Model capacity fade using cycle and calendar aging. Adjust chemistry, temperature, depth, and charging speed. See remaining capacity instantly, then export your results today.
This estimator combines cycle aging and calendar aging. It uses equivalent full cycles (EFC) and a square-root time fade term.
| Scenario | Chemistry | Temp (C) | DoD (%) | Cycles/day | Storage SoC (%) | Months | Expected SoH trend |
|---|---|---|---|---|---|---|---|
| Warehouse backup | LFP | 22 | 30 | 0.1 | 50 | 24 | Slow fade, calendar-dominant |
| E-bike commuter | NMC | 30 | 75 | 1.0 | 70 | 18 | Moderate fade, cycle-dominant |
| High-speed charging | NCA | 35 | 80 | 1.2 | 80 | 12 | Faster fade, higher stress |
| Heat-exposed device | LCO | 45 | 60 | 0.8 | 90 | 10 | Calendar accelerates strongly |
| Lead-acid UPS | Pb | 28 | 50 | 0.2 | 100 | 36 | Calendar plus float stress |
EFC converts partial cycling into a comparable throughput measure. A device running 1.0 cycle/day at 70% depth equals about 0.70 EFC/day. Over 12 months (about 365 days) that is roughly 256 EFC. Compare this with rated cycle life that is usually quoted near 80% SoH at a reference depth. If your average depth is lower, the same number of trips can produce less total throughput. For fleet logs, compute depth from discharged amp-hours divided by nominal capacity daily.
Heat is one of the strongest accelerators for both cycling and storage fade. With Q10 set to 2.0, moving from 25C to 35C doubles the rate; 45C is about 4×. At 32C the multiplier is roughly 2^0.7 ≈ 1.62. Cooling from 35C to 28C cuts the multiplier to about 2^0.3 ≈ 1.23, which often matters more than small changes in usage.
Higher depth increases mechanical and chemical strain. The DoD exponent controls sensitivity: with alpha 0.35, changing from 50% to 90% DoD shifts the DoD factor from (50/80)^0.35 ≈ 0.85 to (90/80)^0.35 ≈ 1.04. C-rate affects polarization and heat; above 0.5C the model applies a linear penalty, so 1.5C can add noticeable stress even if total EFC stays constant.
Calendar loss uses a square-root time trend, reflecting faster early loss that slows later. Two years does not double one year; √2 is only 1.41×. Storage SoC matters: holding 90% SoC typically ages faster than 50–60% SoC. For seasonal equipment, lowering storage SoC and temperature can reduce fade while keeping the same duty cycle during active months.
SoH is remaining usable capacity relative to nominal capacity. Many designs treat 80% SoH as end of first life, while performance-critical systems may choose 85% or 90% to protect range and power. The projected date assumes future conditions match your inputs and uses a search to find when SoH crosses your threshold. The risk index blends temperature, storage SoC, C-rate, DoD, fast-charge share, and current SoH into a 0–100 scale for scenario comparison.
SoH estimates remaining capacity versus nominal capacity. SoC is the current charge level at a moment in time. A battery can be 80% SoH and still reach 100% SoC after charging.
EFC normalizes partial cycling. Two 50% cycles move about the same charge as one 100% cycle, so EFC better represents throughput stress when usage depth changes from day to day.
Use logged charge throughput. Sum discharged amp-hours (or watt-hours) per day and divide by nominal capacity (or energy). That yields an effective cycles/day even when trips, loads, and depths vary.
Not always, but higher charge power can raise temperature and accelerate side reactions. If fast charging is well managed with cooling and conservative voltage limits, the penalty can be smaller than in hot, high-SoC charging.
Common engineering thresholds are 80% SoH for general use and 85–90% when range, power, or safety margins are tight. Choose a threshold that matches your performance requirements and maintenance plan.
Yes. Set chemistry close to your cell, then tune the advanced assumptions so the estimator matches vendor curves at reference temperature, depth, and cycles. Keep changes modest and validate with at least two operating points.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.