Track capacity fade and translate it into money. Model cycling, calendar aging, and energy value. Get clear payback signals for smarter battery decisions now.
| Scenario | Cost (USD) | Capacity (kWh) | Method | Usable now (%) | Cycles/year | Energy value |
|---|---|---|---|---|---|---|
| Residential, light cycling | 9,000 | 10 | Measured | 92 | 180 | $0.20/kWh |
| Residential, higher cycling | 11,500 | 13.5 | Modeled | — | 300 | $0.24/kWh |
| Commercial, daily cycling | 55,000 | 60 | Modeled | — | 330 | $0.18/kWh |
Battery aging reduces usable kilowatt-hours, so each cycle delivers less value. If a 10 kWh unit falls from 100% to 85%, usable energy drops 1.5 kWh. When energy is worth $0.22/kWh and efficiency is 90%, that missing output can mean about $0.30 per cycle in foregone benefit. Over 250 cycles per year, the lost value approaches $75 annually, before considering growth in tariffs. Even small percentage changes matter when a system is dispatched or supports demand management.
Calendar aging reflects time, temperature, and state of charge; cycling aging reflects throughput. The calculator models calendar decline as exponential retention and cycling decline as percentage points per 1,000 cycles. For example, 2% calendar aging and 3% per 1,000 cycles at 250 cycles/year can push total fade near 3% annually. Higher depth-of-discharge and charging can accelerate this trend.
Upfront cost can be mapped to remaining usable capacity. If purchase cost is $9,000 and usable energy falls 12%, the proportional capital value lost is roughly $1,080. This framing helps compare warranties, operating strategies, and sizing options using a consistent dollars-per-usable-kWh perspective. It highlights the benefit of oversizing when space and interconnection allow.
Future lost energy value is discounted because money today is worth more than money later. With an 8% discount rate and a 7-year horizon, the net present value of annual losses can be meaningfully lower than the simple sum. This supports investment decisions and lifecycle budgeting. Sensitivity testing at 5% and 12% shows how capital cost of funds changes conclusions.
Many projects treat 70% usable capacity as a practical replacement trigger. By combining annual calendar loss and cycle-related loss, the tool estimates years until that threshold from today’s capacity. Pair the projection with your tariff, cycling plan, and warranty limits to schedule maintenance before performance constraints appear. Use the report downloads to document assumptions for stakeholders.
It estimates the financial impact of losing usable battery capacity, combining proportional capital value loss with discounted future value from reduced usable energy over time.
Use measured if you have a current usable percentage from the battery system. Use modeled when you only know aging assumptions and expected annual cycling.
Efficiency reduces the usable energy delivered per cycle. Lower efficiency increases the value lost from the same capacity fade because fewer kilowatt-hours reach the load.
A higher discount rate reduces the present value of future losses, lowering the NPV component. A lower discount rate makes future lost value weigh more in today’s estimate.
Many planning models use 70% usable capacity, but your trigger can differ based on performance requirements, warranty limits, and how tightly the system is sized.
Yes. Degradation depends on chemistry, temperature, depth-of-discharge, charging power, and controls. Use the calculator for comparisons, then validate with real telemetry.
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.