Compaq 1000 Series Operation And Reference Manual page 67

5. Disconnect the negative (black) battery pack terminal connection.
WARNING: To reduce the risk of short-circuits or arcing, disconnect the
negative (black) battery lead before disconnecting the positive (red) battery lead.
Figure 5-7. Disconnecting the battery pack terminal connections
6. Disconnect the positive (red) battery pack terminal connection.
7. After disconnecting the battery pack terminal connections, pull the
battery pack completely out of the UPS.
WARNING: If hot-swapping the batteries (UPS is in Operate mode), immediately
replace the battery pack. Do not allow terminal connections to contact
conductive materials; do not touch or bring tools in close proximity to terminals.
Battery Maintenance 5-9