Sony Cycle Energy 2000 mAh Pre-Charged AA Rechargeable Batteries

by Sony

Product Details

• Product Dimensions: 0.5 x 2.5 x 4.5 inches ; 3.2 ounces
• Shipping Weight: 1 pounds (View shipping rates and policies)
• Shipping: Currently, item can be shipped only within the U.S.
• ASIN: B000PHMN44
• Item model number: NH-AA-B4K
• Average Customer Review: 4.4 out of 5 stars  See all reviews (36 customer reviews)
• Amazon Best Sellers Rank:
  • #49 in Electronics > Accessories & Supplies > Batteries, Chargers & Accessories > Household Batteries > Rechargeable
  • #51 in Electronics > Accessories & Supplies > Batteries, Chargers & Accessories > Household Batteries > AA
• Date first available at Amazon.com: June 17, 2003

Product Description

Sony's newest rechargeable battery technology seeks to bridge the gap between regular alkaline batteries and NiMH rechargeable batteries. Cycle Energy rechargeable batteries do not require initial charging and have a very low self discharge rate. They maintain 85 percent of their charge after one year and can be recharged up to 1,000 times. This new technology offers consumers the convenience of a ready-to-use rechargeable battery that is longer lasting.

Customer Reviews

Most Helpful Customer Reviews

31 of 31 people found the following review helpful:

5.0 out of 5 stars Black Cat / White Cat - as long as it catches the mouse...., December 23, 2010

By 

NLee the Engineer (Nashua, NH) - See all my reviews
(HALL OF FAME REVIEWER)    (TOP 10 REVIEWER)   

This review is from: Sony Cycle Energy 2000 mAh Pre-Charged AA Rechargeable Batteries (Electronics)

The Sony Cycle Energy 2000 mAh Pre-Charged AA Rechargeable Batteries are low-self-discharge NiMH type, similar to the more well-known SANYO eneloop. Even their marketing claims sounded almost identical, such as:
- 'Stays 85% charged after 1 year of storage'
- 'Recharge up to 1000 times' (2nd-gen eneloop cells actually claim to achieve 1500 cycles)
- 'Battery Capacity: 2000 mAh'

Naturally, this leads to speculation that SONY Cycle Energy is just Sanyo eneloop under a different wrapper. But apparently it is not the case, based on the following observations:

1. There are minor differences in shapes of positive and negative terminals between those two brands. (See my Customer Images uploaded, and judge for yourself)
2. SONY Cycle Energy cells are made in China, while Sanyo eneloop cells are only manufactured in Japan.

Of course, the real important question is: Do SONY Cycle Energy cells perform just as well as Sanyo eneloop cells? The answer is YES - based on my own test data so far.

I have tested a set of those SONY Cycle Energy AA cells, using my La Crosse BC-900. Here are my findings:
- Right out the box, the average remaining charge in those cells is 1431mAh, or about 70% of rated capacity
- After the first recharge, their average capacity improved to 2032mAh
- After one more recharge/discharge cycle, the average further improved to 2082mAh

Date code imprinted on those SONY cells is '1005', which I interpret as 'May 2010'. That means they were manufactured 7 months ago. Note that similar to eneloop cells, those SONY cells were probably not charged to 100% when they left factory. That explains why they arrived with only 70% of full capacity.

Also note that on each SONY cell it says 'typ 2100mAh, min 2000mAh', while Sanyo cell says 'typ 2000mAh, min 1900mAh'. But in my experience, the measured average capacity of eneloop cells is actually around 2080mAh

So my conclusion is: The electrical characteristics of those SONY cells are practically indistinguishable from that of Sanyo eneloop. Therefore just pick whichever brand is on sale, and you can't go wrong.

[Update on Feb 14, 2011]
Do not confuse this product with the newly introduced Sony Cycle Energy NHAAB4RN 1000 mAh AA Pre-Charged Batteries. The latter is currently priced at about 25% less, but its capacity is 50% lower!

88 of 102 people found the following review helpful:

5.0 out of 5 stars The best battery., July 1, 2008

By 

Chris G. Sebastian (Phoenix, AZ) - See all my reviews
(REAL NAME)   

Amazon Verified Purchase

This review is from: Sony Cycle Energy 2000 mAh Pre-Charged AA Rechargeable Batteries (Electronics)

I am an electrical engineer, and I have tested many, many batteries. The Sony CycleEnery batteries are the best batteries in the world. No other battery has performed as well for me. I highly recommend this battery above all others.

There are two things that make the Sony CycleEnery battery perform so well:

First, if you weigh the Sony battery on a scale, you will find that they are several grams heavier than any of the other brands. This means that there is more material inside, which yields a higher battery life span.

Second, the voltage curve of this battery stays above 1.2 Volts throughout the majority of its life span. The reason this is important is that most electronic devices, such as digital cameras, stop working once the voltage goes below 1.1 Volts. Normal NiMH batteries can have extremely high mAh ratings of 2500 or more -- but you can't actually make use of all those mAh's because the voltage drops below 1.1V relatively early -- this is not the case with the CycleEnergy. Sony has done something to keep the voltage up at 1.2V, so even though the battery is only rated at 2000mAh, they last much, much longer than normal NiMH batteries. I usually get 2-4x the life span out of CycleEnergy batteries, compared to normal NiMH (even the Sony ones!).

To summarize -- these are the best rechargeable batteries on the market right now (2008).

Regards,

~Chris Sebastian

13 of 14 people found the following review helpful:

4.0 out of 5 stars Varying capacities with these Sony's, June 2, 2010

By 

MikeP (Boston, MA) - See all my reviews

This review is from: Sony Cycle Energy 2000 mAh Pre-Charged AA Rechargeable Batteries (Electronics)

I bought two sets of AA and one AAA of these Sony Cycle Energy batteries from a large NY-based and internet camera store during an 8 USD/AA 4-pack deal was posted on slickdeals a couple of weeks ago and I wanted to relay my experience. (Though I do buy most everything else at Amazon!)

All of the batteries were made in China as per prior posts. They all came out of the package with decent voltage (1.3v? I don't recall exactly) but at maybe 50% of the rated charge of 2000 mAH. I personally don't much care since I was going to charge before using anyway. I had encountered a significant variation with 4 of the 8 AA batteries -- 3 from one pack and one from the other pack.

I use the La Crosse BC-700. I did a simple charge of all of the batteries first. That did not bring the charge up near the rated level. On the first 4, I did a single full discharge-charge cycle and they went up as high as almost 2400mAH! Great! The other 4 did not fare as well. A discharge-charge cycle still did not get them up to 2000 mAH, though mostly in the ballpark. I then did a full "refresh" (repeating discharge/charge cycles until no improvement) and 2 made it to 2030 mAH, while the other 2 only 1970mAH.

SUMMARY:
With discharges and refreshes, all of the brand new Sony's were able to get within an acceptable tolerance +/- of the rated charge and some went far beyond the rating. My main point being that not all of these Sony's are created equal. I'm still using a set of Eneloops for my SLR flash, but these are just fine for wireless mice, WiiMotes, toys, and the like.