Altronix AL62424C 24VDC 0.75A Linear Power Supply with Battery Backup
The Altronix AL62424C is a Class 2 rated linear power supply and charger engineered for 24VDC security applications where power continuity matters. This board-form unit accepts 16/24VAC input and delivers 0.75A at 24VDC with integrated dual 12VDC/4AH sealed lead-acid battery backup — meaning the system switches to battery power instantaneously when AC fails, keeping your access control, door strikes, and lock systems operational during outages. The compact footprint (2.5" × 3" × 1.5") fits inside control panels and enclosure cabinets without eating real estate.
Key Features
- 24VDC output at 0.75A maximum current: Sufficient for single low-draw devices like card readers, magnetic locks, or small relay loads. If your door strike pulls 0.5A, this supply leaves headroom without overload risk. Size your load carefully — once you hit 0.75A, you're at ceiling.
- Dual 12VDC/4AH sealed lead-acid battery backup with instantaneous failover: When AC drops, the switching is immediate — no delay, no brownout. The two 4AH batteries in series deliver 8AH total capacity at 24VDC, giving you roughly 10–12 hours of runtime at minimum load (actual time depends on your connected equipment draw). This is critical for access control systems that must remain live during power incidents.
- 16/24VAC input voltage range: Accepts both 16VAC and 24VAC AC supplies without reconfiguration. This flexibility simplifies panel design if you're working across multiple facilities with different AC supply standards.
- Class 2 rated for safety compliance: Meets NEC Class 2 electrical code — important if you're wiring this into a building where inspection is required. Reduces liability for installers and integrators.
- Compact board form factor (2.5" × 3" × 1.5"): Mounts directly inside control cabinets, DIN-rail enclosures, or wall boxes. No external chassis needed — saves space and installation cost.
- Operating temperature range 0°C to 49°C (32°F to 120°F): Suitable for indoor control rooms and moderate ambient conditions. If your cabinet sits in an unheated warehouse or outdoor enclosure exposed to direct sun, monitor ambient — sustained operation above 49°C will degrade battery life. Plan for cooling if needed.
- Single output configuration: One 24VDC output. If you need multiple isolated outputs or separate voltage rails, this is not your unit.
- Lifetime Limited Warranty: Covers defects in materials and workmanship under normal use. Typical Altronix terms — review the full warranty document for exclusions and battery replacement policies.
Integration and Deployment Considerations
The AL62424C integrates directly into access control and alarm system installations where a single 24VDC supply with battery backup is required. Common applications include electromagnetic door locks, card reader systems, and small relay-based control circuits. Wire the 16/24VAC input to your building AC supply through a disconnect, and connect your 24VDC load directly to the output terminals. The battery charging circuit is built-in — no external charger needed. The unit maintains float charge on the batteries during normal AC operation, ensuring they're ready if power is lost.
One important consideration: the 0.75A output capacity is modest. A standard magnetic door lock strike can draw 0.3–0.6A depending on the solenoid. If you're powering a card reader (typically 0.1–0.2A) plus a strike, you're near or above the limit. Measure your actual load and confirm headroom before installation. If your security application requires multiple simultaneous loads, consider a higher-capacity supply from the Altronix power infrastructure line.
Battery backup runtime depends on load. At 0.3A continuous draw, you'll get significantly longer backup than at 0.75A. Calculate your expected shutdown duration — if your facility typically restores power within 1–2 hours, the 8AH battery capacity (two 4AH units) is comfortable. If blackouts routinely exceed 4 hours, budget for additional external batteries or a larger supply.
Frequently Asked Questions
Q: Can the AL62424C power a 24VDC camera or IP-based access control terminal?
A: Possibly, but check the device's power draw first. If the camera or terminal draws more than 0.75A at 24VDC, the AL62424C will not provide sufficient current. Most PoE-powered IP cameras don't need 24VDC, and 24VDC access panels often draw 0.3–0.5A. Confirm your load before ordering.
Q: How long will the batteries back up my system during a power outage?
A: Runtime depends on your load. At 0.3A draw, expect 12–15 hours from the dual 12VDC/4AH battery set. At 0.75A (maximum), runtime drops to 5–8 hours. These are estimates — actual performance varies with battery age, temperature, and load profile. Test the runtime in your environment before relying on it for critical applications.
Q: Is the AL62424C compatible with my existing 24VDC door lock and card reader system?
A: Yes, if your system is DC-powered and your total load does not exceed 0.75A. The AL62424C outputs 24VDC, which is the standard for most electromagnetic lock strikes and proximity card readers. Wire the output terminals to your existing system load. If your load is AC-powered (less common but possible), this supply will not work.
Q: Does the AL62424C require any special maintenance?
A: Minimal. Check battery terminals annually for corrosion. Sealed lead-acid batteries typically last 3–5 years under float-charge conditions. If the unit is in a hot enclosure, lifespan will shorten. Keep the board clean and ensure ventilation around the unit to prevent thermal buildup. Replace batteries when they no longer hold a charge during test power loss.
Q: What happens if I exceed the 0.75A output rating?
A: The internal protection circuit will limit or shut down the output to prevent damage to the supply. Your connected devices will lose power. Do not rely on the AL62424C for loads above 0.75A — undersizing the supply creates an unreliable system. Size your supply to your actual load plus margin.
Ted PerryPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The Altronix AL62424C is a workhorse for access control and alarm system integrations where you need 24VDC continuity through a power loss. The 0.75A output with dual 12VDC/4AH sealed lead-acid battery backup is purpose-built for single-device loads — card readers, magnetic strikes, and relay-driven door controls — with zero-delay failover. For most small-to-mid security installations, this is the right answer.
Technical Highlights:
- Instantaneous battery failover on AC loss: No dropout window — the batteries engage immediately when AC power drops. This matters for access control systems where even a 50ms interruption can lock users out or trigger false alarms.
- Dual 12VDC/4AH sealed lead-acid with integrated float charger: 8AH total capacity provides 10–12 hours of backup at light load (0.3A), shrinking to 5–8 hours at maximum 0.75A draw. The float-charge circuit keeps batteries conditioned during normal operation — they're always ready. Sealed chemistry means no maintenance acid checks or watering, reducing liability for installers.
- 16/24VAC input flexibility: Accommodates both 16VAC and 24VAC supplies without jumper changes or reconfigurations. If your facility retrofits from 16VAC to 24VAC infrastructure, or if you're deploying across multiple sites with different AC standards, this saves configuration headaches.
Deployment Considerations:
- Load headroom is tight at 0.75A. A typical magnetic door strike (0.5A) plus a card reader (0.2A) equals 0.7A — you're at 93% of capacity with zero margin. Real-world surges or multiple simultaneous activations will exceed the limit. Measure your actual peak load and confirm you have 10–15% headroom before installation.
- Operating temperature ceiling of 49°C (120°F) is a hard limit, not a guideline. Sealed lead-acid battery life degrades sharply above 40°C. If your control cabinet is mounted in an unheated warehouse, uninsulated closet, or exposed to direct sun, plan for thermal management — ventilation holes, external cooling fan, or relocation to climate-controlled space.
- Battery replacement every 3–5 years is a maintenance task. Sealed lead-acid cells hold a charge for years, but float-charge systems in warm environments degrade faster. Budget for replacement and train your team on safe battery disposal — these are hazardous waste in most jurisdictions.
The AL62424C is the default choice for single-door access control retrofit projects and alarm panel backups where AC power is intermittently interrupted. If your deployment requires multiple simultaneous 24VDC loads or sustained high current draw, step up to a higher-capacity model in the Altronix power infrastructure lineup. For straightforward door strike and reader installations with predictable load profiles and acceptable backup windows (4–8 hours), this unit delivers reliability at a fair cost.
