About rechargeables

1. What is the difference between alkaline and rechargeable batteries?

Batteries are generally divided into two types—primary and secondary. Primary batteries are used once and thrown away. Secondary batteries can be recharged and used again. Generally speaking, alkaline batteries are primary batteries. Rechargeable batteries contain reversible chemical materials, allowing them to be recharged time and time again.

2. The digital device specifically asks for 1.5V "AA" batteries but would 1.2V NiMH “AA” batteries work for this device?

Yes. You can be sure that NiMH batteries will deliver the high performance needed. Generally AA powered devices will work until the voltage drops to 1.0 - 0.9V. As NiMH Rechargeable batteries have a very flat discharge curve in digital “high drain” devices (i.e. they maintain a consistent voltage for longer), they will perform the same, or even better than ordinary alkaline batteries despite initial lower voltage levels.

3. What are the different types of rechargeable batteries?

There are four different types of rechargeable batteries: NiMH (nickel metal hydride), NiCd (nickel cadmium), Li Ion (Lithium Ion), SLA (Sealed Lead Acid)

The basic components of each system are similar—each consists of a positive electrode (cathode), negative electrode (anode), separator and electrolyte. However, each individual battery chemistry is different, depending on its technology, and each offers different performance characteristics.

4. What is the difference between Nickel Cadmium and Nickel Metal Hydride batteries?

Both types of batteries are rechargeable 1.2 volt systems, and interchangeable in essentially all applications. The key difference is the hydrogen absorbing alloy used in the Nickel Metal Hydride anode (negative electrode) which replaces the cadmium electrode found in the Nickel Cadmium battery. Typically, NiMH batteries have a higher capacity and also considered more environmentally friendly as they do not contain cadmium which is a “heavy metal”.

5. What is memory effect?

The so-called “memory loss” is a loss of battery capacity due to the partial discharging and recharging repetitively without the benefit of a full discharge. The potential for capacity loss due to memory effect occurrence was a problem with the early Nickel Cadmium rechargeable batteries. The probability for memory effect issues is essentially non-existent in today's Nickel Metal Hydride (NiMH) batteries, due to substantial improvements in electrode manufacturing technologies.

Charging NiCd and NiMH batteries for long durations (weeks, months) may result in a slightly lower operating voltage and a lower overall capacity. This is often confused with memory effect, and is corrected in the next standard charge/discharge cycle. The misunderstanding of proper usage and other non-related performance degradation issues are often confused with memory effect, which keeps the myth alive.

6. How many times can I recharge Nickel Metal Hydride batteries?

Cycle life performance depends on a number of factors including battery constructions, usage pattern and environmental storage conditions. NiMH batteries can be more sensitive to prolonged overcharge than NiCd and will have a reduced cycle life if subjected to long periods of extended overcharge. Storage at elevated temperatures will also reduce cycle life. Today’s Energizer NiMH batteries can be charged and discharged hundreds of times in typical usage conditions.

7. What is the relation between capacity and charging time?

The higher the capacity of the battery, the longer it will take to charge it. The majority of battery chargers in the market have constant charging current – therefore by increasing the cell’s capacity the charging time will naturally be longer. As battery capacity has increased, Energizer has continued to bring faster chargers to the market to meet consumer requirement.

8. What is a “smart” charger?

So called “smart chargers” use microprocessor circuitry to monitor the batteries state of charge and terminate the charge when complete. With better charge control, smart chargers can charge the batteries faster without negative consequences. The problem of overcharging is greatly minimized, and therefore more likely to extend battery life.

9. What is trickle charge?

Trickle charge is a low rate charge primarily used to “top-up” a battery to a full state of charge and/or keep at a full charge state prior to usage.

10. Can alkaline batteries be used in an Energizer charger?

No! Standard alkaline batteries are not designed to be recharged and should never be placed in any battery charger. Attempting to charge alkaline batteries will significantly increase the likelihood for leakage to occur.

11. Can I use an old NiCd charger with new NiMH batteries?

The older NiCd chargers were not designed for the substantially higher capacity NiMH batteries and thus may not be capable of providing a high enough charge rate required to obtain a full charge. In order to take full advantage of NiMH performance, a charger specifically designed for the product should be used.

12. Are there devices that rechargeable batteries are not recommended for?

Rechargeable batteries are not recommended for use in devices where the batteries need infrequent replacement. This would include smoke detectors, TV remote controls and flashlights kept on standby for emergency use (unless it is a rechargeable light kept on charge). Rechargeable batteries have a tendency to slowly lose their charge when not in use and may deliver unsatisfactory performance in these devices.

13. Why do batteries become warm while charging?

It is normal for batteries to become warm during the charge cycle due to the energy the charger is putting into the battery. In general, fast charging using higher charge rates will result in increased battery temperatures. Battery temperatures should return to room conditions within minutes after the charging process stops.

14. How long will a NiMH battery hold its charge?

The latest generation Energizer 2450 AA NiMH cells have been improved to the point where, under typical storage conditions, they will still hold approximately 70% of their original charge 6 months later. This will vary considerably for other manufacturer’s cells. The charge loss will also increase at elevated environmental temperatures.

15. How long can I store NiMH batteries?

Typically up to 5 years if stored in standard environmental conditions. To achieve full capacity after extended storage, several slow charge/discharge cycles are recommended to redistribute the electrolyte, etc.

16. How can I test NiMH batteries to see if they’re still good?

Due to their flat discharge profile and recharge ability, it’s difficult to define a simple quality check for NiMH batteries. For fully charged batteries, a battery tester which measures closed circuit voltage can be used as a general guide to determine if the battery is “good” or “defective”. A voltmeter which measures open circuit voltage is not a reliable method for evaluating rechargeable batteries and is not recommended for this purpose.

The most accurate way to measure the performance of rechargeable batteries is to monitor time and operating voltage during controlled discharge.

17. Are NiCd and NiMH batteries considered hazardous waste?

Determination of whether a battery is hazardous or not is dependent on country regulations and the generator of the waste. Please consult your local regulations to determine the status of waste batteries. Regardless of whether the battery is NiCd or NiMH, national collection programs exist. EU Parliament has now set the “Battery Recycling Directive” to ensure batteries are recovered and ultimately recycled.

18. What is the current EU regulation regarding NiCd rechargeable batteries?

The EU Battery recycling Directive has introduced legislation that prohibits retailers selling batteries containing Cadmium from September 2008. As such, all retailers should have removed these products from their shelves.

Energizer rechargeables

1. How many times can I recharge Nickel Metal Hydride batteries?

Cycle life performance depends on a number of factors including battery constructions, usage pattern and environmental storage conditions. NiMH batteries can be more sensitive to prolonged overcharge than NiCd and will have a reduced cycle life if subjected to long periods of extended overcharge. Storage at elevated temperatures will also reduce cycle life. Today’s Energizer NiMH batteries can be charged and discharged hundreds of times in typical usage conditions.

2. Are Energizer NiMH batteries available in all sizes?

Yes, Energizer offers all five core primary battery sizes - AA, AAA, C, D and 9V.

3. Do Energizer NiMH batteries need to be charged before using them for the first time?

Yes, Energizer NiMH batteries are not fully charged upon purchase. However, because they are not fully discharged, either, they should actually charge in less time than would normally be the case.

4. Do Energizer NiMH batteries have to be fully drained before recharging? Do they have a "memory"?

No, there are none of the memory problems with Energizer NiMH like there are with previous NiCd batteries. They can be recharged after a few hours of use or when convenient to the user. If Energizer NiMH batteries have been stored for more than 1 month, they should be charged before use to ensure maximum power.

5. Energizer's highest capacity AA battery is 2650mAh. What does this mean?

NiMH batteries have varying mAh or milliamps ratings. These ratings indicate the power capacity of the battery. The higher the capacity, the longer the battery will last between charges.

6. How many times can Energizer NiMH batteries be recharged?

All Energizer rechargeables can be charged hundreds of times in typical usage.

7. How do you test your chargers and batteries? What makes Energizer batteries any better than other brands?

We have over 500 scientists and engineers working in Westlake, Ohio USA who ensure thorough tests are carried out on all our battery products.

Alongside this, we ensure that all our products comply with all relevant IEC and ANSI guidelines.

8. Why is there such an extensive range of rechargeables on the market? Doesn't this just confuse consumers?

We don't feel that there is a confusing range. In total we have 9 chargers in our rechargeable range which have all been developed from listening to consumers and combining this with the latest technology available.

All Energizer chargers offer a broad range of charging speeds, various numbers of cells that can be charged at any one time, and a variety of other consumer features. As such, we believe the Energizer range offers the breadth and variety of features that shoppers are demanding for today's power hungry devices.

9. Do rechargeable batteries still take days to charge up?

Energizer offers a range of chargers to suit differing needs. Each of our chargers have different charge times ranging from as little as 15 minutes, to 8 hour "overnight" chargers.

10. Isn't the big downside about using rechargeable batteries that they drain very quickly so you have to charge them up really frequently?

Overall, rechargeable batteries perform better than standard alkaline batteries. In high-drain applications (such as in a digital camera) you can typically get up to 4Xx the performance of a standard alkaline battery. However, they will discharge at up t0 0.5 to 1% a day if not in use prior to recharging.

11. Aren't chargers and rechargeable batteries really expensive?

No, they are great value for money. The initial outlay is relatively expensive compared to buying a single pack of batteries, but long-term it is a very economical option for consumers. With today's Energizer Rechargeable batteries capable of being charged hundreds of times and up to 4 times the performance of an alkaline cell (for example in digital cameras), they are a great economical solution for consumers.

12. Can rechargeable batteries be used in any battery operated products?

Yes, however, due to the way some devices are made, they are not always recommended. Rechargeable batteries are ideal for constant, high drain devices.

13. Is there a mechanism on the batteries that tells you when they are about to die/finish? What about when they are fully charged, does the charger tell you this?

Although the "flat discharge curve" on Energizer Rechargeable batteries ensures high performance (up to 4 x alkaline in digital cameras, for example), this consistent voltage means it is not currently possible to put this type of feature on the battery.

Almost the entire range of Energizer chargers have LED's that indicate when the batteries are fully charged, and similarly most devices now have indicators to show when batteries are running low

14. Will the charger keep on charging batteries at the same rate/capacity even in five years time?

No. Rechargeable batteries do lose capacity as they approach their typical shelf life extreme.

15. Do Energizer chargers only take AA and AAA batteries?

All of our chargers charge the AA and AAA batteries which remain the two most popular battery types in Europe.

The new Quattro range now adds the additional capability of charging 9V batteries.

The new Universal charger is designed to take all 5 primary cell sizes - AA, AAA, C, D and 9V.

16. Can Energizer chargers be used abroad?

Most of our chargers have worldwide voltage and therefore can be used abroad with the appropriate plug adapter. Please check specific model for further details.