User's Manual
Table Of Contents
- Foreword
- Important Safety Information
- Contents
- About this Document
- Related Publications
- Product Description
- Features
- Specifications
- Air Interface
- Product Functionality
- Contents
- Integration Goal and Objectives
- Customer Problem Isolation
- Wireline and Wireless Communications
- Design Tips for Serviceability
- Environmental Issues
- Regulatory Requirements
- Contents
- Power Supply
- Host Interface
- Power Management
- Antenna Systems
- Hardware Recommendations
- Battery Selection Criteria
- Contents
- Hardware Integration
- Application Software
- Final Assembly
- Installation
- Troubleshooting
- End User Problem Resolution
- Service Depot Repair
- Contents
- Accessories and Options
- Abbreviations and Acronyms
- Desense Overview
- Desense Measurement Techniques
- Preparing the Device Under Test
- Performance Goals
- Methods of Controlling Emissions
- Antenna
- Summary
- FLEX Application Protocol Licensing
- Licensing
July 23, 2002 4-25
CreataLink2 XT Hardware Integrator’s Guide Hardware Integration
Battery Selection Criteria
Battery Selection Criteria
This chapter provides an overview of the current state of available battery
technologies, and some considerations for applying battery technology to a packet
data product. Use batteries only if line power is unavailable.
Select a battery, based on the following factors:
•Cell size
• Internal impedance
• Charging requirements
• Susceptibility to common battery phenomena, such as memory effect or
overcharging
Available Technologies
The four prevailing battery technologies are:
• Nickel-Cadmium (NiCd)
• Nickel-Metal-Hydride (NiMH)
• Lithium Ion (Li-ion)
•Lead-Acid
Nickel-Cadmium
NiCd characteristics are as follows:
• Most mature technology
• Lower energy density (energy/volume) than NiMH or Li-ion
• Available in all cell sizes, including AA, 2/3A, 4/5A, A, 4/3A. This represents
the largest number of packaging options.
• Exhibits a memory effect when not discharged below the lower extent of its
operating voltage. The memory effect reduces the usable capacity of each
battery cell.
• Internal impedance of 25-30 mΩ for each 1.2V cell
• Cell voltages are 1.2V, with multiple cells used to obtain higher operating
voltages.
• Can withstand high current pulses that are characteristic of packet data
applications
• Typical charge method is -∆V (known as negative delta voltage). Negative delta
voltage means charging the battery while waiting for the battery voltage to
peak and enter a slight overcharge condition, where the voltage actually begins
to decrease prior to terminating battery charging. NiCd is the most robust
battery technology available today for non-vehicular applications. NiCd
withstands overcharging, over-discharging, and harsh environments with
reasonable resilience.
• Raw battery cells or battery packs can be purchased from suppliers.
• Typical operating temperature range is –20° C to +50° C
Nickel-Metal-Hydride
NiMH characteristics are as follows:
• Reasonably mature technology with potential for improvements in battery
chemistry and energy density during the next five years
• Higher energy density than NiCd, but lower than Li-ion
• Available in standard sizes AA, 2/3A, 4/5A, A and 4/3A and some prismatic
(rectangular) configurations