Nimh (Nickel metal Hydride) rechargeable batteries will save you money. They can be charged up to 500 times and last longer than alkaline or NiCd batteries. Our Nimh batteries are compatible with most consumer devices and are ideal for digital cameras and flash units, CD players, RC vehicles, PDA’s, portable two-way radios, gameboys, toys, GPS receivers, flashlights, and many more high drain devices. One set of relatively inexpensive Nimh rechargeable batteries can replace thousands of throwaway alkaline batteries.

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What are the primary advantages of Nimh batteries over Alkaline or other rechargeable batteries?

NiMH Batteries Have the Following Advantages :

Last 2-4 times longer than alkaline or standard NiCd batteries
Specifically designed for maximum performance in high-drain electronic devices.
Long life, up to 500-1,000 charge/discharge cycles.
Low cost: less than ½ a penny per recharge compared to up to $1 or more per single-use alkaline
Fast recharge times with new “Rapid Chargers”
Flat discharge curve. Nimh battery will remain in high voltage during 80% of the usage cycle.
No memory effect
Light weight
No toxic chemicals - Friendly to the Environment.

Where can I buy NiMH Rechargeable Batteries?

Star Batteries features top quality Nexcell brand NiMH batteries at some of the lowest prices anywhere. Click the links on the left side of this page to access the order pages or click here to enter our store> STAR Batteries Store

How long can Nimh Batteries last per charge?

	NiMH Batteries	NiCd Batteries	Ordinary Alkaline Batteries
Digital Cameras	400+ Photos	80 Photos	30 Photos
PDA	20 Hours	8 Hours	7 Hours
Game Boy	28 Hours	12 Hours	7 Hours
CD Player	20 Hours	7 Hours	6 Hours

How much can you save using NiMH batteries vs. Alkaline Batteries?

Digital Camera: With one set of 4 AA 2600 mAh NiMH batteries you could take 100,000+ photos and spend around $39 including a fast charger.
To match the performance of the NiMH batteries you would need to get 100 photos per set of Alkaline and would need to purchase:
1000 + packs of 4 pc. Alkaline batteries (100,000 photos/100 photos = 1000 packs) And the Alkaline batteries would cost you around $3000 (1000 x 3)

MONEY SAVED: $2961! ($3000 - $39)

Use NiMH batteries in all your electronic devices for more savings.

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How many times can I recharge my Nimh batteries?

The life of a Nimh rechargeable battery operating under normal conditions is generally around 500 charge-discharge cycles but you may experience more or less depending on the usage conditions and the internal condition of the battery. As a general rule the higher the discharge and charge rates as well as the deeper the discharge between charges the fewer charge/discharge cycles will be obtained. Every time a rechargeable battery goes through a charge and discharge cycle it loses a tiny bit of capacity. The chart on our performance charts page shows a gradual loss of around 3% capacity for each 100 charge cycles. Considering the low replacement cost of Nimh batteries (around .005 cents/charge) the total number of charge cycles obtained may not be cost significant. If your battery eventually stops holding an adequate charge for your application it is time to replace your battery.

There are some general rules you can follow to help your batteries last longer.

· Follow the instructions that come with your charger and use only a charger that is designed to charge Nimh batteries. Use of unqualified chargers could shorten battery life.

· Overcharging can damage your batteries and shorten their life. Star batteries recommends purchasing a high quality "smart" charger. Higher quality chargers can safely charge your batteries in less time using electronic monitoring of the battery condition and utilizing several different protection features to prevent overheat and overcharge.

· Try not to allow your Nimh batteries to completely discharge in your device before recharging them. Most electronic devices including digital cameras will cut off when voltage drops below 1.0V so don't worry about complete discharges in these devices. For other devices like flashlights remove your batteries before they are totally drained. Nimh batteries will generally last for more charge cycles if you charge them after they have been only partially discharged.

· Be careful not to drop your Nimh batteries. Dropping them can cause internal damage.

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My Batteries are brand new and I charged them but they didn't last very long before needing another charge. Is there something wrong with them?

Probably not. Brand new NiMH batteries are difficult to charge when they are brand new or have been sitting unused for more than 6 months. They probably won't accept anywhere near a full charge on the first try. It will take around 3 charge/usage cycles before they reach their rated capacity. After that they will actually continue to gain some capacity (30-50 mAh) through the first 100 charge cycles before they gradually start to lose capacity. You will know when your batteries are accepting a full charge when the charging indicator lights (red) on our smart chargers stay on for the full 3 hours for fully discharged AA batteries.

Tip: Use the conditioning/discharge feature of your smart charger the first 3 or 4 charge cycles to speed up the time to "break in" your new batteries. Charge your batteries normally the first time then push the conditioner buttons on the charger before the next few charges.

My device uses 1.5V “AA” batteries. Will my Nimh batteries work even though they are only 1.2V?

Yes, for most high drain electronic applications Nimh batteries are ideal substitutes and you needn’t worry about the apparent voltage differences. Even though alkaline batteries are rated at a nominal 1.5 volts, they only deliver 1.5 volts when they are fully charged. Alkaline Batteries will drop more linearly from 1.5V to a typical cut off voltage of 0.7V. In fact, over the course of their discharge, alkaline batteries actually average about 1.2 volts. That’s very close to the 1.2 volts of a Nimh battery. However, since the capacity of Alkaline Batteries is measured until cut-off at 0.7V, high-energy consumption rated appliances that commonly cut off at higher voltage cannot fully utilize the energy stored in Alkaline Batteries. This results in wasted energy. During usage, Nimh Rechargeable Batteries will experience a slight voltage drop at first, then will maintain their voltage between 1.2V to 1.0V. The voltage drop is not obvious until it is almost drained, at which point it drops rapidly. The main difference is that an alkaline battery starts at 1.5 volts and gradually drops to less than 1.0 volts. Nimh batteries stay at about 1.2 volts average for about 80% of their discharge cycle for a typical 1C discharge rate (see chart on our performance charts page). There may be uses where there actual voltage difference may be important to you. In the case of a device like a radio, where a higher voltage can mean a stronger signal, a fresh alkaline battery may be more desirable -but more expensive- than a rechargeable Nimh battery. This is also true for a flashlight, which will be temporarily brighter with the initial higher voltage of alkaline cells. These minor differences are probably offset by the much lower cost of operating Nimh batteries. And keep in mind that the alkaline battery only has a higher voltage when it is fully charged. Once it gets to 50% capacity or less, it will be delivering a lower voltage than a Nimh battery.

My camera came with 1800 mAh NiMh batteries. Can I use higher 2600 mAh batteries or will they cause a problem?

Yes you can use any mAh rating higher or lower since the mAh rating refers to the batteries capacity. All AA size NiMh batteries are rated at 1.2V regardless of the mAh capacity. Higher mAh rated batteries will last longer between charges and allows for more photos before they need to be charged. 2600 mAh batteries should last about 40% longer in your camera between charges than 1800 mAh batteries. There is no advantage to buying lower mAh rated batteries other than a little lower cost and somewhat faster recharge times.

Why does the battery display on my device indicate plenty of battery power remaining just before it stops working?

This happens because of the different discharge characteristics between Alkaline and Nimh batteries. Because the voltage of an alkaline battery drops at a very predictable rate it’s possible to estimate the amount of capacity left in an alkaline battery based solely on its voltage. Many consumer electronic devices have a digitally displayed voltage meter to indicate the battery capacity remaining. It is important to note that these meters are displaying battery voltage as an estimate of capacity remaining. When compared with Alkaline Batteries, it is more difficult to determine how much energy remains in a Rechargeable Battery because of its constant operation voltage throughout. These displays will accurately display the voltage of your Nimh batteries but because of the flat discharge characteristics of Nimh batteries they will not accurately estimate the battery capacity remaining. Nimh batteries tend to show less than full capacity when fully charged (around 1.4V) and drop rapidly to about half capacity (around 1.2V) on these digital meters. They will remain close to these readings until just before cutoff. To extend the cycle life of your batteries, change them at first indication of low battery warning.

Tip: Some cameras and devices have a feature to select battery type for the digital battery meter to allow the meter to display accurate battery capacity remaining.

How long can I leave my batteries on trickle charge in the charger?

Since all NiMH batteries will lose some of their charge while sitting unused the trickle charge feature of the smart chargers is intended to keep the battery charge topped off until you are ready to use them. Some manufacturers claim their batteries can take a trickle charge for up to 1 year without damage. You probably would not want to leave them on trickle charge for more than a few weeks since there would be some internal wear on the battery while it is being charged and you would be wasting electricity. You can also easily recharge your batteries if they have lost some of their charge while sitting unused. Some new smart chargers such as the Nexcell NC-60FC have a sleep and wake up mode for trickle charging which allows you to leave the batteries in the charger without worry about overcharge or battery wear.

Why is it important to keep my batteries together in matched sets of 2 or 4?

Simply because you will get better performance from your batteries if you keep them together in matched sets. For example if you have one weak battery in a set it will discharge before the others and result in shorter run times. It is also possible for the weak battery to reverse polarity and damage the battery. In your charger if you have one strong battery it will cause your charger to shut off early resulting in a less than complete charger for the remaining battery in the same charge bank. Some new smart chargers have 4 separate channels to charge each battery individually applying the exact charge needed for each battery.

Can I mix different brands and capacities of batteries in my charger and camera?

No you should not mix battery brands or capacities in your charger or camera for the same reasons stated in the question above.

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Will my Nimh batteries remain fully charged if I store them after charging?

The main disadvantage of Nimh and to a lesser extent NiCd batteries is that they tend to self-discharge fairly rapidly and significantly faster than alkaline batteries. Nimh batteries will begin to lose their capacity after charging when stored. They will lose as much as 1-2% capacity per day and after a few months of storage at room temperature will be mostly discharged. Of course they can be recharged in your charger to regain their capacity. If stored for a very long period without charging they may need a few charging cycles to regain their full capacity similar to when the batteries were new. Store your batteries in a cool dry place to minimize the self discharge effect.

Tip: Purchase a charger that switches to trickle charge after charging and store your batteries in the charger to keep them fully charged and ready for use. Or use the new low discharge type AA NiMH rechargeable batteries which can retain up to 85% of their charge for 12 months.

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Do I need to fully discharge my Nimh batteries before charging to keep them in top condition?

WHAT IS THE “MEMORY EFFECT”?

Memory Effect affects the run time of a traditional (NiCd) Nickel Cadmium Rechargeable Battery. There is some misconception about the word “memory”. Memory is commonly blamed for just about any battery failure known to man. The word ”memory” is derived from “cyclic memory”, meaning that a NiCd battery could remember how much discharge was required on previous discharges and then fail to regain a full capacity recharge. Improvements in battery technology have virtually eliminated this phenomenon. The problem with the modern NiCd battery is not the cyclic memory but the effects of large crystalline formation. (When we refer to memory, we are referring to the formation of crystals.) The active materials (nickel & cadmium) of a NiCd battery are present in crystalline form. When the memory Phenomenon occurs, these crystals grow, forming spike or tree-like crystals that cause the NiCd to gradually lose performance and shut off early . In advanced stages, these crystals may puncture the separator, causing high self-discharge or an electrical short. Crystalline formation only presents a problem if the battery is repeatedly recharged without a periodic full discharge. It is not necessary to discharge a NiCd before each charge. A full discharge to one volt per cell once a month is sufficient to keep the crystal formation under control. Such a discharge/charge cycle is commonly referred to as “exercise”.

If no exercise is applied for several months, the crystals engrain themselves, making it more difficult to dissolve. In such a case, exercise is no longer effective in restoring a battery and “recondition” is required. Recondition is a slow, deep discharge that drains the cell to a voltage threshold below one volt must be discharged to at least 0.6 volts per cell to dissolve the more resistive crystalline build-up. If you use NiCd batteries you should purchase a charger with a "conditioning" function to neutralize the crystalline build-up problem.

Not all NiCd batteries respond well to recondition. A battery that has been in service for over a year and had not been exercised regularly may have a capacity reading that dropped to a low 20%. Even with repeated recondition cycles, the battery may not improve to an acceptable capacity

Nimh Rechargeable Batteries have almost no Memory Effect. Nimh have a different internal chemistry and are not as susceptible to the same “memory” problems as NiCds. In fact Nimh batteries can and should be charged from any discharge state. This is a major advantage of Nimh batteries over NiCd. If your Nimh batteries performance is no longer acceptable use the conditioning feature of your charger to help restore performance.

Tip: To obtain longest cycle life for your Nimh batteries charge them from all discharge conditions including mostly discharged occasionally. This will help keep the internal chemistry of the battery in top condition.

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What does the mAh rating of my batteries mean?

The mAh rating refers to the storage capacity available for a particular battery. A battery with a capacity rating of 2400 mAh could deliver a current of 2400mA for one hour. Higher mAh ratings for the same battery type will generally mean longer run times. This does not apply when comparing different types of batteries. This means that you may not be able to predict how long your electronic device will run just by looking at the capacity rating. When powering high drain electronic devices like digital camera, an alkaline battery will only deliver a small fraction of its rated capacity. For example AA alkaline batteries typically have a capacity rating of over 2500 mAh and AA NiMH batteries have similar ratings of 1800 to 2700 mAh. But when it comes to actually powering an electronic device like a digital camera, the NiMH batteries will often run the device for three or four times as long. A NiMH or NiCd battery is likely to deliver much closer to its rated capacity when it is powering high drain devices. Alkaline batteries have a high rated capacity but they can only deliver their full capacity when the power is used slowly. This means that a NiMH battery with a rated capacity of only 2000 mAh can tale many more photos than an alkaline battery with a rated capacity of 2800.

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Are alkaline batteries better suited to some uses than Nimh rechargeables?

This really depends on what you are using the batteries for. For most high drain electronic devices, like digital cameras, rechargeable batteries will continue to work much longer than alkaline batteries. In fact in devices like digital cameras, Nimh batteries will run on a single charge for 3-4 times as long as they would on an alkaline battery. Alkaline batteries can be the better choice than Nimh or NiCd for some uses. The primary advantage of alkaline batteries is their long shelf life. When a battery is put aside for a period of time, it will lose its stored energy. Alkaline Batteries can hold 80-90% of its charge up to a few years. For Rechargeable Batteries, most of their charge will be gone after a few months and the batteries will need to be recharged. Nimh batteries will work well in flashlights but if the flashlight were to be stored long periods for emergency use then alkaline batteries with their longer shelf life would be the better choice. Alkaline Batteries are more suitable for use in low-energy consumption appliances like digital clocks or remote controls. Rechargeable alkalines typically have an even lower capacity than standard alkaline batteries. They can only be recharged around 50 times and lose capacity relatively rapidly after each charge cycle.

Rechargeable NIMH batteries are the better choice for high drain applications. They last much longer on a single charge and don’t have to be discarded after a single use. Alkaline Batteries are comparatively very expensive

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Are Nimh superior to NiCd (Nickel Cadmium)?

It all depends on which device you are planning to use your batteries in. Nimh batteries are specifically designed to work best in high drain electronic devices such as digital cameras or other portable electronic devices. For most electronic devices it is better to use Nimh batteries than NiCd batteries. Nimh batteries usually have a higher capacity than NiCd batteries of the same size and will last longer before recharging. NiCd batteries can deliver faster discharge rates than Nimh batteries. If you are choosing a battery to drive high torque power tools, then NiCds can outperform Nimh. NiCd’s are also generally more durable than Nimh for industrial type applications that require deep discharge and multiple charge cycles per day. These differences are not relevant when considering power sources for electronic devices like digital cameras or portable music players.

Is there a difference between brands of NiMh batteries or do they perform about the same?

There is very little difference between brands of NiMH batteries however some brands are higher quality. NiMh batteries will last for many years and will probably be lost or become obsolete (as all electronics do) before they wear out. It is probably best to avoid the cheapest brands especially if you are using them in expensive camera equipment since defective batteries can leak or perform poorly.

Are Nimh batteries environmentally friendly?

Definitely yes when compared to other battery power options. Over 2 Billion alkaline batteries are used and disposed of each year in the United States alone. Disposable batteries are certainly a contributor to landfill pollution. Nimh batteries could replace hundreds of alkaline throw-aways. NiCd batteries use Cadmium, a highly toxic heavy metal that can damage the environment if not disposed of properly. (They should be recycled not discarded). Replacing your alkaline or NiCd batteries with Nimh batteries will help keep our environment clean.

Can NiMH batteries explode?

Not likely since NiMH batteries have pressure relief seals that will open if the pressure inside the battery becomes too high. It is very important however to always follow the manufacturers instructions and safety precautions and only use a charger that is designed to charge NiMH batteries.

Where can I find more information on batteries for my Digital Camera?

Try this link for a more detailed discussion of battery selection care and usage specifically for Digital Camera users. http://www.cliffshade.com/dpfwiw/batteries.htm

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Battery FAQ's Last revised: January 2008

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400+ Photos

PDA

Game Boy

CD Player

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How many times can I recharge my Nimh batteries?

My device uses 1.5V “AA” batteries. Will my Nimh batteries work even though they are only 1.2V?

Will my Nimh batteries remain fully charged if I store them after charging?

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Do I need to fully discharge my Nimh batteries before charging to keep them in top condition?

WHAT IS THE “MEMORY EFFECT”?

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What does the mAh rating of my batteries mean?

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Are Nimh superior to NiCd (Nickel Cadmium)?

Are Nimh batteries environmentally friendly?