A battery and an inverter do not last 25 years. This is how Amperage charges for replacing them:
- What it chargesthe battery's replacement (year 10 if the warranty is unknown) and the inverter's (year 12), at today's prices, no future price falls assumed.
- Analysis flowthe Replacement Costs card on Solar & Battery, and the same four levers in Scenario Settings on Recommendation.
- Proposal flowthe on/off toggle and year sit on Solar Design (inverter) and Battery Design (battery); Pricing carries the $ figure for each.
- Blank fields auto-deriveno year set follows the battery's warranty; no cost set prices the battery from its quoted price and the inverter from the system size.
- Where it shows upa marked dip on the Output cashflow chart, a Replacement Costs table in the PDF proposal, and inside payback, NPV and every sizing-matrix cell.
- Never in the quotethe upfront price you hand the customer is untouched; replacement is a mid-life cost inside the long-run numbers only.
Off by default on every project. Nothing changes until you switch it on.
A battery does not usually last 25 years, and neither does an inverter. Both used to be modelled as if they ran the whole analysis for free, which quietly overstated payback and NPV on any long-run number. Amperage can now charge for replacing each one in the year it falls due, at today's prices, so the lifetime figures reflect what actually happens on site.
What gets charged, and when
Two mid-life outlays can be modelled: the battery, replaced at its warranty year (year 10 if the warranty is not known), and the inverter, replaced at year 12. Both are priced at today's rates, no allowance for future price falls. Each is charged in the exact year it falls due, not spread across the analysis or amortised, so a battery replaced in year 10 shows up as a real cost in year 10 and nowhere else.
Where the controls live
In an Analysis project the levers sit in the Replacement Costs card on the Solar & Battery step, and the same four fields (battery year, battery $/kWh, inverter year, inverter $/W) also appear in the Scenario Settings modal on Recommendation, so you can adjust them without leaving the sizing view.
In a Proposal project the same feature is split across the stages that already own each piece. Solar Design carries the inverter toggle and its replacement year in the right rail. Battery Design carries the battery toggle and year the same way. Pricing is where the dollar figures live: a year and an absolute $ override per item, so the cost the customer sees quoted for the battery or inverter can double as the replacement cost basis. The Output page's Adjust Assumptions modal edits everything from one place, regardless of which flow the project is in.
Leave a field blank and it fills itself in
- Battery replacement year blank follows the battery's own warranty term. Only if the warranty is unknown does it fall back to year 10.
- Battery replacement cost blank derives its $/kWh from the price you quoted for that battery, so the replacement is priced the same way the original purchase was.
- Inverter replacement year defaults to 12 unless you set it.
- Inverter replacement cost blank derives its $/W against the system size.
That means you can switch the feature on and get a sensible number immediately, then override any individual field once you have a firmer figure.
Where the cost shows up
- The Output cashflow chart marks the year with a visible dip and a label, for example "Battery replaced · -$399k", so the customer can see exactly what causes the drop.
- The PDF proposal includes a Replacement Costs table that lists each item, its year and its cost, right under the cashflow the numbers came from.
- Every payback, NPV and break-even figure already has the charge folded in, and it feeds every cell of the sizing matrix, so scenarios are compared on the same basis whether or not replacement is switched on.
Off by default
Replacement costs start switched off on every project, new or old. Nothing changes in any number until you open the Replacement Costs card (or Adjust Assumptions on Output) and turn it on yourself. Turning it on will move payback and NPV, usually a small step later and lower, because a cost that was previously free of charge is now accounted for.