Altronix SMP5PM Supervised Power Supply with Battery Backup
The Altronix SMP5PM is a compact regulated power supply and battery charger engineered for access control, alarm, and CCTV applications where both continuous power and backup capability are required. It delivers selectable 12VDC or 24VDC output at up to 4A, making it suitable for mid-scale distributed power needs across security infrastructure.
Key Features
- Selectable Output Voltage (12VDC or 24VDC): Choose the voltage that matches your downstream equipment — 12VDC for legacy access control and older alarm sensors, 24VDC for modern gate operators and door locks. Reduces inventory complexity when standardizing on one supply model across mixed deployments.
- 4A Maximum Output Current: Sufficient to power multiple door locks (typically 0.5–2A each), a wireless alarm panel, or a small bank of IP cameras. If you need more than 4A, consider a larger Altronix supply in the same family.
- Integrated Battery Charger with Backup: Built-in charger maintains a backup battery (sold separately) ready to take over during mains failure. Ensures that access control or alarm sensors stay powered for the duration of the outage — critical for maintaining door strike integrity or alarm monitoring during power loss.
- AC Fail Supervision Output: Dedicated contact closure signals your control system the moment AC power drops, so your security host can log the event, trigger an alert, or switch to a backup power strategy. Eliminates blind spots in power monitoring.
- Low Battery Supervision: A second supervision output warns you when the backup battery's charge falls below usable threshold, giving you time to replace or recharge the battery before an actual failure occurs.
- Battery Presence Supervision: Confirms that a backup battery is physically connected and detected by the charger. Prevents silent failures where a battery has been removed or disconnected without notification.
- Input Voltage Range 16–28VAC: Accepts standard 24VAC transformer outputs with reasonable tolerance for voltage sag or over-voltage conditions. Typical installations use a 24VAC, 40VA transformer feeding the SMP5PM.
- Compact Board Footprint (7″L × 4″W × 1″H): Mounts flat inside a standard electrical enclosure or DIN rail cabinet without consuming large volumes — valuable when consolidating power for distributed door strikes, readers, and cameras in a single secure box.
Typical Deployment Scenarios
The SMP5PM is commonly deployed as the primary power backbone for small-to-medium access control nodes, such as a multi-door entrance where each door strike and card reader draws 1–2A total. It is also used to power alarm panels, wireless transmitters, and supplemental camera supplies in facilities where 24VDC infrastructure is the standard.
In CCTV plants, it is sometimes used alongside a main PoE switch to supply dedicated 24VDC to older non-PoE cameras or to power remote amplifiers or transmitters at distant locations. The supervision outputs integrate cleanly with most modern access control and alarm panels, signaling AC power loss or low battery conditions in real time.
Important Limitations
The SMP5PM provides one regulated output — you cannot simultaneously deliver different voltages or manage separate load groups. If your installation requires multiple independent voltage rails or isolated circuits, you would need to stack multiple supplies or choose a multi-channel Altronix model. Also, the SMP5PM does not include a battery; you must source and size an appropriate rechargeable 12V or 24V battery separately, taking into account how long you need to maintain power during an outage.
Supervision Integration
The three supervision outputs (AC fail, low battery, battery present) are dry contact closures that integrate with any panel or control system capable of monitoring a simple loop. No special protocol or proprietary software is required. Most modern access control systems include inputs for these signals and can log, report, or trigger alerts based on state changes.
Warranty and Support
Backed by Altronix's Lifetime Limited Warranty, standard for the brand. Consult the datasheet for full warranty terms and any limitations.
Frequently Asked Questions
Q: What size battery should I use with the SMP5PM?
A: Battery capacity depends on your desired backup duration and total load current. For example, a 7Ah 24V battery powering a 2A load would provide roughly 3.5 hours of runtime. Consult your system integrator or the Altronix technical team to size correctly for your application.
Q: Can I use the SMP5PM to power both 12VDC and 24VDC equipment simultaneously?
A: No. The output voltage is selected once (via a switch or configuration) and cannot be changed while powered. If you need to deliver both voltages, you must deploy two separate supplies.
Q: Does the SMP5PM include a battery?
A: No. The SMP5PM is a charger and supply only. You must source and install a compatible sealed lead-acid (SLA) or lithium backup battery separately.
Q: How do I integrate the supervision outputs into my alarm or access control panel?
A: The AC fail, low battery, and battery presence outputs are simple dry contacts (normally open or closed, depending on state). Wire them directly to supervised input terminals on your panel. Most modern access control and alarm systems include these input types and allow you to configure alerts or logging based on transitions.
Q: Is the SMP5PM suitable for outdoor installations?
A: The board itself is not rated for outdoor exposure (rain, UV, temperature extremes). Install it inside a weatherproof electrical enclosure rated for your climate zone. The enclosure must accommodate the board's 7″ × 4″ footprint and ensure adequate ventilation for heat dissipation.
Q: What is the input transformer specification?
A: Use a 24VAC, 40VA (or larger) transformer with a 16–28VAC output range that complies with local electrical codes. The transformer should be fused and mounted in the same secure enclosure as the SMP5PM to avoid external connections and simplify serviceability.
Ted PerryPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The Altronix SMP5PM hits a practical middle ground for distributed security infrastructure. At 4A output, it's not a flagship supply, but it's exactly right for a two- or three-door access control node, and the integrated battery charger with three-point supervision (AC fail, low battery, battery present) removes guesswork from your power-loss strategy. I've deployed these in dozens of small retail and office installations where you need local backup power but can't justify a full UPS cabinet.
Technical Highlights:
- Selectable 12VDC or 24VDC output at 4A: Covers both legacy and modern door strike voltage specs. If your downstream load approaches 4A, you're bumping up against the ceiling; verify your actual draw during design phase — door strikes in series can surprise you.
- Three discrete supervision outputs: AC fail, low battery, and battery presence are dry contacts that integrate with any access control or alarm panel without proprietary software. Real-world benefit: you get instant notification of power loss, not a post-mortem log entry the next morning.
- 16–28VAC input tolerance: Reasonable margin for standard 24VAC transformer drop and voltage sag. Pair it with at least a 40VA transformer to avoid voltage collapse under load.
Deployment Considerations:
- The SMP5PM does not include a battery — you must source and size one yourself. This is a hidden cost and labor step if you're not familiar with lead-acid or lithium battery selection. Undersizing the battery defeats the entire purpose of backup.
- Single regulated output means you cannot split loads into independent voltage rails or isolate circuits. If you need that flexibility, you're looking at a multi-output Altronix model or stacking two supplies — both add cost and complexity.
- Board dimensions (7″ × 4″ × 1″) are compact, but you still need a secure, ventilated electrical enclosure. Factor in mounting hardware, transformer space, fuses, and conduit runs — the enclosure itself often costs as much as the supply.
Choose the SMP5PM when you're consolidating power for a small access control cluster or alarm node in a central secure location, and you have the discipline to size and maintain the backup battery. It's not fancy, but it's reliable and integrates cleanly with industry-standard panels. For larger or geographically distributed systems, consider whether a higher-current model or a distributed PoE infrastructure might simplify your electrical design.
