A battery energy storage system uses a 500 kWh lithium-iron-phosphate (LFP) pack at a 0.5C discharge rate delivering 250 kW for 2 hours. Cell skin temperature can reach 42°C at peak discharge. Calculate thermal load, confirm air-cooling is adequate (ΔT ≤ 10°C rise at 1000 CFM), and check if 0.5C falls within the manufacturer C-rate envelope of 1.0C max continuous.
| Pack capacity | 500 kWh (LFP chemistry) |
| Nominal voltage | 1536 V (480s × 3.2 V) |
| Discharge rate | 0.5 C (250 kW output) |
| Discharge duration | 2 h |
| Cell internal resistance | 0.3 mΩ per cell |
| Heat transfer coefficient | h = 8 W/m²K (air-cool) |
| Cooling air flow | 1000 CFM (472 L/s) |
| Ambient temperature | θ_amb = 25 °C |
| Check | Status | Util. | Value |
|---|---|---|---|
| C-rate check | PASS |
|
0.5C ≤ 1.0C max — within manufacturer envelope |
| Cell current at 0.5C | PASS |
|
I = 163 A (pack), I_cell = 163 A per string |
| Thermal generation (I²R) | PASS |
|
Q_gen = 15.9 kW (all losses) |
| Cooling capacity — air | PASS |
|
Q_cool = 18.1 kW at ΔT = 8°C rise |
| Cell skin temperature | PASS |
|
θ_skin = 33°C ≤ 45°C alarm threshold |
| ΔT air supply vs return | PASS |
|
ΔT = 8.0 °C ≤ 10 °C max — air-cool OK |
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