Altronix's ReServ24B pairs dual 24VDC inputs with rapid battery charging
Altronix's ReServ24B supports two 24VDC power supplies and switches the load to the other input without delay if one drops. When power returns, it uses excess power to rapidly recharge SLA, gel or LiFePO4 backup batteries. It connects to the LINQ2 module for remote monitoring, control and reporting.
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Key facts, context, and what it means.
Key takeaways
When both 24V inputs are live, the ReServ24B feeds the load from whichever supply runs at the higher voltage, so the voltage setting decides which unit acts as primary.
A failover nobody sees is still a countdown: below 20V the battery-fed output shuts off and needs DC input power to restart.
Three supervision relays plus LINQ2 data on input status, battery status, output voltage and output current give a site a way to spot a failover well before the cutoff.
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SecurityInfoWatch's Aug. 12, 2026 product listing for the ReServ24B ran under the heading "GSX Booth 2833." Ronnie Pennington, Director of Sales for the Americas at Altronix, said in the launch announcement that integrators will find the ReServ24B easy to deploy. He added that the unit gives facility managers and end users confidence that access control and security systems will stay online and recover quickly.
For the integrator wiring the panel, and the security director who has to explain a dead door, the useful questions concern the edges. Which supply carries the load when both are healthy? What happens when the battery runs low? And how does anyone find out the site has failed over? Altronix's own product page answers most of that.
How the board picks its power
The press language talks about a primary and a secondary input. The redundancy logic on Altronix's spec page is more specific. When both inputs are present, the one with the higher voltage powers the output and the charging circuit. If that input is disconnected or sags, the other is routed to the output and the charger automatically. Both inputs accept 23 to 28VDC.
That suggests the "primary" supply is set by voltage, not by which terminal it's wired to. An installer who wants a particular supply to carry the load day to day would set that supply's output higher. That's a small commissioning detail, and it's easy to miss when two supplies are set to the same nominal 24V.
The battery side handles 24V LiFePO4, sealed lead acid or gel batteries, which are sold separately. Altronix lists the failover on loss of AC as instantaneous, and SecurityInfoWatch's product listing describes the transfer as happening without delay. According to Locksmith Ledger, the board uses excess available power to rapidly recharge the backup batteries, extending backup. For operators, that could mean a battery that refills faster after one outage is ready sooner for the next.
Per Altronix's spec page: if the battery discharges below 20V, the output is disabled, and one or both DC inputs must return to restart it. If both DC inputs are low or missing and only the battery is connected, the unit will start up from the battery.
Those two rules work together. A long outage that drains the battery ends with the output switched off, and the board won't bring connected devices back until supply power returns. A site where supply power is switched rather than constant, which is the use case Altronix names first, can still bring the board up from a charged battery alone.
The ratings an installer designs around
ReServ24B on the spec sheet
Altronix
Each input, the output and the battery circuit carry a 15A/32V fuse, and output voltage is listed at 22 to 24VDC. The board gives off about 34.1 BTU per hour, which matters mainly in an enclosure that is already full of warm power supplies. Relative humidity is rated at 85%, plus or minus 5%.
There is a catch in the word "rapid." Altronix describes charging as using the excess power left after the connected devices are fed. A supply already running close to its rating could have little spare current, so a 6A charge setting would matter less than the headroom in the supply behind it. The board's charging speed depends partly on how generously the rest of the power design is sized.
Who finds out the site failed over
Locally, the board reports through LEDs: green when the power supplies are feeding the load, red when the battery is, and blue for operation, components and fuses. It also has three normally closed relays rated 1A at 28V, one each for Input 1, Input 2 and battery status.
The network side runs through Altronix's LINQ interface and the LINQ2 module, which the company says allows remote monitoring, control and reporting. The product page lists what LINQ2 can see: DC input status, battery status, output voltage and output current. SecurityInfoWatch's listing frames this as visibility into power status and system diagnostics. Output current is the useful one for planning, because it shows how much of the 10A ceiling the connected devices actually draw.
That telemetry matters because a smooth failover is, by design, easy to miss. Doors keep working, cameras stay up and nobody calls. A failover nobody sees is still a countdown: the battery carries the load until it sags below 20V, then the output shuts off until DC power comes back.
Before the board goes in, decide who receives the battery-status relay and the LINQ2 alerts, and what they do when one fires. The board's value depends on someone seeing the switch to battery while the battery still has charge.
Which sites it suits
Altronix says the ReServ24B can be added to new or existing security and access control systems, and positions it for two jobs: sites where constant power isn't available because power is switched, and sites that need faster battery charging. The product page links to Altronix's lifetime warranty and to a distributor locator.
The ratings mark the boundary. This is a 24VDC device with a 10A output, so a system that runs at another voltage, or a load bigger than one board's ceiling, falls outside what a single unit covers. For a 24V access control panel already in place, though, adding a second supply and a monitored battery path becomes a matter of fitting a 3-by-5.5-inch board and selecting a charging current.
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