Compaq IPAQ H3800 Quick reference guide

IPAQH3800 AND H3900SERIES
POCKETPCBATTERY
Document No. 308402-001
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October 2002
Prepared By
Product Marketing
iPAQ Mobile
Solutions
HP/Compa
Computer
Corporation
iPAQ H3800 and H3900 Series Pocket PC Battery
White Paper
Topics include:
• iPAQ Pocket PC Battery Terminology
• Battery Design
• Battery Usage
• Power Management on Devices
• General Usage Tables
• Accessories
• Frequently Aske Questions
Executive Summary
Abstract: This Battery White Paper is esigne to inform customers about the battery
technology use in the iPAQ Pocket PC H3800 an H3900 Series.
This ocument provi es information on how to best configure the iPAQ Pocket PC H3800
an H3900 Series to optimize run time, how various accessories use battery power, an
how to charge your Pocket PC.
iPAQ Pocket PC Battery Terminology
Backlight – Also called Front Light. This is a Cold Cathode Fluorescent Lamp (CCFL)
used to light the display. The backlight is one of the highest consumers of battery
power. The brighter the light the more power is consumed.
Backup Battery – The iPAQ Pocket PC does not contain a separate backup battery. A
portion of the internal main battery is reserved for back-up purposes. When the Pocket
PC is running on the back-up portion of the main battery it is in Battery Reserve.
Battery Capacity – The amount of available battery storage. As lithium ion batteries
get older with use they lose capacity. The battery is designed to retain a minimum of
80% of its original capacity after 300 complete discharge and charge cycles.
Battery Disconnect – This is the state where the battery is prevented from supplying
power to the Pocket PC. Pressing the power button will not turn on the device. The
Pocket PC ships from the factory in this mode. Connecting the Pocket PC to AC power or
pressing the reset switch will activate a battery that has been placed in battery
disconnect mode. A Full Reset is accomplished by placing the Pocket PC in this mode
then re-activating the battery. To prevent over-discharge to the battery the Pocket PC
will protect the battery by entering battery disconnect mode when the battery reserve
has been depleted.

WHITE PAPER (cont.)
Document No. 308402-001
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Battery Reserve – Also called Memory Retention Time. The battery reserve acts as a
backup battery for the Pocket PC. It also determines the length of time that the unit will
retain user data and programs in RAM after the main charge is depleted. While in
Battery Reserve mode the power button cannot be used to turn on the unit. This period
starts after the final warning of low power and ends when the battery disconnects via
software to prevent over-discharge. It is important to connect the Pocket PC to AC
power and recharge the battery before the battery disconnects to prevent loss of user
data and programs.
Full Reset – Also called Hard Reset or Cold Boot. This is accomplished by placing the
battery into Battery Disconnect mode then re-activating the battery. Disconnect the
battery by pressing and holding application buttons 1 and 4 simultaneously while
pressing the reset switch for approximately 5 seconds. A full reset will clear both running
programs and erase user data and programs in RAM. Information such as contacts and
appointments are stored permanently in non-volatile memory or Permanent PIM. A full
reset will return the Pocket PC to the factory default settings but will not erase the
contents of the File Store or a backup of contacts or appointments from Permanent PIM.
Learn Cycle – Also called Battery Calibration. This is a routine that can start when the
battery has completely discharged to the point of disconnecting the battery. As the
battery is charged parameters that are used to monitor or report battery status are
reset. The Learn Cycle routine cannot be started in any other manner.
Normal Reset – Also called Soft Reset or Warm Boot. This is accomplished by pressing
the reset switch located on the bottom of the unit for 2 seconds with the stylus. A
normal reset will clear any running programs but will not erase user data and programs
in RAM.
RAM – Also called Memory. Random-access memory (RAM) is a type of memory that is
written to and erased many times. The user data in RAM can be lost if battery or AC
power is no longer available. RAM in the unit is used for two purposes – storing user
data and programs and running programs. The allocation of memory for each purpose
is managed automatically. This can be viewed by tapping → Start → Settings →
System → Memory .

WHITE PAPER (cont.)
Document No. 308402-001
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ROM - Read-only Memory (ROM) is a type of memory that is written to once and cannot
be overwritten or changed without special utilities. Contents in ROM are not lost when
power is no longer applied. The operating system and other factory default programs
are located in ROM.
Run Time – Also called Battery Life. This is the length of time the device is actively
displaying data or performing a function on battery power.
Shel Li e – This is the amount of time that a battery can stay in storage without
diminishing its capacity to hold a charge.
Standby – Also called Suspend or Off. This is the device state often referred to as
“powered off.” The unit is not being used but battery power is still being consumed to
keep user data and programs in RAM.
Battery Design
Battery Selection
One of the most important decisions in the design of a handheld device is the battery
selection. Trade offs must be made between battery technology run time battery life
weight size and other factors. All of these factors are interdependent and must be
considered at the same time. In a perfect world a battery would have no weight
consume no volume and have endless capacity. However it is obvious that this is not
possible. Over the past few years new technology which offers many advantages for use
in handheld devices have become available.
Lithium Polymer Technology
The battery used in the H3800 and H3900 Series iPAQ Pocket PCs is a 1400 mAH internal
lithium polymer battery. This design combines a battery with the highest energy capacity
in a space-saving package. Lithium Polymer has many advantages over other battery
technologies including no memory that can diminish capacity in other technologies. It is
ideal for devices like Pocket PCs because it is tolerant of conditions in which it is
constantly being re-charged or “topped off.”
Like all batteries lithium polymer batteries lose capacity over time. The batteries
selected for the iPAQ H3800 and H3900 Series product is designed to have at least 80%
of their original capacity after 300 full charge/discharge cycles. During normal usage
many users will not completely discharge the battery before it is recharged. A partial
charge/discharge cycle is not harmful and only in part affects the life of the battery.
For example the user may remove the device from the cradle and check the time for the
next meeting. He/she can carry the device for a few hours and return to the office where
the device is reinstalled into the cradle. At this time only a small portion of the battery
capacity will have been consumed. The device can be connected to AC Power and the
unit will recharge. With this kind of scenario the user can expect several years of
battery life.

WHITE PAPER (cont.)
Document No. 308402-001
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Coin-cell Design Disadvantages
There is another type of battery called a coin cell or dual-battery design. This battery
design is not used in the H3800 or H3900 Series iPAQ Pocket PCs. Typically these are
non-rechargeable lithium ion cells that maintain the RAM state for a specific period of
time when the main rechargeable cell becomes discharged. These systems have certain
disadvantages versus the single battery design.
• Dual-battery design uses a coin cell battery to function as the backup battery. After
the coin cell is used to maintain the RAM state for a period it is discharged by a
certain amount. This results in the backup time being less than that of a new cell.
The coin cell battery must be replaced if used to maintain the system for any
appreciable time period. If a user does not monitor their backup battery they risk
having no backup reserve power when they need it. With a single-battery design
the backup reserve is recharged each time the user cradles the unit or attaches it to
an AC Adapter.
• Dual-battery design (coin cell) is intrinsically less efficient than a single-battery
design because of the need for more circuitry.
Battery Usage
Run Time
The Pocket PC may be used for short periods of time or it can be used continuously. In
either case the run time is the total time of active use. The run time can vary greatly
with many factors and configurations. For example using High Bright setting will affect
run time dramatically. High Bright is the default backlight setting when the unit is
docked and on AC power however it should be used infrequently if the user wants to
extend run time while using battery power.
If the need is to increase capacity the trade off must be to increase size and weight. It is
obvious that there are limits to size and weight so with boundaries set on those factors
run time is only affected by power consumption. In the case of the iPAQ Pocket PC
H3800 and H3900 Series product the run time can be as long as 14 hours in the Power
Save or Backlight Off mode. As stated earlier run time is affected by many factors;
therefore industry standard methods are used to define and measure run time. HP has
chosen to support a standard test suggested by Microsoft for Pocket PC certification. The
test generates activity every few seconds to emulate user input.
Shel Li e
When an iPAQ Pocket PC is shipped from the factory the battery is disconnected so that
the Pocket PC can stay longer on a retailer’s shelf without loss of capacity. After the
user receives the unit and begins to use it the shelf life is not in effect and the user will
not experience shelf life unless the battery is disconnected again. The shelf life of the
H3800 and H3900 Series Pocket PC for a fully charged disconnected battery is
approximately 4 years. If the battery is completely discharged when disconnected the
shelf life is approximately 1 year.

WHITE PAPER (cont.)
Document No. 308402-001
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Battery Status
The battery status charge indicator in the power applet of the unit is displaying the
percentage of the battery charge remaining based on current and temperature (similar to
the gas gauge on your car). The battery status reading is more accurate than the battery
voltage reading because the battery voltage curve changes with battery usage
temperature and age. Utilizing current and temperature allows the power applet to
provide a more detailed and accurate battery status.
Storage o the iPAQ Pocket PC
The H3800 and H3900 will automatically disconnect the battery to prevent over
discharge. After the battery has disconnected the shelf life is approximately 1 year.
Battery Reserve
Data will be maintained for approximately 72 hours while in battery reserve.
LED Indicators
The LED located next to the power button indicates charging and charge status by using
the following signal indicators:
• Flashing amber light – battery is charging
• Solid amber light– battery is charged
Battery Charging
From the point where the iPAQ Pocket PC enters Battery Reserve mode it takes
approximately 3 hours to fully charge the battery.
Constantly discharging and recharging the iPAQ Pocket PC or leaving it in the charger
does not overcharge or damage the battery.
Once the battery reaches a full charge and the LED changes to solid amber the charger
actually stops charging the battery. When the battery drains to a certain level charging
will resume and “top off” the battery and stop again.

WHITE PAPER (cont.)
Document No. 308402-001
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P OWER M ANAGEMENT ON D EVICE
iPAQ Pocket PCs have several power management related settings that can be adjusted
by the user to customize a battery-powered profile.
Backlight Brightness Level
hen the iPAQ Pocket PC is on, the backlight brightness has the most impact on battery
charge of all the power management settings.
• Highest brightness level delivers the shortest battery charge.
• Medium Bright is the default brightness level.
• Lowest brightness level, also called Power Save or Backlight Off mode (no
backlight, reflective screen only) delivers the longest battery charge.
Activating the automatic feature enables the iPAQ Pocket PC to monitor the ambient light
in the usage location and adjusts the backlight brightness to match the environment. This
should improve battery run time, if the use of the iPAQ Pocket PC is in a brightly lit area
for a significant amount of time.
On iPAQ Pocket PCs, the Backlight Brightness Level controls can be accessed from the
Today screen by tapping → Start → Settings → System → Backlight → Brightness .
Note : The brightness level will dim to Medium at the critical battery power warning.
Audio Settings
Audio volume settings have a significant impact on battery performance. The audio
settings can be accessed from the Today screen by tapping → Start → Settings →
Personal → Sounds & Notifications → Notifications . The higher the volume level is
set, the greater the impact will be on the battery.

WHITE PAPER (cont.)
Document No. 308402-001
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G ENERAL U SAGE T ABLES
H3800 Series Battery
The iPAQ Pocket PC has been tested for constant use battery charge using the industry
standard test program for Pocket PCs. This test is part of the suite of tests required for
Pocket PC certification. The constant use test allows for worse case battery charge to be
determined for each iPAQ power management settings group. The table provides
average run times using different backlight setting with and without different expansion
packs using CF and PCMCIA cards as noted below in the table.
H3800 Series Battery
Backlight
Settings iPAQ (unit only)
iPAQ with
PC Card
Expansion
Pack
iPAQ with
PC Card
Expansion
Pack Plus
iPAQ with
Dual PC Card
Expansion
Pack Plus
iPAQ with
CF PC Card
Expansion
Pack Plus
High 4:21 4:02 2:41 4:02 4:41
Medium 5:41 5:21 3:02 4:21 5:22
Low 8:42 6:22 5:51 6:21 6:22
Off Mode 13.48
Note:
 Depending on the device purchased usage time can vary from device to device.
 L110 PC cards were used for the PC Card Expansion Pack and PC Card
Expansion Pack Plus tests. Linksys CF modems were used for the CF Card
Expansion Pack tests.
 All iPAQ Pocket PCs and expansion packs were fully charged at the start of the
test. The Expansion Pack Plus had 920 mAH batteries installed.
 These tests were conducted for 72 hours at room temperatures of approximately
25C degrees.
 The Audio volume setting will affect run time, the higher the volume the shorter
the run time.

WHITE PAPER (cont.)
Document No. 308402-001
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H3900 Series Battery
The table provides average run times using different backlight setting with and without
different expansion packs as noted below in the table.
H3900 Series Battery
Backlight
Settings iPAQ (unit only)
iPAQ with
CF Card
Expansion
Pack
iPAQ with
PC Card
Expansion
Pack
iPAQ with
PC Card
Expansion
Pack Plus
iPAQ with
Dual PC
Card
Expansion
Pack Plus
iPAQ with
CF PC Card
Expansion
Pack Plus
High 4:28 4:21 6:57 7:11 7:50 7:20
Medium 6:42 6:39 10:49 11:00 13:38 11:11
Low 12:37 12:40 19:38 20:04 26:59 20:17
Off Mode 13:42 13:45 22:18 21:52 30:26 22:41
Note:
 Depending on the device purchased usage time can vary from device to device.
 All iPAQ Pocket PCs and expansion packs were fully charged at the start of the
test. The Expansion Pack Plus had 920 mAH batteries installed.
 These tests were conducted for 72 hours at room temperatures of approximately
25C degrees.
 The Audio volume setting will affect run time, the higher the volume the shorter
the run time.

WHITE PAPER (cont.)
Document No. 308402-001
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ACCESSORIES
CF and PC Expansion Pack Plus Battery Information
The CF Expansion Pack Plus and the PC Expansion Pack Plus each have removable
batteries. They each support a 920mA or an 1840mA battery. These are lithium ion
polymer batteries. The battery acts as an extended battery for the Pocket PC. This means
that if the battery has sufficient charge it will provide power to the Pocket PC rather than
the using its internal battery. When the external battery no longer has sufficient power,
then the Pocket PC will switch to its main battery. The extended battery will always drain
first, except on the PC Expansion Pack Plus with PC card inserted.
Extended Battery CF and PC Difference
The CF Expansion Pack external battery always acts as a power source for the iPAQ
Pocket PC, regardless of whether there is a CF card being used. owever, the PC
Expansion Pack battery only acts as a power source for the Pocket PC when there is no
PC card being used. Whenever a PC card is inserted in the Expansion Pack, then the
external battery supplies power to the PC card slot and not to the Pocket PC. Also, the
extended battery is optional on the CF Expansion Pack but is required on the PC
Expansion Pack.
Trickle Charge
Both expansion packs will also trickle charge the main unit battery from the external
battery. This occurs only when the external battery voltage is higher that the main unit
battery. The trickle charge current can be from 0 to 200ma, depending on the voltage
difference. The higher the difference, the greater the current. The trickle charge and the
battery voltages are the same. Therefore, if the main battery is very low and the external
battery is fully charged, then the external battery will trickle charge the main battery until
they have the same voltage. The trickle charge occurs with unit turned on or off. If the
main unit battery is near 0% charge and the external battery is near 100% charge, after
several hours with the Pocket PC off, but attached to the Expansion Pack, the main
battery will be up to 30%-40% charge and the external battery will be down to 50% to
60%. Since the capacities are not the same, both batteries will not reach 50%. It will be
different on the iPAQ Pocket PC 3600/ 3700 models versus the 3800 since their main
batteries also have different capacities. Also, note the PC Card Expansion Pack does not
trickle charge when the unit is on and a PC card is inserted.
Charging
The batteries charge in approximately 2 hours on the Pocket PC. The charge current is
about 500ma for both. owever, if the unit is also charging its battery and the unit is on,
then the charge current is reduced to 100ma on the PC Expansion Pack Plus 300ma on
the CF Expansion Pack Plus. The standalone battery charger also uses 500ma charge
current except on the 1840mA battery where 1000ma is used. It will charge either
battery in about 2 hours. It can charge two batteries in about 2 hours unless both are
1840mA batteries. If both batteries are 1840mA , one will charge in about 2 hours and
the other in about 3 hours.

WHITE PAPER (cont.)
Document No. 308402-001
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Frequently Asked Questions
How do I disconnect a attery?
To disconnect the battery on the iPAQ Pocket PC 3800 and 3900, press and hold down
the 2 outer buttons on either side of the navigation button, and press and hold the reset
switch with the stylus for about 5 seconds. The screen will fade if this is done properly.
(See Reset definition).
What is the run time of the Pocket PC and how was it determined?
The run time of the Pocket PC is up to 14 hours of constant use in Power Save or
Backlight OFF mode. The life is determined using a standard test re uired by Microsoft
for Pocket PC certification.
Actual run time will vary considerably depending on the backlight settings, settings of
alarms and warnings, use of the Media Player, or expansion pack usage.
For example, using maximum brightness at all times will affect run time dramatically.
Maximum brightness is the default backlight setting when the unit is docked and using
AC power, however, it should be used infre uently if the you want to extend run time
while using battery power. This setting should not be used for long periods of time while
traveling to conserve battery power. Enabling the automatic feature of the Brightness
Setting will match the backlight to the surrounding ambient light.
How does the battery power management scenario work?
The battery is a lithium ion polymer cell with 1400 mAH capacity. The battery fully
charges in approximately 4 hours.
If the unit is connected to AC power, within the 72-hour window, the unit will turn on,
then perform a normal reset. The data in RAM will be maintained.
While in use, the battery has 4 warning conditions: Stages 1 to 3 (Low and Critical).
(See: What are Battery Discharge Scenarios?)
What Power Management options are available to improve battery life?
Screen Brightness settings have the most impact on battery life. This means that you
should choose the brightness level that matches your needs, using the High Bright mode
only while connected to AC power.
Tips to lengthen battery life:
Disable audio if this feature is not re uired. Go to tart → ettings → Personal →
ounds & Notifications and disable all sound boxes and put the system volume to
Silent. Under tart → ettings → Personal → ounds & Notifications ,gotothe
Notifications and disable the Flash Light box. This means that there will not be a LED
warning light flashing at each event.