EV Battery Replacement Reserve Calculator

Stay ahead of an out-of-warranty EV battery swap by turning replacement quotes into a monthly sinking fund. Enter the expected cost and timeline to see the monthly and annual savings required, present value today, and per-mile reserve needed after factoring in warranty mileage and any salvage credit.

Quote for a full traction battery replacement including labor and programming.
How many years you expect before the pack must be replaced outside warranty.
Optional — defaults to 3.00%. Reflects the opportunity cost of capital or investment return.
Optional — defaults to 12,000 miles per year. Used to compute per-mile reserve targets.
Optional — defaults to 0. Subtract the miles still covered by the factory battery warranty.
Optional — defaults to $0.00. Include rebates, warranty goodwill, or resale value of the old pack.

Estimates only. Verify replacement quotes, warranty terms, and salvage values with your manufacturer or certified repair center before committing funds.

Examples

  • Example 1 — $16,000.00 replacement, 6 years, 4.00% discount rate, 14,000 miles/year, 18,000 warranty miles, $1,500.00 salvage ⇒ Monthly reserve target: $201.39 USD/month • Annual reserve: $2,416.67 USD/year • Present value of future cost: $11,459.56 USD • Net cash needed after salvage: $14,500.00 USD • Per-mile accrual: $0.22 USD/mile • Miles covered in plan: 66,000.00 miles • Discount rate assumption: 4.00%
  • Example 2 — $11,000.00 replacement, 4 years, default discount, 12,000 miles/year, no warranty miles, no salvage ⇒ Monthly reserve target: $229.17 USD/month • Annual reserve: $2,750.00 USD/year • Present value of future cost: $9,773.36 USD • Net cash needed after salvage: $11,000.00 USD • Per-mile accrual: $0.23 USD/mile • Miles covered in plan: 48,000.00 miles • Discount rate assumption: 3.00%

FAQ

How do I include extended warranty coverage?

Set the years until replacement and warranty miles to reflect the extended coverage horizon. If the warranty covers the full cost, enter a salvage offset equal to the expected reimbursement so the net cash drops to zero.

What if I plan to finance the future battery?

Use the monthly reserve output as a benchmark for the loan payment you could afford. If you expect to borrow instead of save, compare the reserve amount to projected financing terms to gauge affordability.

Can I add installation downtime costs?

Yes. Add estimated rental car or rideshare expenses to the replacement cost so the reserve captures logistics while your vehicle is in the shop.

How often should I revisit the plan?

Review the calculator each year or every 10,000 miles to incorporate updated battery quotes, mileage, and warranty status.

Additional Information

  • Many EV warranties last 8 years or 100,000 miles; use the warranty miles input to exclude the protected portion when sizing your reserve.
  • Battery prices continue to fall—update the replacement cost annually to reflect quotes from your manufacturer or independent shops.
  • Including a discount rate lets you compare saving in cash versus investing in low-risk bonds until the replacement date.
  • If you expect to sell the vehicle before replacement, compare the reserve total to projected resale value to decide whether to pre-fund the swap.

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