1. Introduction
This manual provides essential instructions for the safe installation, operation, and maintenance of the APC SMX120BP External Battery Pack. This unit is designed to extend the runtime of compatible APC Smart-UPS Extended Run SMX-Series Uninterruptible Power Supplies (UPS). It is crucial to read and understand these instructions completely before proceeding with any installation or operation.
2. Safety Information
Observe the following safety precautions to prevent injury and equipment damage:
- Read All Instructions: Carefully read all instructions before installing or operating the external battery pack.
- Heavy Equipment: The SMX120BP unit weighs approximately 140 pounds (63.5 kg). Use proper lifting techniques and assistance to avoid injury during handling and installation.
- Compatibility: This external battery pack is designed for use exclusively with specific APC Smart-UPS SMX-Series models. Refer to the compatibility list in Section 4.1.
- Electrical Hazard: The unit operates at 120VDC. Only qualified personnel should perform installation and maintenance.
- Battery Handling: Batteries are heavy and contain hazardous materials. Handle with care and dispose of according to local regulations.
- Ventilation: Ensure adequate ventilation around the unit to prevent overheating.
3. Product Overview
The APC SMX120BP is an external battery pack designed to provide extended runtime for your critical Smart-UPS applications. It features a 4U rackmount/tower convertible design, allowing flexible deployment in various environments.
3.1 Key Features
- Extended-run battery systems for flexible runtime.
- Compatible with specific APC SMX model UPS units.
- Supports multiple battery pack configurations (up to 10 units) for further runtime extension.
- Spill-proof, maintenance-free sealed lead acid batteries.
- Hot-swappable battery design for easy replacement without interrupting power.
3.2 Front View

Figure 3.1: Front view of the APC SMX120BP External Battery Pack, showing the perforated front panel and APC branding.
3.3 Rear View and Connections

Figure 3.2: Rear view of the APC SMX120BP External Battery Pack, highlighting the proprietary battery connector, power cable, and warning labels for 120VDC and use with APC battery packs only.
4. Setup and Installation
The SMX120BP external battery pack does not function independently; it must be connected to a compatible APC Smart-UPS SMX-Series UPS unit.
4.1 Compatibility
This external battery pack is compatible with the following APC SMX models of UPS:
- SMX2000LV
- SMX2000LVNC
- SMX3000LV
- SMX3000LVNC
- SMX3000HVT
4.2 Physical Installation
The SMX120BP can be installed in a rackmount or tower configuration. Rack mounting brackets are included with the unit.
- Unpacking: Carefully unpack the unit. Due to its significant weight (140 lbs), it is recommended to have assistance or remove the internal batteries before moving the chassis to its final location.
- Placement: Position the external battery pack in its desired rack or tower location, ensuring adequate space for ventilation.
- Mounting: Secure the unit using the provided rack mounting brackets for rack installations.
4.3 Electrical Connection
Connect the external battery pack to the compatible Smart-UPS unit using the proprietary APC battery connector located on the rear of the unit. Ensure the connection is secure.

Figure 4.1: Example of an APC Smart-UPS unit connected to one SMX120BP External Battery Pack.

Figure 4.2: Example of an APC Smart-UPS unit connected to two SMX120BP External Battery Packs, demonstrating extended runtime configuration.
5. Operating the External Battery Pack
Once properly connected to a compatible APC Smart-UPS, the SMX120BP external battery pack operates automatically as an extension of the UPS's internal battery system. It provides additional battery capacity, thereby increasing the overall runtime of the connected UPS during power outages.
- The UPS will automatically detect the connected external battery pack(s).
- The UPS display or management software will indicate the total available runtime, which will be significantly increased by the external battery pack(s).
- No direct controls are present on the external battery pack itself; all operational status and control are managed through the connected UPS.
6. Maintenance
The APC SMX120BP utilizes maintenance-free sealed lead acid batteries. However, periodic checks and eventual battery replacement are necessary.
6.1 Battery Life and Replacement
The average life of the batteries within the SMX120BP is approximately 2 years, depending on environmental conditions and usage. When battery replacement is required, the unit supports hot-swappable battery modules, allowing replacement without powering down the connected UPS.
- Battery Replacement Procedure: To replace batteries, remove the front bezel of the external battery pack. Refer to the detailed instructions provided with the replacement battery modules or the full UPS manual for specific steps.
- Genuine APC Batteries: Always use genuine APC replacement battery cartridges (RBCs) to ensure optimal performance and safety.
- Disposal: Dispose of old batteries responsibly according to local regulations. APC offers a battery recycling program.
7. Troubleshooting
As the external battery pack operates in conjunction with a Smart-UPS unit, most troubleshooting will involve the UPS itself. If you experience issues, consult the user manual for your specific APC Smart-UPS model.
- No Extended Runtime: Ensure the external battery pack is securely connected to the UPS. Verify that the UPS recognizes the external battery pack(s) through its display or management software.
- Unusual Noises or Smells: Immediately disconnect the external battery pack from the UPS and contact APC technical support if you notice any unusual noises, smells, or smoke.
- Physical Damage: Do not operate the unit if it appears physically damaged.
8. Specifications
| Model Number | SMX120BP |
| Brand | APC |
| Battery Cell Composition | Sealed Lead Acid |
| Voltage (Input/Output) | 120 Volts |
| Maximum Power | 1920 Watts |
| Product Dimensions (D x W x H) | 6.75" x 7" x 6.93" (19 x 7 x 17 inches) |
| Item Weight | 140 Pounds (63.5 kg) |
| Form Factor | Rack / Tower Convertible (4U) |
| Connector Type | Proprietary APC battery connector for SMX Series |
| Battery Average Life | 2 years |
| Enclosure Material | Metal |
9. Warranty and Support
9.1 Warranty Information
The APC SMX120BP External Battery Pack comes with a warranty:
- Unit Warranty: 3 years repair or replace (excluding battery).
- Battery Warranty: 2 years for the internal batteries.
Please retain your proof of purchase for warranty claims.
9.2 Technical Support
For technical assistance, troubleshooting, or warranty inquiries, please contact APC customer support. Visit the official APC website for contact information and additional resources.