, the capacity of the Lithium AA cell (L91) is 3000mAh. This number remains nearly constant with load current. In comparison, the ordinary Alkaline battery (such as the Energizer E91 AA) is rated as 2800mAh, but only at a very light load of 25mA. At a heavy load of 1000mA (typical for a digital camera or flash unit), its capacity drops to below 1000mAh. This number gets even worse at low temperature. At zero degree C and 1000mA load, the L91 can provide about seven times more energy compared to the E91. This is where the marketing claim of "Last up to 7 times longer" comes from.

When used in a digital camera at room temperature of 25 degree C, the L91 is more likely to last 3-4 times longer than alkaline. This is enough to justify its price, which is also around 3-4 times higher than alkaline. However, in low-drain applications (such as smoke detector, wireless mouse or remote control) alkaline cells will last just as long at a fraction of the cost.

The L91 also contains much higher energy when compared to an ordinary rechargeable NiMH cell such as the Energizer NH15-2500. This is partially due to its higher terminal voltage of 1.5V, which is 20% higher than that for NiMH.
Energy stored in NH15-2500 : 2.5Ah * 1.25V = 3.125Wh,
Energy stored in L91 : 3Ah * 1.5V = 4.5Wh (44% higher).

Higher terminal voltage for L91 is especially advantageous in digital camera applications, because your camera flash will recharge up to 20% faster. An added benefit is that the L91 weighs only 14.5 grams (0.5 oz) each, compared to 30 grams (1 oz) for NiMH. So your camera becomes much lighter.

The NH15-2500, like all ordinary NiMH cells, suffers from rapid self-discharge problem. If you charge up a set of those cells and leave them in your camera for a few weeks, you're likely to be greeted by 'Low Battery' sign when you try to take a photo. The new generation of 'ready-to-use' NiMH cells such as SANYO eneloop and Rayovac Hybrid solved this problem by having very low self discharge rate. But they have lower capacity of only 2000-2100mAh.

Bottom line: If you need AA batteries for a long hiking trip, then L91 is obviously your best choice. For most other situations, I recommend using low self-discharge NiMH cells for lower operating cost.

[Updated on June 8, 2011]
Note: Amazon has moved two of my previous reviews (one for Energizer Lithium AA 4-pack, one for 8-pack) under one page. Therefore I have to update my review to add some new information - or else I look like a fool who says the same thing twice.

=== New information follows ===

There seems to be some confusion about those Energizer Lithium AA batteries. Several people have bought those batteries under the assumption that they are rechargeable, only to be disappointed later.

Despite the name 'Lithium', those Energizer Lithium AA batteries are very different from the commonly known 'Lithium-ion' rechargeable batteries. Namely:

- They are single-use batteries (NOT rechargeable like Li-ion)
- The terminal voltage for each cell is around 1.65V (compared to around 3.7V for each Li-ion rechargeable cell)

The two types of batteries are not compatible. If your camera accepts AA cells, then you should use those Lithium AA cells and not Li-ion rechargeable battery. Alternatively, you may explore other rechargeable battery options, namely:

1. Low-self-discharge NiMH AA cells, such as Sanyo Eneloop or Sony Cycle Pre-Charged. Those have a operating voltage of 1.25V per cell, so some cameras (especially those that use only two cells) may not operate correctly on those.

2. Nickel-Zinc rechargeable such as PowerGenix AA. Those have higher terminal voltage of 1.65V, same as that of Lithium AA cells. The down-side is that the higher voltage may cause some older cameras to burn out, and the NiZn cells themselves have very poor lifespan.

No matter which rechargeable option you pick, remember that they each need their own special charger. Choosing a good charger is the key to longer lifespan for rechargeable batteries.

I recommend most people to try eneloop cells first. They are the most reliable among NiMH batteries. If it doesn't work well for your camera, you can still use those celll in other appliances such as flashlights or Wii remotes.

Finally, it is a good idea to keep a set of those Lithium AA cells as backup, or in case or emergency. They can be kept in storage for ~10 years!

The Energizer L92 Lithium AAA cell is a fantastic power source. For high-drain applications, it offers great advantages over ordinary alkaline cell and rechargeable NiMH cell. However, it is also very expensive as a disposable battery. So it is important to recognize the strength of L92, and use it only in applications that give you the best results. Otherwise you'll be wasting your money.

According to data sheet published by Energizer, the capacity of this Lithium AAA cell (L92) is 1200mAh. This number remains nearly constant with load current. In comparison, the ordinary Alkaline battery (such as the Energizer E92) is also rated as 1200mAh, but only at a very light load of 25mA. At a heavy load of 500mA (typical for a P&S digital camera), its capacity is reduced to about one-third. The difference gets even greater at low temperature. At zero degree C and 500mA load, the L92 can provide about seven times more energy compared to the E92. This is where the marketing claim of "Last up to 7 times longer" comes from.

When used in a digital camera at room temperature of 25 degree C, the L92 is more likely to last 3-4 times longer than alkaline. This is enough to justify its price, which is also around 3-4 times higher than alkaline. However, in low-drain applications (such as smoke detector, wireless mouse or remote control) alkaline cells will last just as long at a fraction of the cost.

The L92 also contains much higher energy when compared to rechargeable NiMH cell such as the Sanyo Eneloop AAA. This is partially due to its higher terminal voltage of 1.5V, which is 20% higher than that for NiMH.
Energy stored in eneloop AAA: 0.8Ah * 1.25V = 1.0Wh,
Energy stored in L92 : 1.2Ah * 1.5V = 1.8Wh (80% higher).

Higher terminal voltage for L92 is especially advantageous in digital camera applications, because your camera flash will recharge up to 20% faster. On the other hand, it may create problems with some applications such as unregulated LED flash light. Higher than expected voltage will make the lamp burn brighter, but the excessive heat may also cause the lamp to burn out quickly.

Bottom line: If you need AAA batteries for a long hiking trip or for emergency standby, then L92 is obviously your best choice. For most other situations, I recommend using low self-discharge NiMH cells for lower operating cost.

As a student who is very involved in clubs and organizations, I always want to have my digital camera at hand to capture unforgettable moments with my friends or the places that I visit.

When it comes to cameras, digital cameras are the worst with battery power. When I first got my camera, the pair of double A batteries that came with it only lasted an hour. I then bought a brand new pack later, and those also were unusable within 60 minutes.

This was going to be a major problem. I bought a pack of special Olympus Lithium batteries (very expensive and hard to find at the time) which lasted, at max, two and a half weeks.

Finally, I found a pack of Energizer Lithium batteries. I stuck them in my camera and expected them to last about five days. To my surprise, this pack of four batteries lasted me a whole month of road trips and hang-outs.

These batteries are long-lasting, reliable, very light, and inexpensive. I was very satisfied with the performance of these batteries, and I hope this review helped you in your decision or search.

These are "niche" batteries. They weigh half their Alkaline and NiMh brothers, store more energy, work in very low temperatures, and sit on the shelf for a decade without losing their charge.

As everyday consumables they make no sense (for that, look into Eneloop rechargeables). But as the cells that power your emergency flashlight, your GPS on the Inka Trail, or your radio during a blackout, they are a godsend.

Note that the voltage of these cells is slightly higher than regular AA's. Therefore, some devices actually *won't work*, at least not when the cells are fresh and fully charged! For example, people have posted problems with Garmin's Gpsmap 60csx or some regulated LED flashlights. I'd recommend you check with the manufacturer and test your device with those cells before placing them in your survival kit.

Wow! I'm probably going to change the way I look at batteries from now on. We stuck two of these in our Sony digital camera and put two more in the bag to use when these ran out, and went on vacation for two weeks. I'm not sure how many photos we took in two weeks, but after culling out maybe 50 that we didn't want, we wind up with 206. Many of these were taken using the flash. During the trip, I downloaded the pics to my laptop about 3 times directly from the camera, and that also takes a bunch of power. Since the trip, there was a social occasion where my wife took perhaps 20 pictures since she got conned into being the staff photographer.
After all that, the camera shows the battery as fully charged!!
We're about to go on a 18 day trip to So. America and what I'm going to do is to take the camera with the used batteries still in it, and take a spare pair. I WAS figuring on having to take my charger with an adapter plug which would have been just one more thing to lug to Peru. Not now.
I just ordered some more for the future. I doubt if I'll ever use rechargables again.
Yes, these are expensive. In my humble opinion, the cost is WAY outweighed by the convenience..

Aside from the ludicrous pricing, Lithium cells do vent small amounts of gas when you use them. This is normal in case you smell something when you open your device. Don't inhale the gas.

Check out their web site and you will find not all devices run 7 times longer, it depends on the drain of the device. These batteries do NOT hold 7 times the mA power.

Let's put it in perspective. A typical Alkaline AA holds about 2565 mA of power. Though 1.5v is nominal, they actually measure 1.6v when fresh. Voltage naturally drops as you use the battery.

Lithium AA's hold about 2900 - 3000 mA. Again, 1.5v is nominal, but they measure about 1.7v - 1.8v. Lithium also has a naturally straighter discharge curve and sustains usable voltage for longer periods of time. This is partly due to Lithiums having a higher wattage capacity than Alkalines.

When an Alkaline measures 0.9v and heads for the dead zone, it may still hold 1/3 of its' power, or more. This goes to waste as most devices simply stop when the voltage drops too far. Lithium not only has a higher mA rating, but they sustain higher voltage for longer times, and thus, drain much more deeply.

In a low drain device, this appears to last 7x longer. In reality, Lithium AA holds about 20% more power than Alkaline, and thus you may only see +/- 20% of extended run time. All depends on the device.

While your AA Lithium will eventually die, you could probably get some more use out of it in a good LED flashlight - though at reduced light output. Don't drain them too deeply, or they can explode like any other battery. When you stop getting usable light, replace the batteries.

Their resistance to heat and cold and longer life make them ideal for vehicle emergency devices, such as flashlights.

These batteries are expensive but they blow away the performance of alkaline batteries. I do a lot of backpacking and winter mountaineering and I use these a lot in my GPS and flashlight. AA lithium batteries are lighter and weight about as much as a AAA alkaline battery. These last several times longer in all conditions than alkaline batteries. Cold weather is where these really shine. These work to -40 degrees. Alkaline are terrible below freezing. If I am night hiking in the winter conventional batteries only last an hour or two in a flashlight. These will last all night long. Many cameras probably won't even work in the winter with alkaline batteries.

If you leave a flashlight in your car, buy a LED AA flashlight and put these batteries in it. It will actually work when you need it even in winter.

The only downside to these other than price is they produce a brief voltage spike when you turn something on. This should not be a problem in most electronic devices because they have voltage regulators. I find they are hard on bulbs in incandesant flashlights. I always brought 2 spare bulbs because I blew them frequently (tutning the light off and on frequently made this worse). I've never heard of a problem with these in LED flashlights.

I've found that rechargable batteries don't hold the charge very long--if my digital camera stays in my backpack with no shooting for several weeks, I can't depend on them. Regular alkaline batteries hold their charge but get used up quickly with a lot of heavy use like zooming, viewing pictures, etc. Li batteries seem to last months and months in terms of both holding their charge and surviving through heavy use. Also, I've read (don't know for sure) that Li batteries can function in wider extremes of temperature than alkaline.

These batteries went to feed a new camera battery grip I purchased at the same time. I've been shooting with the same four batteries for over 20 rolls now with a strong charge still present; they're very good performers and pretty long lasting that I see. Would recommend this brand to anyone interested in good, stable batteries.