Home Charging Time Estimator

ANA›Life Services Authority›National Calculator Authority›Home Charging Time Estimator

.calc-container { max-width: 640px; margin: 2rem 0; padding: 1.5rem; background: #fff; border: 1px solid #ddd; border-radius: 8px; box-shadow: 0 1px 3px rgba(0,0,0,0.06); font-family: system-ui, -apple-system, sans-serif; } .calc-container h3 { font-family: Georgia, serif; font-size: 1.15rem; color: #1a1a1a; margin-bottom: 1rem; padding-bottom: 0.5rem; border-bottom: 2px solid var(--ac, #3d5a80); } .calc-row { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 0.75rem; flex-wrap: wrap; } .calc-row label { min-width: 160px; font-size: 0.9rem; color: #333; font-weight: 500; } .calc-row input[type="number"], .calc-row select { flex: 1; min-width: 120px; max-width: 200px; padding: 0.5rem 0.6rem; border: 1px solid #ccc; border-radius: 4px; font-size: 0.9rem; font-family: system-ui, sans-serif; color: #1a1a1a; background: #fafaf8; } .calc-row input:focus, .calc-row select:focus { outline: none; border-color: var(--ac, #3d5a80); box-shadow: 0 0 0 2px rgba(26,74,138,0.12); } .calc-row .unit { font-size: 0.82rem; color: #888; min-width: 30px; } .calc-btn { display: inline-block; margin-top: 0.5rem; padding: 0.55rem 1.5rem; background: var(--ac, #3d5a80); color: #fff; border: none; border-radius: 4px; font-size: 0.9rem; font-weight: 600; cursor: pointer; font-family: system-ui, sans-serif; } .calc-btn:hover { opacity: 0.9; } .calc-result { margin-top: 1.25rem; padding: 1rem 1.25rem; background: #f0f6fc; border-left: 3px solid var(--ac, #3d5a80); border-radius: 0 6px 6px 0; display: none; } .calc-result.visible { display: block; } .calc-result-label { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; color: #666; margin-bottom: 0.25rem; } .calc-result-value { font-size: 1.6rem; font-weight: 700; color: var(--ac, #3d5a80); } .calc-result-detail { font-size: 0.85rem; color: #555; margin-top: 0.5rem; line-height: 1.5; } .calc-note { margin-top: 1rem; font-size: 0.8rem; color: #888; font-style: italic; } .calc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.75rem; margin-top: 0.75rem; } .calc-grid-item { padding: 0.6rem 0.8rem; background: #f8f9fa; border-radius: 4px; border: 1px solid #eee; } .calc-grid-item .label { font-size: 0.75rem; color: #888; text-transform: uppercase; letter-spacing: 0.04em; } .calc-grid-item .value { font-size: 1.1rem; font-weight: 600; color: #1a1a1a; } @media (max-width: 720px) { .calc-row { flex-direction: column; align-items: flex-start; gap: 0.3rem; } .calc-row label { min-width: auto; } .calc-row input[type="number"], .calc-row select { max-width: 100%; width: 100%; } .calc-grid { grid-template-columns: 1fr; } } .calc-chart { margin: 1rem 0; text-align: center; } .calc-chart svg { max-width: 100%; height: auto; } .calc-chart-legend { display: flex; flex-wrap: wrap; justify-content: center; gap: 0.6rem 1.2rem; margin-top: 0.6rem; font-size: 0.8rem; color: #555; } .calc-chart-legend span { display: inline-flex; align-items: center; gap: 0.3rem; } .calc-chart-legend i { display: inline-block; width: 10px; height: 10px; border-radius: 2px; font-style: normal; } .calc-related { max-width: 640px; margin: 2rem 0 1rem; padding: 1.25rem 1.5rem; background: #f8f9fa; border: 1px solid #e8e8e8; border-radius: 8px; } .calc-related h3 { font-family: Georgia, serif; font-size: 1rem; color: #1a1a1a; margin: 0 0 0.75rem; padding-bottom: 0.4rem; border-bottom: 2px solid var(--ac, #3d5a80); } .calc-related-list { list-style: none; padding: 0; margin: 0 0 0.75rem; display: grid; grid-template-columns: 1fr 1fr; gap: 0.4rem 1.5rem; } .calc-related-list li a { font-size: 0.88rem; color: var(--ac, #3d5a80); text-decoration: none; } .calc-related-list li a:hover { text-decoration: underline; } .calc-browse-all { margin: 0.5rem 0 0; font-size: 0.9rem; font-weight: 600; } .calc-browse-all a { color: var(--ac, #3d5a80); text-decoration: none; } .calc-browse-all a:hover { text-decoration: underline; } @media (max-width: 720px) { .calc-related-list { grid-template-columns: 1fr; } }

Home Charging Time Estimator

Estimate how long it will take to fully charge your electric vehicle at home based on your charger type, battery size, and current charge level.

Battery Capacity (kWh)

Total usable battery capacity of your EV (check your owner's manual or manufacturer specs).

Current State of Charge (%)

How charged is your battery right now? (0–99%)

Target State of Charge (%)

What charge level do you want to reach? (1–100%; 80% recommended for daily use to preserve battery health)

Charger Level

-- Select Charger Level -- Level 1 – 120V / 12A (1.44 kW) Level 1 – 120V / 16A (1.92 kW) Level 2 – 240V / 16A (3.84 kW) Level 2 – 240V / 24A (5.76 kW) Level 2 – 240V / 32A (7.68 kW) — Most Common Home EVSE Level 2 – 240V / 40A (9.6 kW) Level 2 – 240V / 48A (11.52 kW) Custom / Enter Power Manually

Custom Charger Output Power (kW)

Enter the actual AC power output of your EVSE or wall charger in kilowatts.

Vehicle On-Board Charger (OBC) Limit (kW) (optional)

Your EV's on-board charger may accept less power than your EVSE provides. Leave blank if unknown (we'll use the EVSE power). Common values: 3.3, 6.6, 7.2, 11, 22 kW.

Charging Efficiency (%)

AC-to-battery charging efficiency (typically 85–95%). Default: 90%.

Calculate Charging Time

function homUpdateChargerInfo() { var sel = document.getElementById('hom-charger-level').value; var note = document.getElementById('hom-charger-note'); var customField = document.getElementById('hom-custom-power-field');

if (sel === 'custom') { customField.style.display = 'block'; note.textContent = 'Enter your charger's rated output power below.'; } else { customField.style.display = 'none'; if (sel === '') { note.textContent = ''; } else { var parts = sel.split('_'); var voltage = parts[1]; var amps = parts[2]; var kw = (parseFloat(voltage) * parseFloat(amps) / 1000).toFixed(2); note.textContent = voltage + 'V × ' + amps + 'A = ' + kw + ' kW rated output.'; } } }

function homGetChargerPower() { var sel = document.getElementById('hom-charger-level').value; if (sel === 'custom') { return parseFloat(document.getElementById('hom-custom-power').value); } if (sel === '') return NaN; var parts = sel.split('_'); return (parseFloat(parts[1]) * parseFloat(parts[2])) / 1000; }

function homFormatTime(hours) { var totalMinutes = Math.round(hours * 60); var h = Math.floor(totalMinutes / 60); var m = totalMinutes % 60; var parts = []; if (h > 0) parts.push(h + ' hr' + (h !== 1 ? 's' : '')); if (m > 0) parts.push(m + ' min' + (m !== 1 ? 's' : '')); if (parts.length === 0) return 'Less than 1 minute'; return parts.join(' '); }

function homCalc() { var resultDiv = document.getElementById('hom-result'); resultDiv.style.display = 'block'; resultDiv.className = 'calc-result';

// --- Gather inputs --- var batteryCapacity = parseFloat(document.getElementById('hom-battery-capacity').value); var currentSOC = parseFloat(document.getElementById('hom-current-soc').value); var targetSOC = parseFloat(document.getElementById('hom-target-soc').value); var chargerPower = homGetChargerPower(); var obcLimit = parseFloat(document.getElementById('hom-onboard-charger').value); var efficiency = parseFloat(document.getElementById('hom-efficiency').value);

// --- Validation --- var errors = [];

if (isNaN(batteryCapacity) || batteryCapacity 200) { errors.push('Battery capacity should be between 10 and 200 kWh for a typical EV.'); }

if (isNaN(currentSOC) || currentSOC 99) { errors.push('Current state of charge must be between 0% and 99%.'); }

if (isNaN(targetSOC) || targetSOC 100) { errors.push('Target state of charge must be between 1% and 100%.'); }

if (!isNaN(currentSOC) && !isNaN(targetSOC) && targetSOC 100) { errors.push('Charging efficiency must be between 50% and 100%.'); }

if (errors.length > 0) { resultDiv.className = 'calc-result calc-error'; resultDiv.innerHTML = 'Please fix the following:' + errors.map(function(e){ return ''; }).join('') + ''; return; }

// --- Core Formula --- // Effective charger power = min(EVSE power, OBC limit) if OBC is provided var evseKw = chargerPower; var effectiveKw = evseKw; var obcNote = ''; if (!isNaN(obcLimit) && obcLimit > 0) { effectiveKw = Math.min(evseKw, obcLimit); if (obcLimit '; html += 'Battery Capacity' + batteryCapacity.toFixed(1) + ' kWh'; html += 'Charge Needed' + currentSOC.toFixed(0) + '% → ' + targetSOC.toFixed(0) + '% (' + socDiff.toFixed(0) + '% = ' + energyToStore.toFixed(2) + ' kWh into battery)'; html += 'EVSE Rated Power' + evseKw.toFixed(2) + ' kW'; html += 'Effective Charging Power' + effectiveKw.toFixed(2) + ' kW'; html += 'Charging Efficiency' + efficiency.toFixed(0) + '%'; html += 'Energy Drawn from Wall' + energyFromWall.toFixed(2) + ' kWh'; html += 'Estimated Electricity Cost~$' + costPer10kWh.toFixed(2) + ' (at $0.16/kWh avg)'; html += 'Charging Time' + homFormatTime(chargingTimeHours) + ' (' + chargingTimeHours.toFixed(2) + ' hrs)'; html += '';

html += ''; if (obcNote) html += obcNote; if (targetSOC > 80) { html += ''; } if (chargingTimeHours > 12) { html += ''; } if (effectiveKw

#### Formula

Step 1 – Energy needed in battery (kWh): Ebattery = Battery Capacity (kWh) × (Target SOC% − Current SOC%) / 100

Step 2 – Energy drawn from the wall (kWh): Ewall = Ebattery / Charging Efficiency Accounts for heat losses in the on-board charger and wiring.

Step 3 – Effective charger power (kW): Peff = min(EVSE Power, OBC Limit) The actual charging rate is limited by whichever is lower: your wall charger or your vehicle's on-board charger.

Step 4 – Charging time (hours): Time (hrs) = Ewall / Peff

EVSE Power: P (kW) = Voltage (V) × Amperage (A) / 1000

#### Assumptions & References

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