SIGNAL FOR PRE-CHARGE SELECTION IN LITHIUM CHARGING AND DISCHARGE CONTROL/PRE-CHARGE FUNCTION
First Claim
1. A battery charger operable to charge a battery pack having a plurality of battery cells and at least one data terminal providing an under voltage signal indicative of a voltage of the battery cells relative to a low voltage threshold, the charger comprising:
- a power supply circuit operable to supply a first charge current of a first value and a second charge current of a second value substantially less than the first value; and
a charger control module adapted to receive the under voltage signal from the data terminal of the battery pack and operable to direct the power supply circuit to supply the first and second charge currents based on the under voltage signal,wherein the power supply circuit supplies the first charge current when the under voltage signal is indicative of every one of the battery cells being at or above the low voltage threshold, and the power supply circuit supplies the second charge current when the under voltage signal is indicative of any one of the battery cells being below the low voltage threshold.
1 Assignment
0 Petitions
Accused Products
Abstract
A rechargeable battery pack for a power tool can have a data terminal that provides a signal that is indicative of whether the voltage is below a threshold and can serve as both a pre-charge signal for a charger and as a stop-discharge signal for a power tool. A charger can include a power supply circuit and a voltage detection circuit. A charger control module can receive a signal indicative of the voltage of the battery pack and determine a pre-charge time based on the voltage and can monitor a change in the voltage of the battery pack during the pre-charge operation and stop the pre-charge operation based on the change in voltage and the time period.
-
Citations
32 Claims
-
1. A battery charger operable to charge a battery pack having a plurality of battery cells and at least one data terminal providing an under voltage signal indicative of a voltage of the battery cells relative to a low voltage threshold, the charger comprising:
-
a power supply circuit operable to supply a first charge current of a first value and a second charge current of a second value substantially less than the first value; and a charger control module adapted to receive the under voltage signal from the data terminal of the battery pack and operable to direct the power supply circuit to supply the first and second charge currents based on the under voltage signal, wherein the power supply circuit supplies the first charge current when the under voltage signal is indicative of every one of the battery cells being at or above the low voltage threshold, and the power supply circuit supplies the second charge current when the under voltage signal is indicative of any one of the battery cells being below the low voltage threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A power tool battery pack charger comprising:
-
a charger operable to engage with the battery pack having at least one battery cell and to supply a charge current, the charger including; a power supply circuit operable to supply a charge current of first and second values, the second value being substantially less than the first value; a voltage detection circuit operable to detect a voltage of an engaged battery pack; and a charger control module adapted to receive a signal from the voltage detection circuit indicative of the voltage of the battery pack and operable to control supplying of the charge current from the power supply circuit to the battery pack, the charger control module adapted to determine a time period for a pre-charge operation based on the voltage of the battery pack, the charger control module adapted to monitor a change in the voltage of the battery pack during the pre-charge operation, and the charger control module operable to stop the pre-charge operation as a function of the change in voltage and the time period, wherein the pre-charge operation is characterized by the supplying of the charge current at the second value. - View Dependent Claims (11, 12, 13, 14, 15, 16)
-
-
17. A method of operating a system of power tools having a cordless power tool, a rechargeable battery pack, and a charger, the method comprising:
-
(a) charging the battery pack with the charger, the charging including; engaging a first pair of terminals of the battery pack with the charger, the first pair of terminals communicating with battery cells of the battery pack; engaging a data terminal of the battery pack with the charger; receiving an under voltage signal with the charger at the data terminal, the under voltage signal being indicative of whether a voltage of any one of the battery cells is below a low voltage threshold without identifying any particular battery cell; supplying a charge current of substantially different values to the battery pack with a power supply circuit in the charger based on the under voltage signal detected by the charger, the power supply circuit communicating with the first pair of terminals; and (b) powering the power tool with the battery pack, the powering including; engaging a second pair of terminals of the battery pack with the power tool, the second pair of terminals communicating with the battery cells of the battery pack; engaging the data terminal with the power tool; receiving the under voltage signal with the power tool at the data terminal; and supplying a discharge current from the battery cells to a motor of the power tool based on the under voltage signal received by the power tool, the motor communicating with the second pair of terminals. - View Dependent Claims (18, 19, 20, 21)
-
-
22. A method of charging a power tool battery pack having at least one battery cell with a charger adapted to engage with the battery pack, the method comprising:
-
determining whether to implement a first charging operation using a charge current of a first value or a second charging operation using a charge current of a second value substantially less than the first value; implementing the second charging operation when a voltage of the battery pack is below a low voltage threshold, implementing the second charging operation including; detecting an initial voltage of the at least one battery cell with a voltage detection circuit; determining a time period for the second charging operation as a function of the detected initial voltage; supplying the charge current of the second value to the at least one battery cell with a power supply circuit in the charger; monitoring a voltage of the at least one battery cell; determining a change in the voltage of the at least one battery cell over time during the second charging operation; terminating the second charging operation based on the determined time period and the change in the voltage; and implementing the first charging operation when the voltage of the battery pack is at or above the low voltage threshold. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29)
-
-
30. A method of charging a power tool battery pack having at least one battery cell with a charger adapted to engage with the battery pack, the method comprising:
-
monitoring a signal from the battery pack indicative of either the voltage of any one cell being below a low voltage threshold or the voltage of every cell being at or above the low voltage threshold; determining whether to implement a first charging operation using a charge current of a first value or a second charging operation using a charge current of a second value substantially less than the first value based on the signal from the battery pack; implementing the second charging operation when the signal indicates that the voltage of any cell of the battery pack is below the low voltage threshold, implementing the second charging operation including; supplying the charge current of the second value to the at least one battery cell with a power supply circuit in the charger; monitoring a time duration that the charge current of the second value is supplied; terminating the second charging operation based on the time duration and the signal. - View Dependent Claims (31, 32)
-
Specification