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The eneloop advantage
To extend life, eneloop batteries deliver a constant voltage from full charge to depletion. This helps to increase the time between charges.
Unlike dry-cell batteries, which can deliver a high burst of initial voltage before depleting, eneloop is designed to deliver a lower initial voltage which means it might not function in equipment that requires high-voltage batteries. Another example of lower output power might be providing slighter dimmer—but longer lasting—torchlight compared with high-voltage batteries.
Voltage change compared with dry-cell batteries
Under a continuous discharge at 500mA, 25ºC
Longer life at a constant voltage
Unless your appliance specifically demands a high-voltage battery, you can clearly see the advantages of a low-voltage battery in the graph above. You can expect more consistent performance and extended life from an eneloop design.
A digital camera equipped with eneloop can take nearly four-and-a-half times as many shots as one equipped with a standard alkaline dry cell.
Digital camera shots with eneloop vs. dry cell
Longer life and better reliability—eneloop managed about 514 shots.
* Testing conditions at HR-3UTGA with SANYO DSC-S4 digital camera. One picture taken every 20 seconds, LCD on, and flash used every third shot. Results may vary depending on equipment used and other conditions. Comparison made with eneloop battery and comparable SANYO LR6 alkaline dry-cell battery.
Unlike other batteries, eneloop delivers excellent performance at 0ºC and can even be used in temperatures as low as -20ºC.
Discharging characteristics at 0ºC (500mA continuous discharge)
Longer life in cold conditions
For users living in a cold climate, and for those who enjoy outdoor activities such as skiing or camping, there is simply no better-performing battery in cold conditions.
Note: Operation in cold conditions will be shorter than that at room temperature regardless of appliance used.
You can see in the graphic below how eneloop consistently outperforms dry-cell batteries in the most common applications.
Note: the above specifications are based on the theoretical capacity of the battery and the consumption power rate of the equipment. Results may vary greatly depending on the conditions of use, models used, ambient temperature, and equipment condition. Runtime of eneloop product is measured with battery fully charged. Performance time may be shorter if the battery has been left unused for a period of time after being fully charged. All data is approximate. Runtime specifications may be different when eneloop is used with appliances not included in the table. Dry cell was an AA alkaline/manganese; eneloop battery was an AA nickel-metal hydrogen battery. AAA batteries were used for MP3 player and IC recorder.
*1 SANYO DSC-S4 was used in digital camera comparison. One shot was taken every 20 seconds with flash every third frame.
*2 Two AA batteries were used in the torch comparison.
*3 As Manganese batteries are recommended for use in some remote controls and clocks, both test results of Manganese and Alkaline batteries are shown.
Can eneloop be charged up to 1,800 times?
This is an estimation based on test results for battery life according to IEC standards (for the number of times charging and discharging). The number may vary, however, depending on how the batteries are used. Battery life does decrease in relationship with the number of times the battery is recharged.
What’s the difference between 1.5V and 1.2V?
1.5V is the nominal voltage for dry-cell batteries, and nickel-metal hydride batteries (such as eneloop) have a nominal voltage of 1.2V. Dry-cell batteries have a slightly higher voltage than the actual working voltage required by the appliance. Though the nickel-metal hydride battery is 1.2V, nickel-metal hydride batteries are able to provide similar performance to standard dry-cell batteries. Basically, almost all appliances that require a dry-cell battery can also use Ni-MH battery. Please be aware, though, of exceptional cases where only dry-cell batteries can be used.
Is there a size difference between dry-cell batteries and eneloop?
The dimensions of eneloop batteries are based on IEC (International Electrotechnical Commission) standards, and are therefore suited for use in any IEC-approved appliance. However, in some rare cases, you might be unable to comfortably install the batteries. Don’t force the batteries inside as you might damage the container and cause overheating.
What is the difference between “best before” date and “manufacturing date”?
The “best before” date printed on dry-cell batteries refers to the optimal performance guaranteed if you use the battery within this period. This limitation does not apply to eneloop, because nickel-metal hydride batteries can be used anytime if they are electrically charged. For reference, the “manufacturing date” is printed on the package as eneloop batteries are shipped fully charged. Due to the unique low self-discharge feature, if your purchase was within three years of the “manufacturing date”, you can still use them immediately without charging.
What is “memory effect”?
If Ni-Cd batteries and nickel-metal hydride batteries are repeatedly charged before the stored energy is used up, the battery “memorizes” the altered, decreased lifecycle. When you use it the next time, the voltage decreases immediately. Sometimes this causes equipment to shut down. This is called the “memory effect”. The voltage of eneloop is higher than that of conventional nickel-metal hydride batteries and even if the battery is charged excessively, sufficient voltage is maintained and no memory effect occurs. You can recharge the battery as required.
What is “refresh function”?
This function is to remove memory effect. It works by discharging the batteries first and then recharging the batteries to full capacity. Your eneloop battery does not experience memory effect, and so eneloop does not require a refresh function.
What about connecting two or more batteries?
Do not use mix eneloop batteries with batteries of different capacities or different manufacturers. Connecting eneloop with older eneloop batteries is not a problem unless they are drained. We recommend that eneloop batteries be fully charged before use. To ensure satisfactory performance, we recommend using batteries with the same capacities.
My equipment does not work. Why?
It may be due to the following:
Can eneloop be used in underwater lights?
Please do not use eneloop and Panasonic Ni-MH batteries in underwater lights or other airtight appliances. Panasonic Ni-MH batteries feature a gas vent that allows the release of hydrogen when the battery is misused. Gas will not be released under normal usage conditions, but hyper-electric discharge or short circuit can cause internal gas pressure to rise and gas to be expelled. This gas contains hydrogen and sealed devices can’t diffuse the gas, so any source of ignition may potentially cause fire.
My battery gets hot. Is this normal?
Nickel-metal hydride batteries sometimes get as hot as 50ºC (hot to the touch), but this is normal. Our eneloop charger has a temperature protective circuit in case of a temperature rise. After charging is completed, wait until the battery cools off before using it. If the battery gets abnormally hot, it may be dysfunctional.
Where’s the best place to store my eneloop batteries?
You can store them almost anywhere at room temperature, but don’t store them in humid conditions or in direct sunlight. Do not expose them to high temperatures. If stored fully charged, it’s possible to use them within about three years. However, we recommend giving stored batteries a charge once a year for optimal performance.
How should I transport my eneloop batteries?
When carrying or storing batteries for longer periods, avoid direct contact with metallic objects such as keyholders, necklaces, coins, and mobile phones. Also please do not store them in a metallic container as it may cause the product to short circuit. If you do need to use a carry case, we recommend one made from resin.
Can I use another brand’s charger?
We strongly recommend you charge eneloop batteries on Panasonic Ni-MH battery chargers. Panasonic chargers are designed to suit Panasonic batteries to ensure the best performance. We can’t take any responsibility for batteries charged with another brand’s charger. Conversely, we advise against charging other makes of battery on a Panasonic charger.
Can I use a Panasonic charger with other battery brands?
We don’t recommend you use your Panasonic charger to recharge other battery brands, and note also that dry-cell batteries cannot be recharged.
What should I consider when selecting a charger?
Before purchasing a Panasonic charger, please consider the following:
Is it possible to use eneloop worldwide?
Yes, if your Panasonic charger has a function called Auto Voltage to handle any voltage between 100 and 240V. You will likely need a plug adapter for your charger in other countries.
Tips for using eneloop
What is an adapter?
An adapter is a piece of equipment that enables smaller batteries to do the job of larger C and D batteries. Using an adapter, eneloop size AA batteries can power an appliance that requires much larger batteries. The adapter bears no relation to the battery’s capacity, and can be used in many appliances. However, in some cases the adapter will not reach the contact point of the battery compartment. In this situation, do not use the adapter—use size C or D eneloop batteries instead. The adapter is designed for emergency use, and is not intended as an equivalent alternative for C and D size cells.
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