UPS Capacity / Battery Backup
Select UPS capacity, battery string voltage, and battery capacity from critical load, power factor, and backup time; back-calculate actual backup time.
Key points
UPS Capacity / Battery Backup: Select UPS capacity, battery string voltage, and battery capacity from critical load, power factor, and backup time; back-calculate actual backup time. Formula: S_UPS ≥ P/(cosφ·loading) | C = P·t/(η·DoD·U_bat). Enter parameters on the DD-CAT IDE online tool page to get results instantly, with a calculation-model diagram that updates with the inputs. Select UPS capacity in VA and match load PF to UPS output PF; inductive / rectifier loads also need crest-factor and startup-surge checks. Battery capacity is estimated by energy balance; actual performance depends on discharge rate, temperature, aging, and end voltage. Use manufacturer curves for critical sites.
Inputs
S_UPS ≥ P/(cosφ·loading) | C = P·t/(η·DoD·U_bat)Calculation model (updates with parameters)
| Suggested UPS capacity | 15 kVA | P/(cosφ)×K = 13.89 kVA |
| Required battery energy | 6.944 kWh | P·t/(η·DoD), by直流侧估算 |
| Required battery capacity | 36.2 Ah | Energy / Battery stringVoltage |
| Recommended battery capacity | 40 Ah | 按常用Battery capacity档向上取整 |
| Actual backup time | 33.2 min | C·U·η·DoD/P |
| Battery string configuration | 16 × 12V | nominal 192 V Battery string |
| Battery discharge current | 57.87 A | 额定load时的直流current，用于选熔断器 / 电缆 |
Engineering notes
- Select UPS capacity in VA and match load PF to UPS output PF; inductive / rectifier loads also need crest-factor and startup-surge checks.
- Battery capacity is estimated by energy balance; actual performance depends on discharge rate, temperature, aging, and end voltage. Use manufacturer curves for critical sites.
- Longer backup means a larger battery, and the charger and battery-room ventilation must be checked too; periodic discharge tests are needed to confirm actual backup.
FAQ
- What is UPS Capacity / Battery Backup for?
- Select UPS capacity, battery string voltage, and battery capacity from critical load, power factor, and backup time; back-calculate actual backup time.
- What is the formula for UPS Capacity / Battery Backup?
- Core formula: S_UPS ≥ P/(cosφ·loading) | C = P·t/(η·DoD·U_bat). The tool returns results instantly using this formula and the selected parameters.
- What engineering notes should I keep in mind when using UPS Capacity / Battery Backup?
- Select UPS capacity in VA and match load PF to UPS output PF; inductive / rectifier loads also need crest-factor and startup-surge checks. Battery capacity is estimated by energy balance; actual performance depends on discharge rate, temperature, aging, and end voltage. Use manufacturer curves for critical sites. Longer backup means a larger battery, and the charger and battery-room ventilation must be checked too; periodic discharge tests are needed to confirm actual backup.