Immersion Cooled Degradation Curve
EticaAG immersion cooling keeps cell temperatures uniform, slows degradation, extends useful life, and improves confidence in long-term BESS returns.
Why Degradation Matters
Battery degradation is more than a chemistry issue, it’s a thermal management issue. When cell temperatures drift apart, batteries age unevenly, usable capacity falls faster, and financial models break down sooner than expected. EticaAG’s immersion cooling is built to maintain uniform cell temperatures, preserve State of Health, and support stronger lifetime performance.
Projected State of Health (SOH) Over Time
Under the same operating assumptions, immersion cooling preserves more usable capacity across the life of the system than standard liquid cold plate cooling.
| Year | Standard 0.25C | Immersion 0.25C |
| 0 | 100.00% | 100.00% |
| 1 | 94.43% | 94.83% |
| 2 | 91.49% | 92.29% |
| 3 | 89.46% | 90.66% |
| 4 | 87.57% | 89.17% |
| 5 | 86.35% | 88.35% |
| 6 | 84.55% | 86.95% |
| 7 | 83.42% | 86.22% |
| 8 | 81.85% | 85.05% |
| 9 | 80.67% | 84.27% |
| 10 | 78.96% | 82.96% |
| 11 | 77.85% | 82.25% |
| 12 | 76.35% | 81.15% |
| 13 | 75.24% | 80.44% |
| 14 | 74.14% | 79.74% |
| 15 | 72.66% | 78.66% |
| 16 | 71.56% | 77.96% |
| 17 | 70.47% | 77.27% |
| 18 | 69.37% | 76.57% |
| 19 | 67.92% | 75.52% |
| 20 | 66.83% | 74.83% |
Higher SOH Retention
At Year 10, immersion retains 83% SOH vs. 77% with standard cooling, preserving more usable energy over project life.
Longer Useful Life
Immersion keeps the system above 80% SOH at Year 13, while standard cooling drops below 80% by Year 9, extending useful life by about 4 years.
Stronger End-of-Life Value
At Year 20, immersion retains 75% SOH vs. 67% with standard cooling, preserving more usable capacity at end of life.
Degradation Curve Assumptions
- 1 cycle per day
- Cycling at 0.25C and 100% DOD
- Operating ambient temperatures within -30°C to 45°C (-22°F to 113°F)
- Indicative degradation curves from simulation are provided for reference only
Why Battery Degradation Accelerates in Conventional BESS
Battery life depends on temperature uniformity. When cells run at different temperatures, they age at different rates, reducing usable capacity, shortening system life, and weaken long-term ROI. Conventional liquid cold plate systems remove heat, but do not cool every cell evenly.
Hot Spots
Localized heat accelerates uneven aging, shortens battery life, and reduces overall system efficiency over time.
Thermal Gradients
Uneven cell temperatures create mismatch across the pack, driving earlier fade and less predictable long-term performance.
Indirect Cooling
Cold plates remove heat, but surface-contact cooling makes uniform cell-level thermal management harder to maintain.
Earlier Fade
When degradation starts sooner, usable capacity drops earlier and project economics come under more pressure.
Why Immersion Cooling Slows Battery Degradation
Immersion cooling slows degradation by controlling temperature at the cell level. Each cell is surrounded by dielectric fluid that removes heat directly, reduces hot spots, and keeps the battery operating in a tighter thermal range over time.
Direct Cooling
Immersion removes heat directly from all cell surfaces, avoiding the thermal resistance and uneven contact found in cold plate systems.
Thermal Uniformity
Immersion reduced cell temperature variation by about 50%, improving consistency across the battery array and slowing uneven aging.
Hot Spot Prevention
By lowering Tmax and ΔT, immersion limits localized overheating that drives faster fade, mismatch, and usable capacity loss.
Longer Battery Life
EticaAG testing showed immersion extended battery life by 20%, with higher retained ampere-hour capacity than cold plate cooling.
See How Immersion Changes the Degradation Curve
Talk with EticaAG about degradation modeling, usable life, augmentation timing, and how immersion cooling can improve long-term BESS returns.