| Patent application number | Description | Published |
|---|
| 20100176764 | BATTERY PACK AND METHOD OF CONTROLLING THE SAME - A battery pack for an electrically powered tool includes: one or plural secondary batteries connected in series and/or in parallel; a current detection resistor in a current path through which a charge/discharge current flows into each secondary battery; an N-channel charge control FET and an N-channel discharge control FET in the current path so as to control the charge/discharge current; and a controller detecting the charge/discharge current flowing in the current detection resistor and controlling the charge and discharge control FETs based on the detection result. A threshold value indicating an overcurrent detection current with respect to the charge/discharge current is set in advance, and the controller compares the charge/discharge current detected by the current detection resistor with the threshold value, and when the detected charge/discharge current is the threshold value or more, determines that an overcurrent state is detected and turns off the charge and discharge control FETs. | 07-15-2010 |
| 20110080140 | BATTERY PACK - A battery pack includes a current control device that has a thermostat and a positive temperature coefficient device whose resistance increases as the temperature rises connected in parallel, the current control device being inserted into a discharge current path of a battery cell and a protection circuit that detects a voltage of the battery cell, detects an overcharge and over-discharge of the battery cell, and generates an overcharge detection signal and an over-discharge detection signal. In a normal state, a discharge current of the battery cell flows through the thermostat of the current control device. When the discharge current is large enough to damage the battery cell, the thermostat turns off and the discharge current flows through the positive temperature coefficient device. When the positive temperature coefficient device produces heat, a resistance of the positive temperature coefficient device increases and the discharge current is limited or interrupted. | 04-07-2011 |
| 20110089900 | BATTERY PACK - A battery pack includes electric cells connected in series or in parallel between first and second lines, each of the electric cells having a battery cell, a control circuit which performs authentication processing, a communication block which is connected to the control circuit and superimposes a series binary data string on a battery output of the battery cell, and a switching element controlled by the control circuit. The control circuit generates its address. The control circuit of each electric cell transmits the series binary data string including the address to a main body via the communication block and the first and second lines for authentication on each electric cell. The switching element is turned on when the authentication is successful, and charging or discharging is performed. The switching element is turned off when the authentication is unsuccessful, and charging or discharging is banned. | 04-21-2011 |
