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
Gas Gauging
8
SLUUBE8 – September 2018
Copyright © 2018, Texas Instruments Incorporated
General Description
Figure 1-1. bq34210-Q1 CEDV Gas Gauging Operational Overview
1.1.1 CEDV Gas Gauging Operational Overview
The bq34210-Q1 device accumulates the measured quantities of charge and discharge and estimates
self-discharge of the battery. The bq34210-Q1 device compensates the charge current measurement for
temperature and the state-of-charge of the battery. The device also adjusts the self-discharge estimation
based on temperature. The initial battery state-of-charge estimation on first insertion of the battery pack in
the system may display a factor of the true value; the system must go through a full charge and then a full
discharge cycle before the correct full-charge capacity (FCC) is estimated.
The main charge counter,
RemainingCapacity()
(RC) register, represents the available capacity or energy
in the battery at any given time. The bq34210-Q1 device adjusts RC for charge, self-discharge, and other
compensation factors. The information in the RC register is accessible through the I
2
C interface. The
FullChargeCapacity()
(FCC) register represents the initial or last measured full discharge of the battery. It
is used as the battery full-charge reference for relative capacity indication. FCC is accessible through the
I
2
C interface.
1.1.2 Main Fuel Gauge Registers
Remaining Capacity (RC) —
Remaining capacity in the battery
RC
represents the remaining capacity in the battery. The bq34210-Q1 device computes
RC
in units
of mAh.
RC
counts up during charge to a maximum value of
FCC
and down during discharge and self-
discharge to a minimum of 0. In addition to charge and self-discharge compensation, the bq34210-
Q1 device calibrates RC at three low-battery-voltage thresholds, EDV2, EDV1, and EDV0. This
provides a voltage-based calibration to the RC counter.
Design Capacity (DC) —
User-specified battery full capacity