{
  "name": "DC-DC charger sizing JSON endpoint",
  "description": "Returns recommended DC-DC charger amperage, alternator input load, drive-day recovery, fuse floor, wire gauge hint, and watch-outs from battery, alternator, and drive-hour assumptions.",
  "publisher": {
    "name": "OffGridRVHub",
    "url": "https://www.offgridrvhub.com"
  },
  "source": {
    "endpoint": "https://www.offgridrvhub.com/tools/api/dc-dc-charger-size.json",
    "fullCalculator": "https://www.offgridrvhub.com/tools/dc-dc-charger-sizing-calculator",
    "assumptions": "https://www.offgridrvhub.com/tools/calculator-assumptions",
    "documentation": "https://www.offgridrvhub.com/tools/calculator-api"
  },
  "caveat": "This is a planning estimate for RV education and comparison. It is not electrical, plumbing, safety, or installation advice.",
  "input": {
    "batteryAh": 300,
    "batteryVoltage": 12,
    "batteryType": "lithium",
    "dailyEnergyGapWh": 1800,
    "driveHoursPerTravelDay": 2.5,
    "alternatorRatedAmps": 180,
    "alternatorReservePercent": 45,
    "targetChargeAmps": 40,
    "chargerEfficiencyPercent": 90,
    "oneWayCableLengthFt": 15,
    "maxVoltageDropPercent": 3,
    "alternatorType": "unknown"
  },
  "result": {
    "batteryChargeLimitAmps": 150,
    "alternatorSafeInputAmps": 99,
    "requestedAlternatorInputAmps": 44.4,
    "recommendedChargerAmps": 40,
    "recommendedChargerLabel": "40A DC-DC charger",
    "alternatorInputAmps": 44.4,
    "alternatorLoadPercent": 25,
    "effectiveChargeWatts": 432,
    "driveDayRecoveryWh": 1100,
    "driveHoursToReplaceGap": 4.2,
    "replacedPercentOfDailyGap": 61,
    "recommendedFuseAmps": 60,
    "wireGaugeHint": "4 AWG",
    "voltageDropPercent": 2.76,
    "verdictTitle": "40A helps, but drive time is the limiter",
    "verdictDetail": "A 40A charger recovers about 1,100Wh during the entered drive window, or 61% of the 1,800Wh daily gap.",
    "recommendedNextMove": "Use the recharge-time and solar calculators to cover the remaining daily gap before adding more battery capacity.",
    "watchOuts": [
      "This is a planning estimate. Confirm alternator output, vehicle wiring, fuse class, charger manual, battery charge limit, ignition trigger, ventilation, and warranty language before installation.",
      "The safe alternator allowance is intentionally conservative because headlights, HVAC fans, engine controls, trailer wiring, and heat can reduce real charging headroom.",
      "The alternator type is unknown. Verify whether the vehicle uses smart charging before choosing a charger or trigger method.",
      "The cable run is close to the voltage-drop target. Recheck the actual route length before buying copper.",
      "The entered drive window does not replace the daily energy gap by itself. Pair drive charging with solar, shore, generator charging, or lower loads."
    ]
  }
}