Energizer Rechargeable AA Nimh Batteries (8 Pack) Reviews

• Shockingly high self-discharge rate!,

  
  By AOEAD7DPLZE53 on 2006-11-29
  All rechargeable battery manufacturers love to boast about their product's current capacity (mAh). But there is a dirty little secret that they don't want you to hear: self-discharge rate. Simply put: a fully charged NiCd or NiMH cell will gradually lose its stored energy over time. Technical papers I have researched typically put the self-discharge rate at 10-20% per month for NiCd cells, and 20-30% per month for NiMH cells. This kind of self-discharge rate is usually acceptable in applications such as digital cameras.
  
  I bought 8 of those Energizer 2500mAh rechargeable NiMH batteries over one year ago. At first, I was very happy about the large current capacity offered by those batteries. But within a few months, I started to notice that they die very quickly in my digital camera. In fact, a set of Sony 2300mAh NiMH batteries I bought one year earlier seems to last much longer when used in the same camera.
  
  I recently did some controlled experiments (using the LaCrosse BC-900 AlphaPower Battery Charger) and found out what's wrong: The Energizer NiMH batteries have very high self-discharge rate. After fully charging all 8 cells and left them on the shelf for one week, five of them lost over 30% of their charge, and the other three lost about 20%. In comparison, the set of older Sony batteries only lost around 10% over the same one-week period.
  
  So what this really means is: if I charge up those Energizer 2500mAh batteries and leave them in my camera for three weeks, they will become totally exhausted. I found this kind of self-discharge rate completely unacceptable, therefore I strongly advise against buying those batteries.
  
  [Update on April 9, 2007]
  I have hardly used those Energizer 2500mAh cells in the last few month. Now they have deteriorated even further. Five of them can't even hold their charges for more then a day.
  
  Instead of the Energizer 2500mAh cells, I recommend buying the Rayovac "Hybrid" 2100mAh cells. They have very low self-discharge rate (see my review on "RAYO 4PK AA") and are cheaper than the better-known Sanyo eneloop 2000mAh cells.
  
  

• Excellent Replacement NiMH batteries

  
  By AUHSOLGN7T7QC on 2004-10-27
  I have three cordless Uniden phones that all have serious battery charge problems wit the original 1500 Mah batteries. I bought these (2300) and charged overnight. They work great and are the best battery out there for AA nimh required devices. Don't buy no-name garbage to save 10%, not worth damaging your electronics over it.
  
  
  

• Not so good for digital cameras

  
  By A2AMSRZ766PB6L on 2007-03-07
  I gave these cells lowest possible rating because sharp decline in performance after only a few months of usage in a digital camera is not acceptable (especially considering claims on the package that these cells are GREAT for... digital cameras!). But also because much better alternatives have come on the market (e.g. Sanyo's Eneloop cells) and there simply is no reason any more to buy the Energizer 2500mAh as they have become obsolete.
  
  I have experience using these cells for the past 2 years in 3 distinct and very different usage patterns:
  
  1. My sister used 2 pairs in a digital camera
  2. My mother used 3 pairs in a wireless mouse and keyboard
  3. I used 6 pairs in various baby toys (non-motorized baby toys that play sounds and flash lights) as well as in Bluetooth keyboard/mouse and back-light IR remote control.
  
  Because each set was never mixed with other batteries (they 'lived' in different households) - I can draw some conclusions on how these batteries hold up under varied usage conditions (by which I mean - various discharge profiles from the most intense - in digital camera - to the least intense - in IR remote controls and baby toys). Also - it's worth noting that all 3 sets of batteries were charged with identical chargers - the Maha MH-C401FS and they were ALWAYS charged on 'slow' or 'gentle' setting (around 5 hours per charge; I made sure my sister and mother understood very well to never EVER use the 'fast' 100 minute setting as it's detrimental to battery life). By the way: none of the sets got anywhere near the 1000 re-charge cycle touted on the packaging.
  
  So what are the results of the 3 tests?
  
  My sister, who put the most strain on her batteries in a high-drain digital camera, essentially killed her 2 sets. She still uses them - but they hardly hold charge any more.
  
  My mother's cells still work - but they only hold sufficient charge to power her keyboard/mouse combo for about a week before they have to be recharged. Wireless keyboard / mouse is a rather low drain device though they do not have a 'sleep' function (pls see below for how this compares to a Bluetooth version).
  
  
  My batteries - under the least strenuous usage of all 3 sets - held up the best. They still hold charge long enough to power any of my devices for 30 days or better. IR remote only actually drains batteries when you push buttons. Baby toys I use these cells in don't have any motors - and just like the remote control - only drain the cells when the kid presses buttons. Drain is fairly low (most of the toys simply play sounds; some also flash LED lights; none have moving parts). The Bluetooh keyboard and mouse are also low drain and unlike their 'standard' cordless brethren - they go into 'power save' or 'sleep' mode when not used for a number of minutes. This saves tremendously on power usage.
  
  Given my experiences - the bottom line seems to be that these are OK as long as you don't plan on using them in a... digital camera. Just like other reviewers have noted - these cells are excellent in any kind of device when brand new. But after a few months of running them through their paces - they seem to kick the self discharge rate into overdrive. I hardly experienced this self discharge acceleration (though all of my cells did lose about 300mAh of capacity under my usage over the past 2 years; as tested by my newly acquired LaCrosse BC-900 charger). But both my sister and my mother definitely noticed a sharp deterioration.
  
  However, all of this discussion is of little more than historical value at this point. 2 years ago - there were not that many other options for high capacity Ni-MH cells and these Energizer 2500mAh batteries seemed like a good idea. These days - Eneloop cells are available from Sanyo and other 'low self discharge' Ni-MH batteries are also available (often advertised as 'pre-charged' batteries; Wal Mart sells a product called Rayovac Hybrid for less than these Energizer cells; even RadioShack has a house brand; though at ridiculously high price and made in China). So I no longer see a reason to buy the Energizer 2500mAh cells - especially given that Japan-made Eneloop cells from Sanyo are only slightly more expensive. I'm in the process of replacing all of our batteries with Eneloops. Stay tuned for Eneloop review in... 2 years ;-)
  
  

• Terrible Self-Discharge Rate

  
  By A1TRPYZV5K8U7U on 2006-12-12
  I bought 20 of these on the recommendation of others. THey worked great for about 4 months, and then they stopped holding a charge. I can charge them up and leave them in my camera for a few days and it will tell me they are dead.
  
  Energizer NiMH are no good; go with Sanyos instead, you won't be disappointed.
  
  

• awesome batteries

  
  By A2I357I10ZY7CI on 2006-02-15
  Like serveral below, i am using these with my Canon S2 IS. I think they are awesome. I'm very picky about battery life and i think these last great. i don't have them long enough to know if they diminish over time. I used these battery in a mini tape recorder too. It lasted over several days at 1 hour record time each day. I do have an 8 hour charger and it doesn't bother me one bit. Haven't anyone heard "faster isn't better?" I wouldn't trust the 15minute charger. who knows what it does to the battery. i am content with waiting for 8 hours and be sure my battery recieves a complete charge. I wouldn't hesitate to buy these again.
  
  
• Poor Longevity
  By A38HFW7O4IBHE2 on 2006-06-10
  When I bought them I was super impressed, great longlasting power. After about 2 dozen charges the longevity went South. Now they totally discharge by themselves in a week or less
  
  
• Great stuff
  By AQOVK92N8ZDV0 on 2005-10-17
  I bought these AA batteries a while back and it is still working well. I bought some cheap ones before to save a buck or two, but didn't last that long. It was a waste of money. I use these batteries mostly for my Nikon coolpix camera. Just charge over night and it'll be ready the next morning.
  
  
• Long Lasting - Great with the 15 Min Recharger
  By A19D7X37II1V6I on 2006-01-11
  I have purchased a total of 16 of these rechargeables. These are the best 2500 mAh rated batteries I've ever used. I've also tried the Sony 2500 mAh and the Duracell ACCU 2500 mAh and returned those since they did not work as well.
  
  I use these batteries primarily in my sister's Roboraptor toy. The Roboraptor is a high drain device (walks and bites) and eats up regular alkalines very quickly (Energizer Max, Duracell Coppertops, and even the Ultra and e2 series). These 2500 mAh not only last longer, but they also seem to deliver more power to the toy resulting in improved walking performance and quicker snaps and lunges at your hands (to my sister's fright). Don't worry about the 1.2V rating which is lower than a regular alkaline rating of 1.5V.
  
  These batteries also work well in my wireless keyboard and in various remote controls although these are low drain devices. In the past 5 months, I have not had to recharge those once. They are probably better suited where batteries would normally have to be replaced more often.
  
  You can buy these 2500 mAh cells in either 4 pack or 8 pack individually. They can also come paired with a compact 8 hour charger (comes with 4 2500 mAh cells). I have used this charger before and it is very slow. It charges 4 cells at a time on an 8 hour cycle and does not feature any sort of detection ability to stop charging when the cells are full. Energizer also makes another charger - a 15 min quick charger. It is more bulky but it charges these 2500 mAh batteries in 20 min or less. However, the charger itself doesn't come with any 2500 mAh...instead it comes with 2250 cells. This charger will stop though once the batteries are fully charged. With this technology comes a higher price though.
  
  
• The best NiMH AA batteries
  By A1AJMEOTBPEAZ7 on 2006-08-31
  I use these batteries with the Energizer Quick (15-min) charger. It's important to note that these are the 2500 mAH batteries. Energizer also makes 2100 and 2200 versions that are sometimes erroneously listed as 2500 on others' websites. These are the real deal.
  
  They charge within 15 minutes in the charger and keep their charge as indicated. I keep extras with me when I am photographing, as my flash is power hungry. I often get more flashes out than the manufacturer claims is possible with its own proprietary battery.
  
  I have charged, discharged, and recharged them many times with no noticeable loss. They do get very hot in the charger and need to cool before using. Also--and this is probably obvious--they do not work once wet, even if allowed to dry. (I had an unfortunate experience with a canoe and a lake.)
  
  
• Agree with comments that it's not good for digital cameras
  By AAJIGWE242MSN on 2007-05-22
  These batteries have phenomenally high self-discharge rates, going so far as to be "dead" after 10-20 shots in a digital camera (and no more than 1-2 weeks since last charge). They died quickly in my Nikon SB-600 (flash) and, after relegating them to my wife's Canon S3, they died even faster. Luckily I paid a relatively low price for them at Sam's Club. I recently purchased a Lacrosse BC-900 so I'll see if that helps any (perhaps a dead battery or something).
  
  Interestingly enough, I never encountered this in my experiences with the 1700 and 2100 Energizer NiMH's. Go figure.
  
  
• Less than satisfied
  By A4TXW31Y1P06E on 2006-02-02
  I bought two sets of 2500 mAh NiMH Energizer batteries and have been less than satisfied with them. I am using an Energizer NiMH battery charger (the 6-7 hour timer type) and the batteries die after only a few shots in my Canon Powershot S2. One set dies after taking a picture or two -- this is immediately after charging them. I have since disposed of this set. Interestingly, their performance was very impressive at first, allowing two days worth of shooting hundreds of pictures and lots of video, but in the four months that followed, their longevity has greatly diminished. I have charged the batteries perhaps 30-50 times at most, and I believe these are rated for around 500 charges. I am currently looking elsewhere for a better NiMH battery solution.
  
  
• mah 2300 or 2500??
  By A3M1WO9RQ4T3C9 on 2006-02-09
  is it just me or can't anyone see that the picture in the bottom left side say these batteries are 2300mah while the description says 2500mah. Which is it??
  
  
• work great, for less then a year
  By A16P3Y2QP2F7VP on 2006-11-02
  Have 8 of these to use with a hot-shoe flash. They worked great for a year (maybe 20 charges at most), then they pretty much died and won't hold any charge. Better then disposables but still disappointing.
  
  
• Nimh Batteries are Great!
  By A2C04XXI0N5H5T on 2006-04-26
  Great in digital camera. Took 400 photos on trip to Mexico.
  Way out-last conventional for short intense power needs.
  They do lose power just setting around over a month's time. Make sure they are freshly charged before extended use.
  
  
• Great Longevity in High Current Drain Applications
  By A20S4G1EXF2OM7 on 2006-09-18
  These batteries are do a great job of providing long life in high curent drain applicaions. I recently bought my wife an iGolf GPS unit that measures the distance to the middle of the green using GPS technology. The unit works great but only lasts ~ 10 hours on a set of alkaline AA batteries. After looking into some alternatives I found that these Energizer AA NiMH batteries have the highest capacity (mAh) of the brand name batteries available. The result is that after a full charge she can get upwards of 12-14 hours of iGolf usage before the batteries run out. You can access the technical specification sheets on the enegizer web site and detemine if they would work well in your particular application. I suspect that some of the other reviewers which are having problems may be using them in devices where 1.2V (NiMH chemistry) do not work well and require a conventional battery (zinc carbon or alkaline) that delivers a full 1.5V. If your application can use the slightly lower voltages that these deliver then they are a great buy and should save you some money in the long run.
  
  
• Poor Longevity
  By A7C8FSEP9EO4Z on 2006-11-13
  Recharge 1000 times? We have recharged these batteries 50 times at most and then they start to fall of real fast. I was surprised because I really believed they were the best way to go.
  
  
• The battery self discharge rate is horrible.
  By A2AXPOZANA8GV2 on 2006-12-26
  I have bought two sets of Energizer NIMH AA batteries and had them for
  about 1 year. As others have reported they seem to work fine for
  about 2 to 3 months and then they self discharge rate makes the
  batteries almost unusable. After fully charging the batteries
  and trying to use them one week later my digital camera will
  tell me to change the battery pack without even using them.
  
  
  
• Not good for digital cameras
  By AM11LSGKZG5U4 on 2007-05-18
  I just bought these recently to use in my digital camera while on vacation. After fully charging them and inserting them in the camera they almost imediately showed a low battery icon on the camera. Several times I tried charging them, and then tried to use them with the same results. I was trying to avoid purchasing disposable batteries, since I take ALOT of pictures, but unfortunately that's what I ended up using.
  
  
• With Patience these are very good batteries.
  By A2OYRP5AIWBZ4S on 2006-01-29
  They take eight hours to charge and the first few times you use them they do not last as long as you might like, but then they last as advertised, longer than non-rechargeable batteries. Not sure if the other brands that charge faster work as well as these or not.
  
  
• Terrible self discharge rate
  By A3E92HPHZRUOAH on 2007-08-01
  I put these in my kid's toys. They were dead in a week without the toy being used. The Energizer Bunny would be dead before he was turned on. By contrast the Panasonic HHR-3UP equivalent lasts for months.
  
  If you are going to charge and use right away, they'll be fine (e.g. tape player). If you put them in something (camera, toy, flashlight) that you may want to use later, forget it.
  
  
• Don't even bother
  By A25EPLCBAOLY67 on 2008-03-15
  Since I have a lot of devices that use batteries (X360 controller, remotes, clocks, camera, wireless keyboard/mouse, etc.), I decided that using rechargeable batteries would be best. I decided to invest some money in a couple of these batteries (roughly 16 AA and 8 AAA). Starting off with only 4 AA, it slowly amounted to what I have today.
  
  In a nutshell, I've never been so disappointed in a set of batteries. I understand that you can't rely on cheap batteries, but I figured that I couldn't go wrong with sticking with the big names when it comes to dependability. This is where Energizer has completely convinced me otherwise.
  
  If you just picked up a set of these batteries, they'll seem amazing for the first few usages. I have had some of these batteries for almost 2 years now, and they are all but dead. I'm not talking about leaving them on the shelf, I'm talking about dead right off the charger. I'm using the LaCrosse BC-900, so I know its not the charger. Prior to that I use to use one of Energizer's $30 chargers, but switched because I thought that the charger was the only problem. I sure felt like an idiot a year ago when I was asked to be the photographer for a rehersal. For this, my camera was the Canon A620 which uses 4 AAs. I took what I thought were completely charged batteries and left for the event. About 3 hours later it was time to take a lot of photos. After about 20 shots the camera powered down, and everyone was staring at me. These pictures were taken using manual mode without any flash. Needless to say, I had to run to the gas station across the road to get some batteries. Now switch to a more recent event. Last week I took 4 batteries off the charger to use with my camera. The camera powered up then powered off. My other devices will run on them for awhile, but then they don't use that much energy. Needless to say, I don't even bother to replace my batteries with batteries that aren't coming right off the charger.
  
  A few weeks ago I purchased a set of 4 Duracell rechargeable batteries (AA/HR6/DX1500 NiMH/1,2V/2000 mAh). So far they've been doing quite well, as well as the batteries that came with my charger. However, I'll have to see if they stand the test of time. Afterall, that's the whole purpose of using rechargeable batteries. I'll also pickup a couple of Eneloops.
  
  
• Doesn't last as advertised
  By A1NMF51TVCENI8 on 2006-02-10
  I have a Canon S2 and these batteries last almost as long as the cheap costco non-rechargable ones. They do take upto 8 hours to charge and Amazon is correct about that. Does anyone know of good long lasting 2500 Mah rechargable batteries??
  
  
• Arrived fast, work great
  By A2QZYW3PGRSOA2 on 2006-02-23
  I've used this type of battery before. Long lasting, no problems, I'll buy more!
  
  
• Great NimH!
  By ASHJIEAVZQY5Y on 2007-01-11
  I use these for wireless mice and RC transmitter batteries. They last a long time and so far they've been taking a good charge.
  
  
• Frustrating
  By A2V0K69LXKX7PB on 2007-08-12
  Many times I cursed my camera to be eating batteries but then I tested the Energizer Batteries out of camera and found that they die automatically in as little time as one day. Never belive in Energizer.
  My camera now works with Sony batteries for months.
  
  
• Very poor shelf life, high internal discharge rate
  By AP6SYBW65ROX1 on 2007-08-29
  I've had several sets of these over the past couple of years and I've found that they become virtually unusable after just a few uses. I have taken to carrying 3 extra sets of 4 of these in my digicam case and in several cases I've only gotten 10-20 photos out of the whole batch of 16 batteries, esp. if they've been in the case for a week or so. I thought I must be doing something wrong, or my charger was bad or something, but when I bought some other brands (Rayovac, Tenergy, and Powerex) I found they actually lasted about four times as long as either these Energizers or the equivalent Duracells that I had. I'll not be buying any more of these, or the Duracells either. They were cheap Walmart/Target sets but they're a waste of money.
  
  
• deserves a minus ten . . .
  By A6VXZ1EEPRTLV on 2008-08-28
  Avoid these batteries!!!!!! They are so bad they deserve a rating of minus ten. My experience is similar to many others. Good initial performance, and then after a while these bloody Energizers can't hold a charge. Unfortunately before I discovered how crappy they really are, I bought a bunch of them, for use in my digital cameras and camera flash units. When these babies fail, performance falls like a lead balloon. They might have enough power to operate a remote control unit, but you can forget about powering anything with a major power draw.
  
  Unfortunately Energizer is extremely successful at getting stores to stock this junk. I get real annoyed whenever I see them on display, because it reminds me of all the money I wasted. They seem to be available everywhere, a constant reminder of a disaster. How does a product that is so bad, get such great distribution and remain available for sale? Energizer probably gets off easy, because it takes a while for their batteries to go bad. By then, it's less likely that people will complain or return them. Blasting them wherever I can is like therapy for me. Believe what you hear people, these batteries are terrible!
  
  As an alternative, I have been very satisfied with the performance of Ray-O-Vac Hybrid cells, both the AA and AAA sizes. Take a look at them.
  
  
  
• Good batteries
  By A28PF68Z0U5R1S on 2006-11-09
  I just opened all of them and tried on a toy and it worked fine. Didn't get hot at all as other batteries would.
  
  
• Great batteries
  By ARDESF5VUPJQ0 on 2007-03-06
  I bought these batteries a while back and there were a bit less expensive. Right now they are $20 so you decide if it is worth it for you.
  
  That aside. They are great. I have had them for a year now and they still last just as long as when I bought them. I use them for my digital camera that takes so much battery life. These last longer that the regular non-rechargeable AA batteries.
  
  Make sure you also get a good charger and not those 15-min chargers that burn out you batteries, and you are set.
  
  
• Good for a while, a very little while
  By A1G9MTY6WGQ2VH on 2007-11-25
  I traditionally use rechargeable batteries, so I expect some loss in charge. However, these batteries are the worst I have seen. In one case the batteries were dead by the end of a vacation. In another case, they died after only a week or two of storage. There is something wrong with these batteries. I would avoid them.
  
  

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