Charge
Efficiency
Compensation
Charge
Current
+
Inputs
Remaining
Capacity
(RC)
Discharge
Current
Temperature
Compensation
Self-Discharge
Timer
–
–
≤
+
Full
Charge
Capacity
(FCC)
Discharge
Count
Register
(DCR)
Qualified
Transfer
Temperature, Other Data
Main Counters and
Capacity Reference (FCC)
Outputs
Chip-Controlled
Available Charge
LED Display
Two-Wire
Serial Port
–
+
+
Battery Electronics
Load Estimate
59
SLUUBD3D – September 2015 – Revised September 2018
Copyright © 2015–2018, Texas Instruments Incorporated
CEDV Gas Gauging
Chapter 9
SLUUBD3D – September 2015 – Revised September 2018
CEDV Gas Gauging
9.1
Introduction
The bq78350-R1 features the Compensated End-of-Discharge Voltage (CEDV) gauging algorithm,
capable of gauging a Li-Ion or LiFePO4 battery. The data from the gas gauge is in either mAh or mWh
units based on the 0 or 1 setting of
[CapM]
in
BatteryMode()
, and can be scaled per the
[IPScale]
setting
in
SpecInfo()
.
The operational overview in
illustrates the gas gauge operation of the bq78350-R1.
Figure 9-1. CEDV Operational Overview
The bq78350-R1 accumulates the measured quantities of charge and discharge and estimates self-
discharge of the battery. The bq78350-R1 compensates the charge current measurement for temperature
and state-of-charge of the battery. The bq78350-R1 also adjusts the self-discharge estimation based on
temperature.
9.1.1 Main Fuel Gauge Registers
The main charge counter,
RemainingCapacity()
(RC), represents the available capacity or energy in the
battery at any given time. The bq78350-R1 adjusts RC for charge, self-discharge, and other compensation
factors. The information in the RC register is accessible through the SMBus.
