Texas Instruments bq78350-R1 Technical Reference

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SLUUBD3D–September 2015–Revised September 2018
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CEDV Gas Gauging
Class Subclass Name Format
Size in
Bytes
Min Max Default Unit
Fuel
Gauging
CEDV Cfg
Battery Low
%
Unsigned
Integer
2 0 65535 700 0.01%
Fuel
Gauging
State
Learned Full
Charge
Capacity
Integer 2 0 32767 4400 mAh
Battery Low % should be set to match a capacity value that corresponds to the first or highest voltage
point, EDV2. It should be chosen where the capacity sensitivity to voltage is easily detectable. It is a non-
measured portion of the overall Learned Full Charge Capacity. If the target Battery Low % is changed
in the design, ensure that the initial value of DOD at EDV2 is also adjusted accordingly.
9.1.6 Qualified Discharge
A qualified discharge occurs if the battery discharges from RC ≥ FCC – Near Full to the EDV2 voltage
threshold with the following conditions:
• No valid charge activity occurs during the discharge period. A valid charge is defined as a charge of 10
mAh into the battery.
• No more than 256 mAh of self-discharge or battery load estimation occurs during the discharge period.
• The temperature does not drop below the low temperature thresholds programmed in Low Temp
during the discharge period.
• The battery voltage reaches the EDV2 threshold during the discharge period and the voltage is greater
than or equal to the EDV2 threshold minus 256 mV when the bq78350-R1 detected EDV2.
– When CEDV Gauging Configuration [VFLT_EN] is set, a filter is added to the EDV detection that
is set by CEDV Min Delta V to improve false triggering under pulsed load activity. If the latest
compensated EDV2 voltage changes by more than CEDV Min Delta V from the previously
calculated value, then the previous one is not updated.
• –Current() remains < Overload Current when EDV2 is reached.
• No overload condition exists when EDV2 threshold is reached, or if RC has dropped to Battery Low %
× FCC.
Class Subclass Name Format
Size in
Bytes
Min Max Default Unit
Fuel
Gauging
CEDV Cfg Near Full Integer 2 0 65535 200
mAh or 10
mWh
Fuel
Gauging
CEDV Cfg
Learning
Low Temp
Integer 2 –100 255 119 0.1°C
Fuel
Gauging
CEDV Cfg
Min Delta V
Filter
Integer 2 0 32767 10 mV
The bq78350-R1 sets [VDQ] = 1 in GaugingStatus() when a qualified discharge begins. The bq78350-R1
sets [VDQ] = 0 if any disqualifying condition occurs. One complication may arise regarding the state of
[VDQ] if [CSYNC] is set in CEDV Gauging Configuration. When [CSYNC] is enabled, RC is written to
equal FCC on valid primary charge termination. This capacity synchronization is done even if the condition
RC ≥ FCC – Near Full is NOT satisfied at charge termination.
FCC cannot be reduced by more than FCC Learn Down or increased by more than FCC Learn Up during
any single update cycle. The bq78350-R1 saves the new FCC value to the data flash within 4 s of being
updated.
Class Subclass Name Format
Size in
Bytes
Min Max Default Unit
Fuel
Gauging
CEDV Cfg
FCC Learn
Down
Integer 2 0 65535 256
mAh or 10
mWh
Fuel
Gauging
CEDV Cfg
FCC Learn
Up
Integer 2 0 65535 512
mAh or 10
mWh

Texas Instruments bq78350-R1 Specifications

General

Brand	Texas Instruments
Model	bq78350-R1
Category	Controller
Language	English