Altronix OLS120D2 Dual-Output 12VDC/24VDC Power Supply with Battery Backup
The Altronix OLS120D2 is a board-form power supply engineered for security installations where 12VDC and 24VDC devices must run on independent, supervised power rails. It accepts 115/230VAC input (selectable at commissioning) and distributes up to 4A per output, making it suitable for small-to-medium access control clusters, auxiliary door strikes, gate operators, and low-power camera feeds that cannot share a single voltage rail. Built-in battery backup conditioning and AC fail/low battery supervision signals mean the OLS120D2 integrates directly into intrusion panels and access controllers without requiring external monitoring logic.
Key Features
- Dual independent outputs (12VDC and 24VDC): Mixed-voltage deployments avoid daisy-chaining single-output supplies or routing multiple wall-warts. Each rail carries its own 4A budget, so a 24VDC door strike pulling 2A won't starve a 12VDC reader on the other output.
- 4A per output: Supports up to four standard magnetic door strikes (typically 0.5–0.8A each at 24VDC) or eight 12VDC entry readers or badge encoders. Verify your device current draw against the cumulative load before commissioning.
- Selectable input (115VAC or 230VAC): Configurable at board level — avoids stocking two SKUs and simplifies global logistics. Set once during integration; no field reconfiguration needed.
- Integrated battery charging and backup: Accepts external 12V or 24V batteries (common SLA or lithium types) and manages charging automatically. On AC loss, the OLS120D2 switches to battery-supplied rails without a gap, keeping door strikes and readers live during power events.
- AC fail and low battery supervision signals: Discrete relay or contact closures alert the access panel or monitoring system to AC line loss or depleted reserve capacity. No need for separate monitoring relays — critical for systems that must log power events or trigger audible/visual alarms.
- Board-form enclosure: Mounts directly into larger cabinets, wall boxes, or vertically stacked enclosures. Compact footprint — approximately 5.5" wide × 3.5" tall — integrates into standard DIN rail frames alongside access control modules or terminal blocks without significant real estate impact.
Integration & Deployment Context
The OLS120D2 fits cleanly into access control systems where readers, strike plates, and mag-locks operate on different voltage standards. Typical setups include 24VDC for electrified locks and 12VDC for credential readers and auxiliary sensors. Its battery supervision is compatible with any legacy or modern panel that expects a normally-open or normally-closed contact for AC fail detection — no firmware updates or integration complexity required.
For security power supply applications, the OLS120D2 competes in the entry-to-mid-tier of dual-output solutions. It is not a heavy industrial UPS (no surge suppression, no harmonic filtering) and is not intended for continuous-duty power conditioning. Its strength lies in small-system affordability and straightforward installation without external relay logic.
Typical Load Scenarios
- Small office entry: One 24VDC strike (0.6A) + one 12VDC card reader (0.3A) + one 12VDC electric latch release (0.2A) = well within 4A per rail.
- Warehouse single access point: Two 24VDC mag-locks (1.6A total) + four 12VDC proximity readers (1.2A total) + spare capacity for future expansion.
- Multi-door gatehouse with backup: Configure with 12Ah SLA battery; on AC loss, strike and reader power sustains for 20–40 minutes depending on device duty cycle.
Because the OLS120D2 draws no external auxiliary power, installation is straightforward: run 115/230VAC mains to terminals, set the input voltage selector, wire the 12VDC and 24VDC outputs to loads and battery backup, and connect the AC fail/low battery contacts to your supervision circuit. No software, no commissioning code, no driver downloads.
Limitations & Considerations
- No surge suppression or transient filtering: If lightning strikes the AC mains or a load shorts out, the OLS120D2 will shut down to protect its internal regulators. Install an upstream surge protector or UPS for sites in high-strike zones or on unreliable utility lines.
- 4A per output is modest by industrial standards: If you're powering six door strikes at 24VDC, you'll exceed this supply. In that case, consider a higher-capacity power distribution system or cascade multiple OLS units on separate breakers.
- Board-form only — no standalone enclosure: The OLS120D2 must be mounted inside a cabinet or DIN rail frame. If you need a ready-to-install wall-mount unit with knockouts for cable entry, a rackmount chassis may be required.
Frequently Asked Questions
Q: Can I use the OLS120D2 with a 48VDC or 5VDC device?
A: No. The unit outputs only 12VDC and 24VDC. Do not attempt to daisy-chain or tap alternate voltages. For 48VDC PoE or 5VDC IoT devices, use a separate dedicated supply.
Q: What battery type does the OLS120D2 charge?
A: Standard 12V and 24V sealed lead-acid (SLA) batteries are supported. Lithium backup batteries may be compatible, but verify the manufacturer's charge termination voltage and peak current limits against the OLS120D2 charger circuit before deployment. Consult the OLS120D2 datasheet for exact charging specifications.
Q: How long will backup power last if AC fails?
A: Runtime depends on battery capacity (Ah) and load (A). A 12Ah SLA battery with a 2A load yields roughly 6 hours; a 4A load yields 3 hours. Calculate: Battery Ah ÷ Load A = Hours. Size your battery accordingly for your site's acceptable downtime.
Q: Does the OLS120D2 work with NVR or video management software?
A: The OLS120D2 is a power supply, not a networked device. It has no IP address or web interface. It supplies DC power only and reports AC/battery status via discrete relay contacts. Connect those contacts to a monitored input on your NVR's GPIO or alarm input card to log power events.
Q: Is there a warranty?
A: Yes. The OLS120D2 includes a Lifetime Limited Warranty covering defects in material and workmanship under normal use. Confirm coverage specifics with your supplier or Altronix documentation.
Ted PerryPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The Altronix OLS120D2 is a straightforward, no-nonsense entry point for mixed-voltage backup power in access control and small security installations. Its 4A per output spec is the critical constraint here — it's generous enough for a single-door entry or a small gatehouse, but underdimensioned for high-density multi-strike deployments. The built-in battery charger and AC fail supervision are the real value-adds; they eliminate external relay logic and integrate seamlessly into legacy access control panels that expect a simple contact closure for AC loss detection.
Technical Highlights:
- Dual independent 4A outputs: Eliminates voltage rail conflicts. A 24VDC strike and 12VDC reader can operate simultaneously without competing for headroom, which matters in older buildings where running separate conduit is expensive.
- Integrated battery charging: No external charger module needed. The OLS120D2 manages charge termination and float voltage internally — one less piece to source and one less point of failure in the cabinet.
- AC fail and low battery supervision: Discrete relay contacts provide early warning to the access panel, logging power events without requiring network integration or software polling.
Deployment Considerations:
- Load calculation is non-negotiable: Sum the continuous current draw of all 24VDC devices, all 12VDC devices separately. If either rail exceeds 4A, the OLS120D2 will shut down or enter current-limiting mode. Most integrators underestimate door strike duty cycles and get caught with an insufficient supply during final punch-list testing.
- No surge suppression: Install an upstream surge protector or battery-backed UPS on the AC mains input, especially in rural or lightning-prone areas. The OLS120D2 will survive a minor transient, but a direct strike or capacitive discharge fault will take it offline and leave your doors unlocked.
- Battery size determines real backup window: The 4A capacity is useless if your 12Ah battery dies in 3 hours. Factor in night-shift occupancy, UPS recharge time, and your site's tolerance for extended downtime. A 24Ah SLA costs less than a service call at 2 a.m.
The OLS120D2 is the right fit for single-door offices, small warehouses, and kiosk-style access points where one or two strikes and a handful of readers share a common cabinet. For multi-floor buildings or campuses with distributed doors, move up to a higher-capacity supply or cascade multiple OLS units with separate AC breakers. It's not a limitation — it's honesty about design scope.
