Brief about Connections of a characteristic laptop battery

A laptop battery pack includes a battery of cells, a casing or housing to protect and contain the cells, interconnect means for interconnecting the cells within the casing and conductors running from the interconnected cells to external terminations. The pack also includes a thermally sensitive circuit breaker which serves to disconnect the cells in the event of excessive cell temperatures. The battery pack may include a measuring-resistor strap having two projecting measuring contacts, which forms a portion of the conductors that couples the battery terminals and pack terminals.

A separate current-measuring circuit mounted in the housing provided in the battery pack is coupled to the projecting measuring contacts. A control module in the battery pack receives signals representative of cell voltage, temperature derived from a temperature sensor arranged in thermal contact with the cell and cell current derived by measuring the voltage across a sensing resistor with respect to the external negative voltage. A thermally sensitive circuit breaker provided in the battery pack is in thermal contact with the battery cells and is arranged to disconnect the cell current in case of excessive cell temperature. Usually the laptop battery consists of chemical cells and digital circuit. The success rate of the laptop battery depends on the battery type. Laptop batteries can be repaired but the work is often time consuming.

A characteristic laptop battery connection consists of positive and negative battery terminals, thermistor, clock and data. The positive and negative battery terminals are located at the outer edges of the connector. The positive and negative battery terminals have elasticity of demand to connect the battery outer shell. A thermistor wire is provided at the outside to allow for temperature protection. The most common thermistors are 10 Kilo Ohm NTC or 10kOhm at 20°C or 68°F. It is always better to use the thermistor during charge and discharge to protect the battery against overheating. The inner contacts accommodate the clock and data. Clock and data are usually combined on a one-wire system. The permanent data contained in the battery is programmed into the battery at time of manufacture. The permanent data includes battery type, battery ID number, serial number, battery manufacturer and date of manufacture. The temporary data contained in the battery is acquired during use and consists of cycle count, user pattern and maintenance requirements.

The fix terminal included in some laptop battery is made of flexible material and is adjustable for angle of demand. The fix terminal is selected from the group consisting of 30 degree, 45 degree, 60 degree, 90 degree and 180 degree.Some laptop batteries may have a solid-state switch that is normally in the OFF position. The battery will turn ON when the switch terminal is connected to the ground. Some laptop battery even includes an end-of-battery-life switch which is used to stop the functioning of the battery at a preset capacity level.

The laptop battery is mostly made of two-wire system architecture. The two-wire system is usually configured to the System Management Bus (SMBus). The SMBus is based on a two-wire system using a standardized communications protocol. The SMBus battery has five or more battery connections. The connections of SMBus battery are commonly safe but testing this type of battery appears complicated. In future, intelligent rechargeable battery packs may include some control or monitoring means to provide charge current control during recharge, charge monitoring during discharge and charge, display of battery condition, and transmission of battery condition or other parameters to external equipment.