Datasheet

= 10 x (EFF% - 74.5 )Charge Efficiency
ERR%
=
0.0125
Efficiency Reduction Rate
TEFF% x 1.6
=
0.0125
Efficiency Temperature Compensation
[ ]
o o
Effective Charge Efficiency (nickel only) = EFF% - ERR% RSOC() - EDOP% - TEFF% T( C) - 25 C
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ë û
Overvoltage Margin +
VOVM
16
bq2060A
www.ti.com SLUS500D –OCTOBER 2001– REVISED OCTOBER 2011
(15)
where
74.5 ≤ EFF% ≤ 100
ERR% is encoded in Efficiency Reduction Rate EE 0x65 according to the following equation:
where
• 0 ≤ ERR% ≤ 3.19 (16)
The Efficiency Drop Off Percentage is stored in 2s complement of percent.
The bq2060A also adjusts the efficiency factors for temperature. TEFF% defines the percent efficiency reduction
per degree C over 25°C. TEFF% is encoded in Efficiency Temperature Compensation EE 0x63 according to the
following equation:
where
• 0 ≤ TEFF% ≤ 1.99 (17)
The bq2060A applies all four charge-compensation factors when the CHEM bit in Pack Configuration is not set
denoting a nickel pack.
where
• RSOC() ≥ EFF% and T ≥ 25°C (18)
If CHEM is set denoting a Li-ion pack, the bq2060A applies only the value coded in Charge Efficiency and makes
no other adjustments for charge acceptance.
Charge Limits and Termination Techniques
Charging Voltage
The 16-bit value, Charging Voltage EE 0x0a–0x0b programs the ChargingVoltage() value broadcast to a Smart
Charger. It also sets the base value for determining overvoltage conditions during charging and voltage
compliance during a constant-voltage charging methodology. It is stored in mV.
Overvoltage
The 8-bit value, Overvoltage Margin EE 0x48, sets the limit over ChargingVoltage() that is to be considered as
an overvoltage charge-suspension condition. The voltage in mV above the ChargingVoltage(), VOVM, that
should trigger a charge suspend is encoded in Overvoltage Margin as follows:
where
• VOVM is between 0 and 4080 mV. (19)
Charging Current
ChargingCurrent() values are either broadcast to a Level 2 Smart Battery Charger or read from the bq2060A by a
Level 3 Smart Battery Charger. The bq2060A sets the value of ChargingCurrent(), depending on the charge
requirements and charge conditions of the pack.
When fast charge is allowed, the bq2060A sets ChargingCurrent() to the rate programmed in Fast Charging
Current EE 0x1a–0x1b.
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Product Folder Link(s): bq2060A