GE SANYO eneloop 4 Pack AA NiMH Pre-Charged Rechargeable Batteries by Sanyo

GE SANYO eneloop 4 Pack AA NiMH Pre-Charged Rechargeable Batteries

Features

4-pack of 2,000 mAh rechargeable AA batteries for digital cameras, remotes, and more

Pre-charged and ready to use right out of the pack; preserves charge for long periods of time

Extremely slow self-discharge rate maintains 85 percent of capacity after 1 year of storage

Combines best features of AA alkaline ready for use and rechargeable reusable batteries

Can be charged up to 1,000 times including partially without experiencing memory effect

Manufacturer Description
Why Sanyo eneloop?

Sanyo eneloop rechargeables can replace an entire kitchen drawer's worth of dry cell batteries

You already know the benefits of using conventional rechargeable batteries. But Sanyo eneloop batteries have advantages over other rechargeables that put them a step ahead.

Sanyo eneloop batteries are an excellent choice for your rechargeables because:

They can be used right after purchase
They consistenly yield high performance
They have a long shelf life with no loss of energy
They can be used everywhere
They are environmental friendly

Self-Discharge: Why Conventional Rechargeables Don't Cut It

Conventional rechargeable batteries have numerous advantages that make them great to use for your portable electronics. But they also come with certain disadvantages. After purchase, rechargeable batteries have to be charged before they can be used. And once charged, rechargeable batteries lose the stored energy rather fast. The charging takes quite long and rapid chargers are expensive. Not only that, but continuous charging or frequent charge to "top off" the lost energy (without complete discharge) can destroy the battery.

All these negative attributes have one root-cause: self discharge. Self-discharge means that a charged battery slowly discharges itself without any equipment consuming any current. This is the reason for rechargeable batteries being sold in a discharged state. And this is the reason that keeping charged batteries for some time did not make any sense. When you needed them, the energy was gone. Sanyo eneloop batteries have an extremely low rate of self-discharge, which means they hold their stored energy for a very long time--charge your batteries once and put them in your kitchen drawer, and over a year from now you'll still be able to use them right away, without needing to charge them again.

Under the Hood: How eneloop Controls Self-Discharge

How can the self-discharge in the eneloop be so reduced? The self-discharge of Ni-MH batteries is caused by three main reasons:

The chemical decomposition of the cathode
The natural disaggregation of the anode
Impurities of the anode

The chemical decomposition of the cathode has been reduced substantially by the use of a new hydrogen-absorbing superlattice alloy. As an additional benefit the superlattice alloy increases the electrical capacity of the battery and reduces the internal resistance, which allows higher discharge currents than conventional rechargeables. Also, the anode has been strengthened by the improvement of the electrolyte composition, which reduces the natural decomposition by increasing the oxygen over-voltage.

This gives eneloop batteries a number of advantages over traditional alkaline batteries, including up to four times more power when used in a digital camera, high performance even at low temperatures (down to 23 degrees F) during your winter vacation, and a vast cost savings in the long run. The eneloop advantages are even more glaring when compared to typical NiMH batteries: not only are they ready for use right out of the box, but they generally last longer than most NiMH batteries (continuous and frequent recharging can destroy other NiMH models) and save both time and money (traditional NiMH charging is slow when you're in a hurry, while rapid chargers are expensive). All told, you can recharge eneloop batteries up to 1,000 times without experiencing a "memory effect"--just charge the amount you need and you're set.

Product Description
eneloop is a new type of battery, which satisfies your needs and expectation in an unique way. This battery can be used right after purchasing, has a high performance, has a long shelf life with no loss of energy, can be used everywhere, environmentally friendly and easy to use. Unlike disposable batteries which can only be used once and wasteful, eneloop batteries can be recharged replacing 1000 disposable batteries.

Reader Reviews
According to Sanyo, the new eneloop LSD (low self-discharge) NiMH batteries can maintain 85% of its original charge after 1 year of storage. This claim is slightly misleading, because it is based on simulation test at 20 degree C. At higher temperature, the self-discharge rate is likely to be much higher. I have tested five of those AA cells (details are given in my review for the eneloop 4-pack). The average energy loss is about 26% after less than 6 months of storage. This self-discharge rate is about 3 times higher than what Sanyo claimed. However, it is still 6 times lower than that of ordinary NiMH batteries. Therefore I'm in the process of replacing most of my existing rechargeable cells to the Sanyo eneloop. This 8-pack Sanyo eneloop LSD batteries is a better value than two 4-pack. Thanks to lower self-discharge rate, you'll discover a lot more applications for eneloop cells in your house, such as in clocks, remote controls and smoke detectors. But please, don't use them as emergency flash lights batteries in your car, because the higher temperature during summer time will probably nullify the advantage of LSD. [Update on Jan 13, 2007] I have tested six new eneloop AAA cells, dated "2006-06'. The average residue charge is 589mAh, and the freshly charged capacity is 827mAh. This implies a self-discharge rate of 29% in 7 months, which is consistent with the rate for AA cells (26% loss in 6 months). [Update on Jan 29, 2007] The Rayovac "Hybrid" rechargeable NiMH batteries are now available at Walmart, priced at only $[...] for 4-pack of AA or AAA cells. It is also advertised to have low self-discharge rate, but not as low as that for eneloop. The eneloop is supposed to retain 85% charge in 12 months (when stored at 20 degree C), whereas Hybrid is supposed to retain 80% charge in 6 months (no mention of temperature). [Update on June 3, 2007] In my 2-month self-discharge test using four different brands of NiMH cells. Hybrid and eneloop came up neck-and-neck! Room temperature: 60-62 degree F (16-17 degree C). All capacities measured are average of 2-cells. - Sanyo eneloop 2000, purchased Jan 2007. Initial capacity measured: 2070mAh Capacity after 62 days: 1796mAh (-13.2%) (Note: my previous result for eneloop showed -18%, but I repeated the test and it did better this time) - Rayovac Hybrid 2100, purchased Jan 2007. Initial capacity measured: 2155mAh Capacity after 62 days: 1859mAh (-13.8%) - LaCrosse 2000, purchased Jan 2006. Initial capacity measured: 1902mAh Capacity after 62 days: 1417mAh (-26%) - SONY 2300, purchased Sep 2004. Initial capacity measured: 2210mAh Capacity after 62 days: 1309mAh (-41%) So neither eneloop nor Hybrid did as well as advertised, but they are still significantly better than previous generation of NiMH cells. So you can't go wrong with either brand. Comments (53) | Permalink | (Report this)

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Updated on 6-7-2008.