Altronix AL400ULPD8 Dual 12/24VDC Power Supply and Battery Charger
The Altronix AL400ULPD8 is a UL-listed dual-output power supply and integrated battery charger rated for 4A maximum output current. It accepts 115VAC input and delivers regulated 12/24VDC power across eight independent fused outputs — a practical topology for distributed security and access control installations where you need redundant power feeds, equipment isolation, and automatic battery backup without buying separate charger hardware.
Key Features
- Selectable 12/24VDC output: configure once at installation to match your downstream load requirements. No separate SKU inventory needed — one unit covers both voltage families.
- Eight independent fused outputs: each output is protected individually, so a short on one circuit won't cascade to others. Simplifies troubleshooting and reduces nuisance downtime in multi-device deployments.
- 4A per channel maximum: each output can source up to 4 amperes, delivering roughly 48W to 96W per circuit at 12VDC or 24VDC respectively. Sufficient for access control readers, door strikes, proximity card stations, and low-power IP devices over short runs without voltage sag.
- Integrated battery charger and backup: no separate charger module required. The unit automatically manages lead-acid or sealed battery charging, then switches to battery power if AC mains fails — keeping your access or surveillance backbone alive during outages.
- AC Fail supervision alarm output: the unit signals a relay contact or monitored input when mains power drops. Connect this to your control panel or monitoring station to trigger alerts and logging before batteries deplete.
- Low Battery supervision alarm output: provides a second alarm state if battery voltage falls below threshold, giving you time to respond before the supply shuts down entirely.
- Battery Presence detection: the unit monitors whether a backup battery is physically connected and in acceptable condition. Prevents silent failures where a charger appears functional but no backup exists.
- BC300 enclosure: compact DIN-rail or wall-mount form factor fits standard electrical cabinets. Smaller footprint than many competitive dual-output supplies, reducing panel space overhead.
- UL Listed construction: meets North American safety and performance standards — required by code for most commercial security and fire-life-safety installations.
Integration and Deployment Context
The AL400ULPD8 fits into access control systems and power distribution architectures as a mid-capacity, multi-output backbone. It replaces the need to buy one charger and one power supply separately, consolidating BOM and wiring. The eight outputs allow you to feed separate circuits — door strikes on one fuse, readers on another, monitoring relays on a third — without sharing protection. The dual-voltage selectability is useful when you're mixing legacy 12VDC equipment with modern 24VDC devices across the same cabinet.
For larger deployments requiring higher per-channel current or more than eight outputs, consider the Altronix family of industrial power supplies and chargers. For applications needing only a single voltage or lower current per circuit, a more compact single-output unit may reduce cost and footprint.
Why This Matters for Your Decision
If you're designing a security system or access control cabinet where AC mains failure could lock doors, disable readers, or lose recorded video, the integrated charger and multi-output architecture of the AL400ULPD8 reduces component count, simplifies wiring, and provides built-in visibility into battery health and mains status. The eight fused outputs mean you won't have to run series-fused distribution blocks — each load gets its own protected rail.
The tradeoff is that 4A per channel limits the number of simultaneous high-draw devices per output. If you need more than 4A on any single circuit, or more than eight independently protected feeds, you'll need a larger supply unit from the Altronix catalog. Similarly, if your installation uses only a single voltage or requires 12VDC or 24VDC-only operation without selectability, a fixed-voltage model may offer modest cost savings.
Frequently Asked Questions
Q: Can the AL400ULPD8 handle lead-acid batteries larger than a certain capacity?
A: The unit is designed for standard 12V or 24V sealed lead-acid backup batteries. Consult the datasheet or manufacturer documentation for recommended battery AH ratings to ensure proper charge time and protection. Oversizing the battery can extend charge times; undersizing reduces backup runtime.
Q: What happens if the AL400ULPD8 detects a low battery condition?
A: The Low Battery supervision alarm output is activated, sending a signal to your control panel or monitoring system. The supply itself will not shut down immediately — you have time to respond. Continued operation depletes the battery further until mains power is restored or the AC supply automatically shuts down to prevent deep discharge.
Q: Is the AL400ULPD8 compatible with lithium backup batteries?
A: The unit is specified for lead-acid chemistry. Lithium batteries have different charge profiles and voltage curves. Using incompatible battery chemistry may damage the charger or battery — confirm with the manufacturer before attempting substitution.
Q: Can I gang multiple AL400ULPD8 units to increase total output current or channel count?
A: The units are independent supplies. Paralleling the outputs requires careful diode isolation and load sharing design — not a recommended field procedure. For higher capacity, upgrade to a larger single supply or use a dedicated expansion chassis in the Altronix product family.
Q: What is the warranty on the AL400ULPD8?
A: The AL400ULPD8 includes a Lifetime Limited Warranty covering defects in materials and workmanship. Review the warranty document for specific exclusions and claim procedures.
Q: Does the AL400ULPD8 support remote management or SNMP monitoring?
A: The AL400ULPD8 is a standalone analog device. It provides supervised alarm contacts (AC Fail, Low Battery, Battery Presence) for integration into your control panel or monitoring system — no IP connectivity or SNMP. If you need networked power monitoring, look for intelligent UPS or managed PDU solutions outside the Altronix power supply line.
Ted PerryPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The AL400ULPD8 is built for cabinet installations where mains failure isn't an option — think card reader arrays, door access panels, or small NVR systems that need immediate battery takeover. The combination of eight protected outputs and integrated charging eliminates the classic mistake of underspecifying backup, then scrambling to retrofit a charger later.
Technical Highlights:
- Selectable 12/24VDC: one SKU handles both legacy and modern voltage standards, cutting inventory and reducing installation delays when mixing equipment generations.
- Eight independent fused outputs at 4A each: provides 32A total capacity under ideal conditions, but the key benefit is isolation — a shorted reader circuit on output 1 doesn't brown-out your door strike on output 5.
- Integrated battery charger with AC Fail and Low Battery supervision: removes the need to buy and wire a separate charger module. Supervision relay contacts tie directly into your control panel's alarm input, so you get automatic notification before the cabinet goes dark.
- Battery Presence detection: prevents the silent-failure scenario where a battery has physically fallen off or corroded internally, but the supply still reports 'OK' to the outside world.
Deployment Considerations:
- The AL400ULPD8 is fundamentally analog — it has no IP interface, no firmware updates, and no cloud logging. For enterprise environments demanding centralized power monitoring or predictive battery analytics, you'll need to layer in a separate IoT gateway or UPS management system.
- Watch the per-channel 4A limit if your design calls for high-draw solenoid strikes or large LED arrays. A single output will not reliably drive more than one robust 24VDC strike simultaneously without voltage sag. Budget one output per high-current device, or use external distribution blocks downstream.
- The AC Fail alarm contact is dry relay — it requires termination into a monitored security panel input. Don't assume the supply 'talks' to your VMS or BMS on its own.
Deploy the AL400ULPD8 in mid-sized access control cabinets, small-scale surveillance backup nodes, or perimeter security shelters where you need rugged, unsupervised battery backup without network dependencies. It's pragmatic hardware for integrators who respect the 'no network, no problem' principle.
