- Provides high power per charge for power-hungry devices
- New recharge AA batteries can be charged up to 250 times
- Batteries for household devices such as digital cameras, toys, remote controls, flashlights and portable audio players.
My original review was about the Energizer '2500mAh' batteries back in 2006. Energizer introduced the new '2300mAh' series in 2010. I have now updated my review to reflect my opinion on the new series.
I had very bad experiences with the previous generation of Energizer 2500mAh rechargeable NiMH batteries, circa 2005. They suffer from rapid self-discharge problem (that is, can't hold a charge for more than a few days even while not in use), and have very limited lifespan (capacity deteriorated badly after just a few dozen cycles). Energizer's initial response was to change the existing series' capacity rating to '2450mAh', as if mere name change is going to solve anything. Around mid-2010, Energizer finally started to introduce a new series to address this problem. The series is named 'Recharge' and it claims to "Hold charge up to one year".
The Energizer New Recharge Batteries featured on this page is the new 'Recharge' series, with a rated capacity of 2300mAh for AA cells. I have tested a set of those new batteries, using my La Crosse BC1000 charger/analyzer. Here are my findings:
Right out of the package, the average remaining capacity is 1684mAh, or 73% of the rate capacity.
After the first Charge/Discharge cycle, the average capacity jumped to 2314mAh
After three more Charge/Discharge cycles, the capacity improved slightly to 2362mAh
After storing the batteries on the shelf for 3.5 months (108 days), the remaining charge is 88% of original capacity.
The above showed that those Energizer 2300mAh cells are indeed low-self-discharge type, similar to the better known Sanyo eneloop.
I have just one remaining doubt: Energizer seems evasive about the battery lifespan, saying only "Charge 100's of times" and "Charge up to 250 more times (than Energizer 2450mAh)". In contrast, Sanyo proudly advertises '1500 cycles' for the eneloop.
On the other hand, the Energizer cell's measured capacity is about 12% higher than that of the eneloop (rated 2000mAh, measured 2100mAh), so even if it can only last for 500 cycles, it is still worthwhile to give it a try. Just make sure that what you get is the new 2300mAh series, not the old 2500/2450mAh junk series.
==========
Old review titled "Shockingly high self-discharge rate!" follows:
==========
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. Kodak also sells a "Pre-Charged" NiMH cell with exactly the same spec as the Rayovac Hybrid.
The bottom line: Low-Self-Discharge NiMH cells are your best choices. There is absolutely no point in taking chances with older generation 2500-2700mAh NiMH cells now.
Buy Energizer New Recharge Batteries, AA, 4-Count Now
I've been using NIMH batteries from SANYO, NEXCELL, POWEREX and AccuPower for over 6 years. Use them for everything from high current drain digital cameras and high-end digital audio recorders to CD players, bathroom scales and flashlights.I rely on two of the excellent MAHA MH-C401FSB smart 2-rate chargers. These charge and monitor each battery independently, not in pairs. Energizer 2500 mAH units were fine for about three months. Then I noticed that devices would be calling for new batteries with little to no use. This has never happened with other AAs NIMH, including those with less than half the advertised capacity. The MAHA charger also started reporting that some of the Energizer AAs were not taking a charge at all.
Kept finding that typically one out of four were the problem. Many of the 32 AA Energizers I bought have had problems. Repeatedly have had one battery run out of charge while others still test very strong. Felt pen dots put on discharged batteries showed it was the same batteries time and time again. Have reverted in some cases to 1600 mAH SANYO OEM batteries put in service in Feb 2001 and those provide longer and more reliable performance!
In my considerable experience with these 2500 mAH AA Energizers they have been a very big disappointment and, regardless of warranty, cannot be relied upon.
Read Best Reviews of Energizer New Recharge Batteries, AA, 4-Count Here
I used to buy excellent Maha rechargable batteries, but finally Energizer attracted my attention. Great price, great capacity. After about 20 recharges batteries are strong and do not show any signs of problems.I use them in old, power hungry and very demanding Olympus E-10 camera. It is known to draw up to one amper of current and to declare batteries empty as far as their voltage goes slightly below 1.2 volts. Considering number of pictures I can take comparing to Maha 2100 MAh batteries, I can say Energizer is very strong performer and 2500MAh is not just a number.
Some users complained about very bad performance for Energizer.
There could be couple things to consider:
make sure you have decent charger: many high capacity NiMh batteries can be destroyed easily with cheap (
0 comments:
Post a Comment