Educate Me About Batteries

Q: How much performance improvement can I expect using PowerEX NiMH batteries instead of other batteries on my high drain device like a digital camera?

First: PowerEX NiMH batteries are rechargeable up to 500 to 1000 times. This means you can use the batteries over and over again. If you are familiar with "rechargeable alkaline" (which are significantly lower in price), their life is only about 50 recharges.

Second: PowerEx NiMH batteries are designed for power intensive applications. PowerEx NiMH batteries maintain its high power during most of its usage. In other words, PowerEx NiMH batteries maintain a high and consistent voltage during most of its discharge. On the other hand, for alkaline batteries their voltage drops rapidly when used in a power intensive applications such as digital camera. This explains why you can only take 20-30 pictures using alkaline, while you can take up to 150-200 pictures using PowerEx NiMH. (For those who are a bit more technical, take a look at the discharge curve of a PowerEx NiMH battery)

Third: Capacity counts. NiMH batteries are rated in "mAh", acronym for "mili-ampere hours". This number tells you how long the batteries can last under a certain power consumption. The higher the better for this number. For example, PowerEx NiMH AA batteries are rated at 1550mAh. This means its performance will be much better than the competition's 1200mAh, 1300mAh or even 1400mAh.

Forth (A Bit Technical): PowerEx batteries feature an ultra-low impedance compared to other brands of NiMH rechargeable. A battery with a high impedance is almost like a clogged water pipe: power cannot flow from the battery to your device efficiently. In fact, in a high impedance battery, much energy is lost as heat. Generally speaking, a PowerEx 1700mAh AA battery would have a impedance of 15-17mOhm, while a competitor's battery at the same capacity would have a impedance of 25-30mOhm. The end result? PowerEx battery will perform significantly better than a same-rating competition battery.

Q: What do you mean by "no memory effect" on PowerEx NiMH batteries?
Memory is a type of problem that traditional NiCD batteries would develop. You probably have heard that in order to maintain the life and performance of rechargeable batteries, you have to fully drain the batteries before recharging them. Thanks to "memory free" technology featured on PowerEx NiMH batteries, you can charge them anytime you wish, regardless if the batteries are fully drained or not.

Q: What is the difference between PowerEx NiMH batteries and "rechargeable alkaline" batteries?
Recently the market has introduced a new type of supposedly affordable rechargeable alkaline batteries. However, they do not compare with PowerEx NiMH rechargeable technology. The key difference is that rechargeable alkaline batteries can be recharged up to 50 times. PowerEx NiMH can be recharged up to 500 to 1000 times.

Q: Technically speaking, what makes a PowerEx NiMH battery better than other brands of NiMH batteries?
First: PowerEx NiMH batteries are designed with a ultra thin layer of separator. This allows the substantial increase in capacity.

Second: PowerEx NiMH batteries are designed for power intensive applications such as digital cameras. When subjected to heavy power drain, PowerEx NiMH batteries will continue to perform while other brands may not.

	PowerEX New Generation Nickel Metal Hydride Batteries	Traditional Nickel Metal Hydride Batteries	Nickel Cadmium Batteries
Memory Effect (Do you have to fully drain the battery before recharging)	None	None	Yes
Capacity (How long a battery will last)	1700mAh (AA)	1100mAh to 1200mAh	600mAh to 800mAh
Ability to accept trickle charge (Can you leave batteries in the charger)	Yes	No	Yes
Life cycles (How many times can you recharge the batteries)	500-1000 cycles (Depends on discharge & charge rate)	250-350 cycles	500-1000 cycles
Environment Problem	None	None	Yes. Highly toxic
Discharge Characteristics (How well does the battery hold up when used in a high drain device)	Remain above 1.2v/cell at 1C discharge curve during 80% of usage.	Remain above 1.2v/cell at 1C discharge curve during 80% of usage	Remain above 1.2v/cell at 1C discharge curve during 45%-50% of usage

Q: I plan to use the PowerEx NiMH batteries as a backup power. How long will they hold their charge?
This is commonly referred to as the "shelf life" of batteries. For PowerEx NiMH batteries, the shelf life at room temperature is about 70 to 90 days (for those who are a bit more technical, take a look at the charge retention curve). If you are seeking for longer shelf life, you may wish to consider alkaline or non-rechargeable lithium batteries, which are commonly used for memory backups.

Q: Explain the various battery symbols and terminologies.
"mAh": Stands for mili-ampere hours. It measure the capacity of the batteries. For example, a 1000mAh capacity means that the batteries will last for 1 hour if subjected to a 1000mA discharge current.

"V": Stands for voltage. It measure the power of the batteries. For NiMH batteries, they are 1.2V. For alkaline batteries, they are 1.5V.

"C": "C" defines the rate at which a battery is charged or discharged. It is the capacity obtained from a new battery subjected to a constant-current discharge at room temperature. For example, draining a battery at 1C means to drain the capacity of a cell completely in one hour. Likewise, draining a battery at 0.2C means discharge a battery in 5 hours. For nickel-metal hydride cells, the rated capacity is normally determined at a discharge rate that fully depletes the cell in five hours, or 0.2C.