Frequently asked questions (Q & A)
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Q: Why do the 1.2V Ni-MH rechargeable batteries have much better performance at high rate applications than the 1.5V alkaline batteries?
A: NiMH batteries are a spirally wound design compared to a bobbin type design of alkaline batteries. The spirally wound design provides higher electrode surface area therefore the total current can be much higher at a similar kinetics of the battery electrochemical reaction. Due to the same reason, Ni-MH batteries provide higher discharge voltage than alkaline batteries.
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Q: Why should I choose NEXcell Ni-MH rechargeable batteries over other types of batteries?
A: NEXcell NiMH batteries are rechargeable up to 500 to 1000 times which means you can save money compared to rechargeable alkaline batteries with 50 recharges and non-rechargeable batteries. Our NiMH batteries are also designed for power intensive applications such as digital cameras; the batteries will maintain a high and consistent voltage during its discharge cycle, unlike the alkaline batteries whose voltage drops rapidly with high power demand applications. NEXcell batteries have lower impedance than the other brands in the market.
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Q: What is the "no memory effect"?
A: The traditional Ni-Cd batteries can develop memory effect problems if the batteries are discharged at a fixed depth of discharge and then recharged frequently before they have fully drained. "No memory effect" means that you can charge the batteries anytime you like without worrying about their performance and battery life.
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Q: How long will a rechargeable battery will last?
A: The charge holding time of an unused rechargeable battery at room temperature is about one to three months depends on the storage temperature. The best storage temperature range is 10 to 20C. NEXcell batteries are rechargeable up to 500-1000 times depending on discharge and charge current and working condition.
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Q: Why should I pay more for the "higher battery capacity"?
A: The capacity of Ni-MH batteries is rated in "mAh" (mili-ampere hours). If the discharge current is fixed, for example, 1000 mA, the higher capacity means the battery will last longer so you would pay more in price.
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Q: Do I need to charge the new batteries before use them?
A: For storage and safety reasons, the rechargeable Ni-MH batteries are holding minimum charge. In order to reach the peak performance of batteries, you may need to cycle them several times before usage.
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Q: What is conditioning?
A: The conditioning process is used first to drain the charge from the batteries and then charge them. Conditioning can allow batteries to perform at their best standards and eliminate the memory effect of Ni-Cd batteries. For Ni-MH batteries, conditioning is recommended for every ten to twenty charges.
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Q: Batteries should not be left in the charger for a long period of trickle charging. Why can the NEXcell charger can keep the battery in the charger for a longer time?
A: We should not leave the rechargeable batteries in the charger for a long period of time because the batteries will be deteriorated by the trickle charging current after long term charging. We recommend to take the batteries out of the charger when the charging is completed and keep them in a cool location. However, NEXcell chargers do provide lower trickle charging current for longer trickle charging time compared to most other chargers. Our Model 70 charger provides an autostop function of trickle current after batteries have charged to full capacity, and then the batteries will be no current rest for seven days, followed by a 200 mA charge for one hour. The rest/one hour charge cycle will be repeated as long as the battery is still maintained in the charger. The battery will be kept full capacity and without damaged by the trickle charge. This unique design will allow user to store the batteries in the NEXcell charger with full capacity whenever needed.
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Q: Is it normal that the batteries get warm when charging the rechargeable batteries?
A: It is normal that the batteries will increase temperature during charging Ni-MH or Ni-Cd rechargeable batteries because the increase of internal resistance and less energy conversion efficiency from electric energy to chemical energy. We recommend that you leave the lid open during charging to reduce the heat build up inside the charger.
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Q: How long will the rechargeable batteries hold their charge?
A: Ni-MH batteries will self-discharge during stand even left unused. The self-discharging rate is dependant upon the storage temperature. You need to recondition or charge the batteries several times to restore the normal performance. NEXcell brand Ni-MH batteries do provide a much longer shelf life compared to almost all the Ni-MH batteries. |
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| Battery symbols and terminologies |
| V |
Voltage represents the power level of the battery. Just like the height of a reservoir. For Ni-MH or Ni-Cd batteries, they are 1.2V and the alkaline batteries are 1.5V.
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| mAh |
The measurement of battery capacity, mili-ampere hour. The number indicates how long the batteries will last at certain power consumption. The higher mAh batteries will last longer usage time.
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| mA |
The measurement of charging or discharging current, mili-ampere.
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| C |
The rate at which a battery is charging or discharging. Discharging a battery at 0.2C means to drain the battery capacity completely in five hour. Charging a battery at 1C means to charge the battery fully in one hour. 2C charge means using the rate of twice a battery capacity to charge the battery completely in half hour.
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| CmA |
During charging and discharging, CmA is a value indicating current and expressed as a multiple of nominal capacity. Substitute "C" with the battery's nominal capacity when calculating.
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| Other technical terms: |
| Parallel charging of batteries |
Sufficient care must be taken during the design of the charger when charging batteries connected in parallel. Consult NEXcell when parallel charging is required
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| Reverse charging |
Charging with polarity reversed can cause a reversal in battery polarity causing gas pressure inside the battery to rise, which can activate the safety vent, leading to alkaline electrolyte leakage, rapid deterioration in cell performance, battery swelling to battery bursts. Never attempt reverse charging.
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| Overcharging |
Avoid overcharging. Repeated overcharging can lead to deterioration in battery performance and may cause electrolyte leakage.
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| Rapid charging |
To charge batteries rapidly, use the specified charger or charging method recommended by NEXcell and follow the correct procedures.
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| Trickle charging (continuous charging at low current) |
| Carry out trickle charge by applying the current of 0.02 to 0.05 CmA. The correct current value is determined depending on the features and purpose of the equipment. Long term trickle charge is not recommended because it may deteriorate the battery performance. |
