Table of Contents
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able of Contents
Ni-MH Rechargeable Batteries
5.5 Constant Power Discharge Characteristics
5.6 Polarity Reversal During Overdischarge
5.7 Internal Impedance
5.8 Self-Discharge and Charge Retention
5.9 Voltage Depression ("Memory Effect")
6.3 Charging Methods
6.3.1 Duracell's Recommendation:
Three-Step Charge Procedure
6.3.2 Low-Rate Charge
6.3.3 Quick Charge
6.3.4 Fast Charge
6.3.5 Trickle Charge
6.4 Thermal Devices
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Table of Contents
Related Manuals for Duracell Ni-MH
Summary of Contents for Duracell Ni-MH
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Page 1: Table Of Contents
8 Safety Considerations 9 Proper Use and Handling 9.1 Care and Handling 9.2 Transportation 9.3 Waste Management: Recycling and Disposal Ni-MH Rechargeable Batteries 5.5 Constant Power Discharge Characteristics 5.6 Polarity Reversal During Overdischarge 5.7 Internal Impedance 5.8 Self-Discharge and Charge Retention 5.9 Voltage Depression (“Memory Effect”) -
Page 2: Introduction
First introduced to the commercial market in 1988, nickel-metal hydride battery technology is at a very early stage of maturity and manufacturers such as Duracell have identified many opportunities to improve battery performance. These improvements will make DURACELL nickel-metal hydride batteries an attractive power source for 3C devices for many years to come. -
Page 3: Composition And Chemistry
MH + OH - ——> M + H Ni-MH Rechargeable Batteries and AB alloys, of which TiMn DURACELL nickel-metal hydride battery technol- ogy is based on the use of AB alloys offer better corrosion resistance characteris- tics, resulting in longer ability following storage. - Page 4 Thus, charge control vent the build-up of gases and pressure. Duracell rec- ommends that continuous overcharge not exceed C/300 for optimal performance. As shown in Figure 3.3.1, the nickel-metal hydride cell is designed with a discharge and charge reserve in the negative electrode.
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Page 5: Battery Construction
DURACELL standard-sized nickel-metal hydride batteries are constructed with cylindrical and prismatic nickel- metal hydride cells. DURACELL nickel-metal hydride batteries are a sealed construction designed for optimal perfor- mance and maximum safety. The batteries are manufactured to strict quality control standards to ensure reliability and consumer satisfaction and offer such features as: •... -
Page 6: Prismatic Cell Construction
The vent provides additional safety by re- leasing any excess pressure that may build up if the battery is subjected to abusive conditions. Ni-MH Rechargeable Batteries FIGURE 4.3.1 (+) Positive Terminal Safety Vent... -
Page 7: Performance Characteristics
FIGURE 5.2.2 FIGURE 5.2.3 Ni-MH Voltage and capacity of DURACELL DR30 Ni-MH batteries at various discharge temperatures and rates. [Conditions: Charge: 1C to - V = 60mV @ 21 C (70 F)] Temperature: 45 C (113 F) C/5 (0.48A) -
Page 8: Capacity: Effect Of Discharge Rate And Temperature
0 C (32 F) -20 C (-4 F) C (2.4) Discharge Rate (A) Typical capacity of DURACELL DR30 batteries under constant current discharges at various temperatures. [Conditions: Charge: 1C to - V = 60mV @ 21 C (70 F); Discharge to 6.0V]... - Page 9 To minimize the occurrence of polarity reversal, the cells in DURACELL rechargeable batteries have capacities that are “matched” to each other. Device designers can help prevent overdischarge by designing a cutoff voltage for device operation of 1.0 volt per cell.
- Page 10 10 C to 30 C (50 F to 86 F). Ni-MH Rechargeable Batteries FIGURE 5.7.1 depth of discharge. Internal impedance of DURACELL DR30 Ni-MH batteries at various discharge capacities. [Conditions: Charge: C/5 for 7.5 hours; Discharge: C/5; Temperature: 21 C (70 F); Measurements at 1000 Hz] FIGURE 5.8.1 Self-discharge characteristic of Ni-MH cells at various temperatures.
- Page 11 0.85 0.25 Time (Hours) Effects on Ni-MH cell capacity due to repetitive partial discharges [Conditions: Charge: (Cycle #1– #21) = 1C to - V = 12mV. Discharge: Cycle #1 = 1C to 1.0 V, (Cycle #2– #18) = 1C to 1.15V, (Cycle #19 – #21) = 1C to 1.0V; Temperature: 21 C (70 F)] physical characteristics and increase in resistance.
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Page 12: Charging Sealed Nickel-Metal Hydride Batteries
The temperature of the nickel-metal hydride Ni-MH Rechargeable Batteries FIGURE 6.1.1 Charge Input (% of Typical Capacity) Typical charge voltage characteristics of Ni-MH and Ni-Cd batteries. [Conditions: Charge: 1C @ 21 C (70 F) to - V = 10mV/cell] FIGURE 6.1.2... -
Page 13: Techniques For Charge Control
10.0 0 C (32 F) 21 C (70 F) Charge Time (Hours) Charge voltage of DURACELL DR30 Ni-MH batteries at various temperatures. [Conditions: Discharge: C/5 to 6.0V @ 21 C (70 F); Charge: 1C to - V = 60mV] FIGURE 6.1.4 10.0... -
Page 14: Timed Charge
60 C (140 F) is recom- mended. A top-up charge can follow to ensure a full charge. Duracell does not recommend this termina- tion method because of the risk of premature cutoff. this point because it is influenced by ambient tempera- ture, cell and battery design, charge rate, and other factors. -
Page 15: Delta Temperature Cutoff ( Tco)
- V= 60mV dT/dt = 1 C(1.8 F)/min Cycle Number Cycle life and capacity of DURACELL DR30 Ni-MH batteries as a function of charge termination. [Conditions: Charge: 1C; Discharge: C/5 to 6.0V; Cycled to 70% of initial capacity; Temperature: 21 C (70 F)] Sections 6.3.1 to 6.3.5. - Page 16 Charging Sealed Nickel-Metal Hydride Batteries (cont.) 6.3.1 Duracell’s Recommendation: Three-Step Charge Procedure For fast charging and optimum performance, Duracell recommends a three-step procedure that pro- vides a means of rapidly charging a nickel-metal hydride battery to full charge without excessive overcharging or exposure to high temperatures.
- Page 17 Thermal devices in DURACELL nickel-metal hydride batteries are set so the cells are not exposed to temperatures above 91 C (196 F). The inclusion of thermal protective devices in DURACELL nickel-metal hydride batteries helps ensure safe battery operation.
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Page 18: Cycle And Battery Life
At temperatures below 0 C (32 F), the oxygen recombination reaction slows down and the cell is more sensitive to overcharging, thus gas pressure will build up more rapidly. Ni-MH Rechargeable Batteries FIGURE 7.1.1 capacity. The gradual Temperature ( F) -
Page 19: Battery Life
Trickle Charge Discharge Storage, Short Term Storage, Long Term Table 7.2.1 Recommended and permissible temperature limits for operation and storage of DURACELL nickel-metal hydride rechargeable batteries Ni-MH Rechargeable Batteries Cycle life is also affected by the depth of dis- charge. Depending upon the charge termination method,... -
Page 20: Safety Considerations
UL Standard 2054 “Outline of Investigation for Household and Commercial Batteries.” Duracell successfully met all of the test criteria. The tests required under this Standard and the results of the tests on DURACELL cells and batteries are summarized in Table 8.0.1. These tests cover operational and abusive conditions to which batteries may be exposed during their use. - Page 21 Sample is heated by a burner fueled with methane. Table 8.0.1 Results of DURACELL nickel-metal hydride cells and/or batteries tested under UL Standard 2054 test regimes. *Note: These tests were conducted on both individual cells and batteries. Tests not marked with an asterisk were conducted on individual cells only, as deemed adequate by UL to demonstrate safety of both cells and batteries.
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Page 22: Proper Use And Handling
Storage and operation at normal room temperatures is preferred, but wider temperatures can be safely tolerated as discussed in detail in this bulletin. DURACELL nickel-metal hydride batteries are shipped in a partially charged state. Therefore, caution should be exercised to avoid short-circuiting the battery during handling. -
Page 23: Transportation
Ni-MH Rechargeable Batteries Dangerous Goods By Air.” The nickel-metal hydride battery supplied by Duracell is recognized by the regulatory agencies as a “dry battery.” As such, it is not subject to regulation and can be shipped in normal packaging and transported on any mode of transportation without special handling.