Ford F-150 runs poorly when in gear, possible issue after battery and alternator replacement on Ford F-150

Some Ford F-150 owners report experiencing issues with their vehicle running poorly after replacing the battery and alternator, including the transmission revving to about 3500 to 4000 rpms before shifting and a noticeable decrease in pickup, which may indicate a transmission problem. Additionally, some owners find that the engine stalls following a new battery installation, potentially due to incorrect installation or a failure to reset the idle memory properly. It's also noted that checking the battery voltage while the vehicle is running is essential, as readings outside the normal range of 13.5 to 14.8 volts could adversely affect performance. To address these concerns, it is recommended that owners have the transmission system checked, verify the battery installation and idle memory reset, and monitor the battery voltage. If problems persist, consulting a professional mechanic or dealership for a thorough diagnosis is advisable.