#20UPS Battery Thermal Runaway & BMS Audit
Multi-Asset / Multi-Point Equipment Schedule
Inspect multiple transformers, panels, rooms, motors, or RCDs in this module without overwriting previous assets. Each item receives a permanent QR Sticker UID preserved across annual audits.
Sticker UID: OC-BATT-CD48Standard Limits, Equations & Space Presets
NFPA 855 & IEEE 1188 Stationary Energy Storage thermal runaway diagnostics: cell-to-ambient temperature rise, float current runaway escalation, and cell ohmic trend.
Measured Inputs
Calculated / Evaluated Results
Thermal runaway screening combines cell-to-ambient delta T, float current trend and ohmic rise against baseline. Numeric triggers follow IEEE 1188 trending guidance and OEM data; NFPA 855 governs spacing, detection and suppression in the checklist.
Pending / Not tested — results stay neutral until valid measured values are entered.
- Pending
Cell Delta T vs Ambient
- degC
Not tested - enter the measured value. Acceptance: Delta T <= 5 degC; rising cell temperature together with rising float current is the classic runaway signature [IEEE 1188 §6 / OEM guidance]
- Pending
Cell-to-Cell Temperature Spread
- degC
Not tested - enter the measured value. Acceptance: Spread <= 3 degC across the string [Field convention]
- Pending
Float Voltage Deviation
- %
Not tested - enter the measured value. Acceptance: Within +/-2% of the temperature compensated float set point [IEEE 1188 §6.2]
- Pending
Internal Resistance Rise vs Baseline
- %
Not tested - <= 20% rise: acceptable. [IEEE 1188 §6.4]
- Pending
Float Current Rise vs Baseline
- %
Not tested - enter the measured value. Acceptance: A float current sustained more than about 50% above baseline at constant temperature indicates runaway onset [IEEE 1188 Annex / OEM guidance]
Verification Checklist (0 / 17)
1Battery Management System (BMS / cell-monitoring system) online with 100% of strings, blocks, and individual cell sensors reporting
2Cell negative-post temperature sensors cross-calibrated against calibrated infrared thermal camera (Delta T <= 5 degC over ambient) [IEEE 1188]
3Cell-to-cell temperature spread across each string verified <= 3.0 degC with no localised air-conditioning dead zones
4Temperature-compensated float charging (-3 mV/cell/degC for VRLA) enabled and verified functional on UPS rectifier
5Steady-state float charge current trend reviewed (> 50% rise at constant voltage/temp flags exothermic thermal runaway onset)
6Individual cell float voltages verified within +/-2% of nominal and <= 0.05 V string spread
7Internal ohmic resistance / conductance measured on every block; cells > +20% above baseline flagged, > +50% scheduled for immediate replacement [IEEE 1188 §6.4]
8Infrared thermography scan of all inter-cell busbars, tier cables, and DC breaker terminals completed under current flow
9VRLA pressure relief valves inspected for dry salt encrustation, electrolyte weeping, or container pillowing/swelling
10Li-ion BESS rack-level / module-level BMS over-voltage, under-voltage, over-current, and over-temperature contactor trip interlocks proven [UL 1973 / UL 9540A]
11Battery room HVAC redundancy (N+1 cooling) and dedicated hydrogen / off-gas extraction airflow rate verified [EN 50272-2 / NFPA 855]
12Hydrogen (H2) and thermal runaway off-gas (CO / VOC) gas detectors calibrated and interlocked to boost extraction fan at 1% LEL (25% of 4% LEL) and trip DC breaker at 2% LEL
13Very Early Warning Aspirating Smoke Detection (VESDA) and clean-agent / water-mist fire suppression operational in battery room [NFPA 855 §4.9]
14Minimum separation clearances between battery racks and fire-rated enclosure barriers maintained per NFPA 855
15Remote DC battery disconnect / shunt-trip pushbutton accessible outside battery room entrance door and clearly labelled
16BMS high-temperature, high-float-current, and impedance-drift critical alarms verified end-to-end with 24/7 NOC / BMS
17Defective cell replacement log, torque records, and hazardous waste disposal manifests updated
General Notes
Free plan: 5 of 5 inspections / calculations left this month.