Inverters.
Old technology, at twice the cost.
A central lighting inverter is centralized like Sage. That's where the similarity ends. On the same building, Sage installs for 49% less on day one and runs the decade at 7× lower upkeep. No crossover, ever.
The inverter got one thing right.
Centralize the power source.
Credit where due: a central lighting inverter consolidates emergency power in one serviceable location, it can back any load type, its automatic test and reporting package is standard equipment, and every electrical engineer in the country has specified one. Those are real virtues. They are the same virtues Sage is built on.
Everything around those virtues is legacy architecture. An inverter must carry every connected fixture at 100% of its normal wattage, so it is sized far beyond what egress actually needs. It double-converts power: AC to DC to AC, and then every LED driver converts it back to DC again. It feeds fixtures through rigid conduit at line voltage. And on every dimmed or switched circuit, code demands a UL 924 bypass device to force the lights up when the power fails. All of that is purchased, installed, and maintained for capability the building never uses.
The inverter's install ledger, itemized.
Worked on our reference design: a 42,000 sq ft school with 87 emergency fixtures and 24 exit signs. Every line is market pricing a specifier can check.
Why the ALCRs disappear.
An inverter feeds fixtures through their normal controls. When a circuit is dimmed to 10% and the power fails, code requires those lights at full emergency output, so every controlled circuit needs a UL 924 device to bypass the dimming signal. On this design, that's 28 devices bought, wired, and maintained.
The Sage Relay wires downstream of the LED driver. In an emergency it switches the LED load directly onto the central battery's 24 VDC. The dimming signal never reaches the emergency path: there is nothing to bypass, so there is no bypass device. The entire ALCR line item, hardware and labor, vanishes from the project.
This isn't a workaround; it's the architecture doing the code's job by construction. Emergency power that never passes through normal controls cannot be dimmed off by them. The same principle governs Europe's EN 50171 central-battery systems, the dominant egress architecture there for decades.
Proprietary batteries are where inverters get expensive.
The inverter's battery cabinet holds 16 proprietary batteries at $250 each, replaced on a five-year cycle with electrician labor at $95/hr. Two replacement cycles land inside the decade: $4,760 per event, $9,520 total.
Sage's cabinet uses 4 commodity 12 V batteries (~$150 each) on the same cycle, a 2-hour change-out your own facilities staff performs at $36/hr. Low-voltage work needs no electrician. That is the whole 7× difference.
Further ahead every year.
Battery packs at least win the day-one line before losing the decade. The inverter never leads at all: behind on day one, and the gap widens every year after. There is no crossover point.
Two centralized systems. One modern architecture.
| Central lighting inverter | Sage Central Battery | |
|---|---|---|
| Sizing basis | ⚠ 100% of connected fixture wattage — the inverter carries every fixture at full output | ✓ Egress load only — the relay switches each fixture to its emergency level |
| Power path | ⚠ AC → DC → AC double conversion, then back to DC inside every LED driver | ✓ Native 24 VDC from the battery to the fixture — one conversion, once |
| UL 924 dimming bypass (ALCR) | ⚠ One per controlled circuit — 28 devices at $150 each, plus installation | ✓ Zero — the relay wires downstream of the driver, so there is no dimming signal to bypass |
| Wiring method | ⚠ Rigid conduit, ~2,600 ft at 5 hr/100 ft — 130 labor hours | ✓ Class-2 low-voltage cable, ~2,300 ft at 2 hr/100 ft — 46 labor hours |
| Batteries over the decade | ⚠ 16 proprietary batteries at $250 each, replaced on a 5-year cycle with electrician labor | ✓ 4 commodity 12 V batteries (~$150 each), a 2-hour in-house change-out |
| Automatic testing + reporting | ✓ Standard equipment on modern inverters | ✓ Standard with the system — Sage Live™ |
| Day-one installed cost | $$$ $55,327 on the reference design | $ 49% lower on the same building |
| Ten-year upkeep | $$$ $9,520 in battery-set replacements | $ 7× lower |
Worked figures, not marketing math.
Every number on this page comes from one worked reference design: a 42,000 sq ft school with 87 emergency fixtures, 24 exit signs, and 28 controlled circuits, priced at defensible mid-market rates: contractor labor $95/hr, in-house maintenance $36/hr, UL 924 devices $150 each. Hardware at wholesale/trade pricing on both columns; labor at prevailing market rates.
Challenge any unit price. We'll gladly re-run the model on your numbers. The architecture wins on any honest inputs.
Same centralization. Half the day-one cost.
If a project is already leaning central, and central is the right instinct, Sage delivers everything the inverter promised, at a fraction of the install and a fraction of the upkeep, with the compliance audit trail built in.