Acer 721TX Service Guide - Page 95

Checking Operational Charging: To check operational charging, use a discharged battery pack or a battery pack that has less than 50% of the total power remaining when installed in the computer. Perform operational charging. If the battery status indicator does not turn on, remove the battery pack and let it return to room temperature. Reinstall the battery pack. If the charge indicator still does not turn on, replace the battery pack. If the charge indicator still does not turn on, replace the System board. Then reinstall the battery pack. If the reinstalled battery pack is not charged, go to the next section. Checking the Battery Pack: Battery charging will not start until the Fuel-Gauge shows that less than 95% of the total power remains; with this condition the battery pack can charge to 100% of its capacity. This protects the battery pack from being overcharged or having a shortened life. Do the following: 1. Power off the computer. 2. Remove the battery pack and measure the voltage between battery terminals 1 (+) and 7. See the following figure: If the voltage is still less than +10.0 Vdc after recharging, replace the battery. Chapter 4 87