CyberPower ST900U
A standby UPS for a mid-range desktop PC when you do not need AVR or an LCD.
Amazon $119.95$119.95
The CyberPower ST900U and the CyberPower SL700U are evenly matched, rated 2.9 and 2.8. The CyberPower ST900U leads on output. The CyberPower SL700U costs $30 less ($89.95 vs $119.95).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
$89.95
Which should you buy?
- Choose the CyberPower ST900U for output (500 W rated output vs 370 W rated output).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every desktop (under 1,000 VA) UPS battery backup; a clear win is highlighted. How we rank explains each one.
| Factor weight | CyberPower ST900U | CyberPower SL700U |
|---|---|---|
| Overall rating | 2.9/5 | 2.8/5 |
| Value 25% | 77 $23.99 per 100 W ($119.95, 500 W) | 77 $24.31 per 100 W ($89.95, 370 W) |
| Output 15% | 16 500 W rated output | 8 370 W rated output |
| Topology and waveform 20% | 0 standby, simulated sine wave | 0 standby, simulated sine wave |
| Runtime 10% | 50 runtime at 100 W not published (neutral score used) | 50 runtime at 100 W not published (neutral score used) |
| Features 15% | 35 USB charging, software or network management | 35 USB charging, software or network management |
| Warranty 15% | 47 3-year warranty, $125,000 equipment guarantee | 44 3-year warranty, $100,000 equipment guarantee |
Specifications
| CyberPower ST900U | CyberPower SL700U | |
|---|---|---|
| Power | ||
| Rated apparent power | 900 VA | 700 VA |
| Rated real power | 500 W | 370 W |
| Topology | Standby | Standby |
| Battery waveform | Simulated sine | Simulated sine |
| Automatic voltage regulation | No | No |
| Outlets and features | ||
| Outlets | 12 (6 on battery) | 8 (5 on battery) |
| Format | Desktop | Desktop |
| Display | LED indicators | LED indicators |
| USB charging ports | Yes | Yes |
| Data port, software or network option | Yes | Yes |
| Warranty | ||
| Warranty | 3 years | 3 years |
| Connected-equipment guarantee | $125,000 | $100,000 |