Datasheet

Range: 0 to 65,535 cycles; 65,535 indicates battery
has experienced 65,535 or more cycles.
Granularity: 1 cycle
DesignCapacity() (0x18)
This read-only word returns the theoretical capacity of a
new pack. The DesignCapacity value is expressed in
mAh at the nominal discharge rate.
Output: unsigned integer. Returns the battery ca-
pacity in mAh.
Units: mAh
Range: 0 to 65,535mAh
DesignVoltage() (0x19)
This read-only word returns the theoretical voltage of
a new pack in mV.
Output: unsigned integer. Returns the battery's
normal terminal voltage in mV.
Units: mV
Range: 0 to 65,535mV
SpecificationInfo() (0x1a)
This read-only word returns the specification re
-
vision the bq2040 supports.
ManufactureDate() (0x1b)
This read-only word returns the date the cell was manu
-
factured in a packed integer word. The date is packed
as follows: (year - 1980) ∗ 512 + month ∗ 32+day.
SerialNumber() (0x1c)
This read-only word returns a serial number. This
number, when combined with the ManufacturerName,
the DeviceName, and the ManufactureDate, uniquely
identifies the battery.
Output: unsigned integer
ManufacturerName() (0x20)
This read-only string returns a character string where the
first byte is the number of characters available. The maxi-
mum number of characters is 11. The character string con-
tains the battery manufacturer's name. For example,
“Benchmarq” identifies the battery pack manufacturer as
Benchmarq.
Output: string or ASCII character string
DeviceName() (0x21)
This read-only string returns a character string where the
first byte is the number of characters available. The maxi-
mum number of characters is 7. The 7-byte character string
contains the battery's name. For example, a DeviceName of
“bq2040” indicates that the battery is a model bq2040.
Output: string or ASCII character string
DeviceChemistry() (0x22)
This read-only string returns a character string where
the first byte is the number of characters available. The
maximum number of characters is 5. The 5-byte charac
-
ter string contains the battery's chemistry. For example,
if the DeviceChemistry function returns “NiMH,” the
battery pack contains nickel-metal hydride cells.
Output: string or ASCII character string
ManufacturerData() (0x23)
This read-only string allows access to an up to 5-byte
manufacturer data string.
Output: block data—data whose meaning is as
-
signed by the Smart Battery's manufacturer.
17
bq2040
(MSB) 7 6543210 (LSB)
FLAGS2 DMODE PSTAT CHM CC - OV LTF OC
FLAGS1
∆T/∆t
I
MIN
VQ - VDQ OVLD EDV1 EDVF
Note: - = Reserved
Table 6. Bit Descriptions for FLAGS1 and FLAGS2
Field
Bits
Used Format Allowable Value
Day 0–4
5-bit binary
value
1–31 (corresponds to
date)
Month 5–8
4-bit binary
value
1–12 (corresponds to
month number)
Year 9–15
7-bit binary
value
0–127 (corresponds to
year biased by 1980)