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APC 850VA/510W Pro UPS Battery Backup for Office Electronics, AVR, BX850M
APC

APC 850VA/510W Pro UPS Battery Backup for Office Electronics, AVR, BX850M

Bottom line: The APC 850VA/510W Pro UPS Battery Backup for Office Electronics ($161.99 on Amazon as of 2026-10-09): Over 29 minutes of runtime at a 100W load for routers, modems, NAS, and a PC; main trade-off: 510W output ceiling limits runtime for a high-wattage gaming PC under heavy load.

$161.99

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By , Founder & Editor-in-Chief · Listing data updated

Mike Perry — Hardware researcher since 2014. For retro PC hardware and period-correct parts, synthesises manufacturer documentation, community compatibility lists and marketplace listings rather than first-hand lab testing. Core beat: GPU performance across gaming, rendering, and local-LLM inference.

*Price sourced from Amazon.com. Last updated 2026-10-09. Price and availability subject to change.

Pros & Cons

Pros

  • ✓ Over 29 minutes of runtime at a 100W load for routers, modems, NAS, and a PC
  • ✓ 8 outlets: 4 battery backup plus 4 surge-only, with coax and Ethernet surge protection
  • ✓ AVR corrects brownouts from 88V and +/-13% surges without draining the battery
  • ✓ Active PFC compatible, so it suits gaming PCs with modern power supplies
  • ✓ LCD shows charge level, load, estimated runtime, and power conditions

Cons

  • ✗ 510W output ceiling limits runtime for a high-wattage gaming PC under heavy load
  • ✗ Only 4 of the 8 outlets get battery backup; the other 4 are surge-only
  • ✗ Replacement battery (RBC17) is sold separately
  • ✗ Built for short outages: plan to save work and shut down, not ride out long blackouts

Manufacturer description

The APC BX850M Back-UPS Pro is an 850VA/510W UPS battery backup built to keep your computer, network gear, and home office electronics running through blackouts, brownouts, and power surges. APC rates it for over 29 minutes of backup runtime at a 100W load, which is enough time to keep a Wi-Fi router, modem, NAS, or desktop PC online through a short outage, or to save your work and shut down cleanly. You get eight outlets: four battery backup outlets for essential devices and four surge-only outlets for peripherals. Built-in coaxial and Ethernet surge protection also covers your cable and…

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SpecPicks Verdict

SpecPicks scored APC 850VA/510W Pro UPS Battery Backup for Office Electronics using a rating × review-volume × price-fit model applied to published specs and reviews across the power protection category. APC's power protection lineup sits within the broader category mid-tier; price and specs are the deciding factors over brand loyalty here. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.

Common buyer scenarios for power protection of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.

Frequently Asked Questions

How long will the APC BX850M run on battery?

APC rates it for over 29 minutes at a 100W load. Heavier loads shorten runtime, so a desktop PC plus a monitor will run for less time than a router and modem alone. The LCD shows the estimated runtime for your actual load.

Will the APC BX850M work with a gaming PC?

Yes, as long as the load stays within its limits. It is Active PFC compatible, which modern gaming power supplies require. Its maximum output is 510W, so add up what your PC and monitor actually draw before you plug them into the battery outlets.

How many devices can I plug into the BX850M?

It has 8 outlets: 4 battery backup outlets that stay powered during an outage and 4 surge-only outlets for peripherals that don't need backup power. It also provides coaxial and Ethernet surge protection.

Can I replace the battery in the APC BX850M?

Yes. The battery is user-replaceable, and the replacement model is the APC RBC17, sold separately. Check the product listing or APC's documentation for current battery pricing and availability.

What warranty comes with the APC BX850M?

APC covers the BX850M with a 3-year warranty and Equipment Protection for connected devices. See APC's policy documents for the full terms and claim requirements.

Key Features

  • 850VA / 510W RELIABLE BACKUP POWER: Delivers short-term battery power to keep essential devices powered during blackouts, surges, and unexpected power interruptions
  • STAY CONNECTED WHEN IT MATTERS MOST: Provides over 29 minutes of backup runtime at a 100W load—keeping computers, TVs, DVRs, Wi-Fi routers, modems, external drives, NAS systems, and smart home devices powered during outages
  • EIGHT PROTECTED OUTLETS: Power your entire setup with 4 battery backup outlets for essential devices, plus 4 surge-only outlets for peripherals-plus built-in coaxial and Ethernet surge protection for added peace of mind
  • AUTOMATIC VOLTAGE REGULATION (AVR): Corrects low voltage brownouts (88V+) and surges (+/-13%) without draining battery-boosts or trims to stable 120V. Extends runtime for blackouts; Active PFC compatible for gaming PCs
  • REPLACEABLE BATTERY & ENERGY STAR UPS: User-replaceable battery (RBC17, sold separately) for zero-downtime swaps. ENERGY STAR certified for 92%+ efficiency, cutting energy costs vs standard UPS units
  • ENHANCED PROTECTION FOR CONNECTED ELECTRONICS: Supported by a 3-Year Warranty and $75,000 Equipment Protection, offering enhanced coverage for connected devices and added assurance against power-related damage

Full Specifications

BrandAPC
ColorBlack
Runtime6 minutes
Voltage120 volts
Wattage510 watts
Amperage16
Unit Count1 Count
Form FactorTower
ConnectivityWiFi
Model NumberBX850M
Input Voltage120 volts_of_alternating_current
Maximum Power510 watts
Built-In MediaUPS^User Manual^USB Cable^Coaxial Cable
Connector TypeNEMA
Item Type Namebattery backup UPS
Output Current16 A
Output Voltage120 volts_of_alternating_current
Output Wattage510 watts
Item Dimensions12.2 x 3.58 x 7.48 inches
Mfr Part NumberBX850M

Ready to buy?

APC 850VA/510W Pro UPS Battery Backup for Office Electronics, AVR, BX850M is listed on Amazon. Price, availability, shipping and returns are set by Amazon and its sellers — check the listing for current terms. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.

Buy on Amazon — $161.99

*Price sourced from Amazon.com. Last updated 2026-10-09. Price and availability subject to change.

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APC 850VA/510W Pro UPS Battery Backup for Office Electronics, AVR, BX850M
$161.99
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