UPS & Battery Backup: Which One Do You Need?

A UPS (uninterruptible power supply) keeps your computer, modem or NAS running through blackouts and brownouts, and gives you time to save your work and shut down safely. It also protects equipment from the power spikes and dips that shorten its life. Here is how to pick the right size, and the models we recommend.

How to size a UPS in two minutes

  • Add up the watts of what you will plug in. A modem and router use about 20–30W, a desktop PC 150–400W, a monitor 20–40W, a small NAS 30–60W.
  • Pick a UPS rated at least 30% above that total, in watts (not just VA). This leaves headroom and gives longer runtime.
  • More headroom means more minutes. A UPS running at half load lasts far longer than one running flat out.

Line-interactive vs standby

Line-interactive UPS units include AVR (automatic voltage regulation). They correct brownouts and surges without switching to battery, which saves battery life. They are the best choice for PCs, NAS and small servers. Standby / power-saving models are simpler and cheaper, and ideal for a modem, router or single desktop.

Home and small desk: modem, router, one PC

APC Back-UPS 750VA

APC Back-UPS 750VA

410W line-interactive, 3 AUS outlets

$208.99

APC Back-UPS 550VA Desktop

APC Back-UPS 550VA Desktop

330W, 8 AUS outlets, user-replaceable battery

$241.99

APC Back-UPS 950VA

APC Back-UPS 950VA

520W line-interactive, 4 AUS outlets

$252.99

Home office and NAS: PC, monitors, network and storage

APC Back-UPS 1200VA

APC Back-UPS 1200VA

650W line-interactive, 4 AUS outlets

$307.99

APC Back-UPS 1600VA

APC Back-UPS 1600VA

900W line-interactive, 4 AUS outlets

$395.99

APC Back-UPS Pro 900VA

APC Back-UPS Pro 900VA

540W, LCD, AVR, 6 IEC outlets

$647.99

Small business: servers, network racks, point of sale

PowerShield Defender 2000VA

PowerShield Defender 2000VA

1200W, AVR, LCD, 6 AUS sockets

$601.99

APC Easy UPS 1000VA

APC Easy UPS 1000VA

700W, 6 IEC outlets, network card slot

$625.99

APC Smart-UPS 750VA

APC Smart-UPS 750VA

500W, SmartConnect, LCD, 6 IEC outlets

$999.99

Quick tips

  • Plug the UPS straight into the wall, not into a power board.
  • IEC outlets need IEC power cables. AUS outlets take normal Australian plugs.
  • Batteries typically last 3–5 years. Models with user-replaceable batteries are cheaper to keep running.

Browse every model in Power & UPS, or send us a message with what you want to protect and we will help you choose.