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General Overview

The Onyx SXi 21" Lithium-Ion Burnisher delivers powerful, eco-friendly performance in a compact, easy-to-use design. Its patented floating shroud and advanced dust collection system capture fine polymer dust during operation, eliminating the need for dust mopping. The integrated micro-filter vacuum bag traps particles as small as 0.5 microns, improving indoor air quality while meeting strict Green Seal GS-42 and LEED standards.

Powered by lithium iron phosphate battery technology, this model runs quietly and efficiently, avoiding the noise and emissions of propane alternatives. With up to 2 hours of runtime per charge, the SXi combines convenience, high productivity, and professional results, making it a reliable choice for schools, hospitals, and commercial facilities.


Included in Your Package

  • Onyx 21" Lithium-Ion Powered Floor Burnisher

  • Single 60 AH Lithium Iron Phosphate Battery

  • Floating Dust Containment Shroud

  • Integrated Micro-Filter Vacuum Bag

  • Onboard Smart Battery Charger


Key Features

  • Lithium-Ion Battery Powered – Long runtime, fast recharge, no cords, no fuel.
  • Zero Emissions & Ultra-Quiet – Safe for schools, hospitals, retail, and high-traffic indoor spaces.
  • Propane-Grade Performance – All the gloss, none of the fumes.
  • Fewer Passes, Higher Gloss – Engineered for maximum shine with reduced labor and pad use.
  • Three Head Size Options – Easy head size change from 21", 24" or 27". Can we ordered in any of these three head sizes. 
  • Configuration Versatility – Variable speed range (600 - 1,800 RPM), onboard 10-gallon water tank for stripping/polishing use, wide range of pad/brush down-force adjustments.
  • Advanced Dust Control – Cleaner air, healthier workspace, and superior finish quality.

Specifications

  • Working Width: 21"

  • Motor Power: 5 HP (3.75 kW)

  • System Voltage: 72 V

  • Battery Capacity: 60 AH / 4.32 kWh (single battery)

  • Battery Life: 2,500 cycles

  • Runtime: Up to 2 hours per charge

  • Charge Time: 4.8 hours

  • Coverage Rate: Up to 34,000 sq. ft. per hour

  • Pad Speed: 1,050–1,800 RPM (variable)

  • Sound Level: <63 dBA

  • Pad Pressure: 20–120 lbs (variable)

  • Dimensions: 29"W × 64"L × 42"H

  • Weight: 245 lbs (with battery)

  • Water/Solution Tank: 10 gallons (disconnected in burnisher mode)


Product Documents 

SXi Data Sheet

Product specification and additional features.  

Operator Manual

Full operation, maintenance, and safety guide.

Illustrated Parts List

Complete parts list and ordering information.

Wiring Diagram

Complete electrical wiring diagram for troubleshooting.

Product Videos

Manufacturer Warranty

All Onyx products purchased through Centra Supply carry Onyx’s standard manufacturer warranty. Onyx units carry a 3/3/3/3 warranty — 3 years on parts, labor, motor, and the rotationally-molded body. Coverage varies by product line — contact us for the exact terms on this model.

To Claim: Email support@centrasupply.com with your order number, product model, and a description of the issue. Photos or video of the defect may be requested. Most claims are acknowledged the same business day.

Centra Supply is an authorized Onyx dealer — your warranty is fully valid and manufacturer-backed.