Altronix SMP7PMCTX Supervised Power Supply & Battery Charger
The Altronix SMP7PMCTX is a compact supervised power supply and battery charger engineered for security and access control systems that cannot tolerate downtime. This enclosure-based unit delivers selectable 12VDC or 24VDC output at up to 6A (or 10A at 24V), with integrated battery charging and dual-layer AC/battery supervision. If AC power fails, the unit automatically transitions to battery backup while simultaneously alerting the system to the fault condition — critical for maintaining access control and alarm panel operation during outages.
Key Features
- Dual voltage output (12VDC or 24VDC, selectable): Match the supply to your existing infrastructure without needing separate models. No field rewiring required if you upgrade panel voltage later.
- Up to 6A @ 12VDC or 10A @ 24VDC maximum output current: Sized for single-door access control panels, alarm systems, and small multi-device security deployments. The higher 24V current rating means you can run more devices or longer cable runs with acceptable voltage drop.
- Battery backup charging and monitoring: Continuously charges a connected backup battery (typically 4–12Ah for 24–48 hours of failover runtime). The unit monitors battery health and voltage in real time, detecting weak or failing batteries before an actual outage exposes the problem.
- AC fail supervision with automatic detection: The moment AC power drops, the SMP7PMCTX detects it and can trigger a trouble relay or digital signal to your access control or alarm panel. No manual polling required — the system knows instantly that it's on battery.
- Low battery voltage supervision and notification: If the backup battery voltage sags below a configured threshold (typically 20.5V for 24V systems), the unit signals low-battery to the panel so you can perform a controlled shutdown or alert maintenance before critical function is lost.
- Single regulated output with simplified wiring: One power and ground pair reduces installation complexity compared to dual-output designs. Easier to troubleshoot faults on a single line.
- Compact enclosure form factor: Mounts inside a 19-inch rack, wall-mounted steel cabinet, or vertical DIN-rail enclosure. Footprint is roughly 7×5×3 inches — fits tight spaces without dominating cabinet real estate.
Input & Output Specifications
Input: 115VAC or 230VAC selectable — accommodates both North American and international power standards without requiring a separate step-down transformer. Output regulation: Fixed 12VDC or 24VDC depending on jumper/switch configuration. Regulation tolerance ensures downstream devices (access panels, door strikes, magnetic locks) operate within their specified voltage window, preventing premature relay chatter or sensor false alarms caused by sagging supply voltage.
Integration & Compatibility
The SMP7PMCTX integrates with standard access control power systems and alarm panel backup supplies. It accepts standard 12V or 24V sealed lead-acid batteries or lithium backup packs (verify capacity with your installer). AC fail and low-battery relay outputs can be wired directly to panel trouble inputs on most mainstream brands: security integrators will recognize the standard supervised power pattern. Supervision contacts are dry relays (Form C), so they are independent of the voltage selection and can drive logic at panel inputs without risk of ground loop.
Warranty & Support
Backed by Altronix's Lifetime Limited Warranty — covers defects in materials and workmanship for the life of the original owner. Typical field life exceeds 10 years if the unit is not exposed to moisture ingress or sustained over-current stress.
Frequently Asked Questions
Q: What size backup battery should I pair with the SMP7PMCTX?
A: Battery capacity depends on your load and desired failover duration. A typical access control panel draws 1–2A at 24VDC. For 24 hours of backup, select a 24–50Ah sealed lead-acid battery. The SMP7PMCTX will charge it at a rate that maintains battery health — consult the datasheet for charge current limits.
Q: Can I use the SMP7PMCTX with both 115VAC and 230VAC input in the same installation?
A: The input voltage is selectable via a jumper or switch, not automatic. Configure it once for your facility's AC supply and leave it set. Switching between voltages requires opening the enclosure.
Q: What is the warranty on the SMP7PMCTX?
A: Lifetime Limited Warranty covers manufacturing defects for the original owner. Consumables such as backup batteries are typically excluded.
Q: Does the SMP7PMCTX include a backup battery?
A: No. The unit is the charger and supervisor only — you supply a separate 12V or 24V sealed lead-acid or approved lithium battery sized to your runtime needs.
Q: Can I mount the SMP7PMCTX on a DIN rail?
A: Yes. The compact enclosure supports DIN-rail mounting or wall mounting in a standard electrical cabinet.
Q: Does the SMP7PMCTX work with Milestone, Genetec, or other VMS platforms?
A: The SMP7PMCTX is a power supply, not a camera or recorder. It is not directly integrated with VMS software. However, its AC fail and low-battery relay outputs can be wired to alarm inputs on access control panels or security controllers that feed events to a VMS.
Ted PerryPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The SMP7PMCTX is a no-nonsense supervised power supply — exactly what you specify when access control or alarm panels cannot tolerate a silent failure. The dual-voltage selectable design (12VDC or 24VDC) eliminates SKU proliferation in your spares closet, and the 10A output at 24V is enough headroom for most single-door or small multi-reader systems. The key difference this unit makes is the supervision layer: AC fail detection and low-battery notification relays mean your control panel knows about power faults in real time, not when someone tries to unlock a door and gets a dead strike.
Technical Highlights:
- Battery charging at configurable float voltage: The SMP7PMCTX continuously trickle-charges the backup battery to full capacity and maintains it without overcharging — critical for maximizing battery lifespan. Lead-acid batteries held at constant overcharge voltage fail within 2–3 years; proper float charging extends that to 5+ years.
- AC fail relay closure <100ms: The moment AC power drops, the NO (normally open) AC fail contact closes and signals trouble to the panel. This near-instantaneous detection prevents the panel from sitting on battery for minutes before anyone notices.
- Low-battery threshold supervision: Configurable low-voltage trigger (typically 20.5V for 24V systems) prevents the battery from being completely exhausted. Your panel sees low-battery and can initiate a graceful shutdown, preventing data corruption on access logs or alarm history stored in RAM.
Deployment Considerations:
- Battery sizing is customer responsibility: The SMP7PMCTX does not include a battery — you must calculate runtime requirements and procure a 12V or 24V sealed lead-acid or lithium battery separately. Undersizing the battery means shorter failover duration; oversizing wastes cost and space. Plan for at least 24 hours for most critical access control deployments.
- Input voltage is a static selection: The 115VAC/230VAC input is jumper-selectable, not auto-sensing. Set it at installation and document it. Field mistakes here destroy the transformer — always verify AC input before power-on.
- Relay contact rating: The AC fail and low-battery contacts are dry relays (250mA max). They sink the signal to the panel's logic input — verify that the panel input is compatible with passive relay closure.
Positioning: Deploy the SMP7PMCTX whenever you need supervised, continuous power for access control, alarm panels, or small security device arrays that cannot tolerate AC dropouts. It is standard for integrators specifying redundant or critical-access installations. Skip it only if your panel has built-in battery charging and supervision — in which case you only need a basic power supply.
