calc.engineer / Solar & Power / UPS Runtime

UPS Runtime v1.0.0

Estimates UPS (Uninterruptible Power Supply) backup runtime from battery specifications and connected load. Takes VA rating, watt rating, load in watts, and battery configuration (count, voltage, amp-hours) to compute effective stored energy after efficiency losses and runtime in minutes and hours. Detects overload conditions when load exceeds the UPS watt rating. Calculates power factor from VA/W ratings. Ideal for server rack planning, homelab power budgeting, network closet UPS selection, and graceful shutdown timer configuration.

← from battery_life← from solar_sizingfeeds battery_life →
UPS VA (volt-ampere) rating
UPS real power (watt) rating
Connected load in watts
Number of batteries in the UPS
Voltage per battery (V)
Capacity per battery in amp-hours (Ah)
Inverter/conversion efficiency (0-1), default 0.9
Fill in the inputs and Compute to see the structured result.

From an agent (MCP) or the API

curl -X POST https://calc.engineer/api/ups_runtime \
  -H "Content-Type: application/json" \
  -d '{"va_rating": …, "watt_rating": …, "load_watts": …}'

MCP: connect to https://calc.engineer/mcp and call ups_runtime.

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