Q: When DS2715 evaluation board is used for charging the NiMH battery, the input is 6V and the output is connected to three NiMH battery packs with rated voltage of 3.6V and maximum charging voltage of 4.5V; after the batteries are fully charged, the 6V voltage is disconnected and then it will be charged again. It takes a long time to stop this charging, and the voltage will exceed 4.5V. Will this cause any damage to the battery?
A: The DS2715 determines whether or not the battery is fully charged based on battery temperature. The battery temperature is sensed by placing a thermistor with negative temperature coefficient close to the battery pack. If the change in temperature exceeds 0.5°C per minute, the DS2715 determines that the battery pack is fully charged. After a short while, if the battery pack is not removed and the temperature becomes constant, the charger will start charging again, until the DS2715 senses a fast increase in temperature. To prevent potential hazard and damage to the battery, please remove it after being fully charged.