{"id":2221,"date":"2026-01-29T23:36:52","date_gmt":"2026-01-29T21:36:52","guid":{"rendered":"https:\/\/nature-o.net\/?page_id=2221"},"modified":"2026-02-02T17:25:23","modified_gmt":"2026-02-02T15:25:23","slug":"home-battery-backup-runtime-calculator","status":"publish","type":"page","link":"https:\/\/nature-o.net\/?page_id=2221","title":{"rendered":"Home Battery Backup Runtime Calculator"},"content":{"rendered":"\n<div class=\"eco-tool wp-block-group\" id=\"eco-tool-battery-1f92c\">\n  <div class=\"eco-tool__header\">\n    <h2 class=\"eco-tool__title\">Home Battery Backup Runtime Calculator<\/h2>\n    <p class=\"eco-tool__lead\">\n      Estimate how long a home battery or portable power station could run your essentials during an outage. Results are approximate.\n    <\/p>\n  <\/div>\n\n  <form class=\"eco-tool__form\" id=\"eco-bat-form-1f92c\" novalidate>\n    <div class=\"eco-tool__grid3\">\n      <div class=\"eco-tool__field\">\n        <label class=\"eco-tool__label\" for=\"eco-bat-unit-1f92c\">Battery capacity (unit)<\/label>\n        <select class=\"eco-tool__input\" id=\"eco-bat-unit-1f92c\">\n          <option value=\"wh\" selected>Wh<\/option>\n          <option value=\"kwh\">kWh<\/option>\n        <\/select>\n        <div class=\"eco-tool__hint\">Power stations often list Wh; home batteries often list kWh.<\/div>\n      <\/div>\n\n      <div class=\"eco-tool__field\">\n        <label class=\"eco-tool__label\" for=\"eco-bat-cap-1f92c\">Battery capacity<\/label>\n        <input class=\"eco-tool__input\" id=\"eco-bat-cap-1f92c\" type=\"number\" min=\"0\" step=\"10\" value=\"1000\" inputmode=\"numeric\" \/>\n        <div class=\"eco-tool__hint\">Example: 1000 Wh (1 kWh).<\/div>\n      <\/div>\n\n      <div class=\"eco-tool__field\">\n        <label class=\"eco-tool__label\" for=\"eco-bat-loadmode-1f92c\">Load input method<\/label>\n        <select class=\"eco-tool__input\" id=\"eco-bat-loadmode-1f92c\">\n          <option value=\"simple\" selected>Enter average watts<\/option>\n          <option value=\"appliances\">Pick common appliances<\/option>\n        <\/select>\n        <div class=\"eco-tool__hint\">Use \u201cappliances\u201d if you\u2019re not sure about watts.<\/div>\n      <\/div>\n\n      <div class=\"eco-tool__field\">\n        <label class=\"eco-tool__label\" for=\"eco-bat-watts-1f92c\">Average load<br>(W)<\/label>\n        <input class=\"eco-tool__input\" id=\"eco-bat-watts-1f92c\" type=\"number\" min=\"0\" step=\"1\" value=\"120\" inputmode=\"numeric\" \/>\n        <div class=\"eco-tool__hint\">Example: 120 W (router + lights + phone charging).<\/div>\n      <\/div>\n\n      <div class=\"eco-tool__field eco-tool__field--wide\" id=\"eco-bat-appliance-wrap-1f92c\" hidden>\n        <label class=\"eco-tool__label\">Common appliances (toggle on)<\/label>\n        <div class=\"eco-tool__appliances\">\n          <label class=\"eco-tool__tick\"><input type=\"checkbox\" data-w=\"10\"> Wi-Fi router (10 W)<\/label>\n          <label class=\"eco-tool__tick\"><input type=\"checkbox\" data-w=\"8\"> Phone charging (8 W)<\/label>\n          <label class=\"eco-tool__tick\"><input type=\"checkbox\" data-w=\"15\"> LED lights (15 W)<\/label>\n          <label class=\"eco-tool__tick\"><input type=\"checkbox\" data-w=\"60\"> Laptop (60 W)<\/label>\n          <label class=\"eco-tool__tick\"><input type=\"checkbox\" data-w=\"100\"> TV (100 W)<\/label>\n          <label class=\"eco-tool__tick\"><input type=\"checkbox\" data-w=\"150\"> Refrigerator (avg 150 W)<\/label>\n          <label class=\"eco-tool__tick\"><input type=\"checkbox\" data-w=\"700\"> Microwave (700 W)<\/label>\n          <label class=\"eco-tool__tick\"><input type=\"checkbox\" data-w=\"1200\"> Kettle\/boiler (1200 W)<\/label>\n        <\/div>\n        <div class=\"eco-tool__hint\">Appliance watts are rough averages.<\/div>\n      <\/div>\n    <\/div>\n\n    <div class=\"eco-tool__actions\">\n      <button type=\"button\" class=\"wp-element-button eco-tool__btn\" id=\"eco-bat-calc-1f92c\">Calculate<\/button>\n      <button type=\"button\" class=\"wp-element-button eco-tool__btn eco-tool__btn--ghost\" id=\"eco-bat-reset-1f92c\">Reset<\/button>\n      <div class=\"eco-tool__error\" id=\"eco-bat-error-1f92c\" aria-live=\"polite\"><\/div>\n    <\/div>\n  <\/form>\n\n  <div class=\"eco-tool__result\" id=\"eco-bat-result-1f92c\" hidden>\n    <h3 class=\"eco-tool__subtitle\">Result<\/h3>\n\n    <div class=\"eco-tool__cards\">\n      <div class=\"eco-tool__card\">\n        <div class=\"eco-tool__metric-label\">Estimated runtime<\/div>\n        <div class=\"eco-tool__metric-value\" id=\"eco-bat-runtime-1f92c\">\u2014<\/div>\n        <div class=\"eco-tool__metric-sub\" id=\"eco-bat-runtime-sub-1f92c\"><\/div>\n      <\/div>\n\n      <div class=\"eco-tool__card\">\n        <div class=\"eco-tool__metric-label\">Usable energy (estimate)<\/div>\n        <div class=\"eco-tool__metric-value\" id=\"eco-bat-energy-1f92c\">\u2014<\/div>\n        <div class=\"eco-tool__metric-sub\" id=\"eco-bat-energy-sub-1f92c\"><\/div>\n      <\/div>\n    <\/div>\n\n    <div class=\"eco-tool__card eco-tool__card--wide\">\n      <div class=\"eco-tool__metric-label\">Practical tips<\/div>\n      <div class=\"eco-tool__steps\" id=\"eco-bat-tips-1f92c\"><\/div>\n    <\/div>\n\n    <p class=\"eco-tool__note\">\n      Real runtime varies with battery age, temperature, and inverter characteristics.\n    <\/p>\n  <\/div>\n\n  <details class=\"eco-tool__details\">\n    <summary class=\"eco-tool__summary\">Formula<\/summary>\n    <div class=\"eco-tool__details-body\">\n      <p class=\"eco-tool__text\">\n        Usable energy \u2248 capacity \u00d7 85%. Runtime (hours) \u2248 usable energy (Wh) \u00f7 average load (W).\n      <\/p>\n    <\/div>\n  <\/details>\n<\/div>\n\n<style>\n.eco-tool{ border:1px solid rgba(0,0,0,.12); border-radius:12px; padding:16px; }\n.eco-tool__header{ margin-bottom:12px; }\n.eco-tool__title{ margin:0 0 8px; }\n.eco-tool__lead{ margin:0; opacity:.9; }\n\n.eco-tool__form{ margin-top:12px; }\n.eco-tool__grid3{ display:grid; grid-template-columns:1fr; gap:16px; }\n@media (min-width:860px){ .eco-tool__grid3{ grid-template-columns:1fr 1fr 1fr; } }\n\n.eco-tool__field{ display:flex; flex-direction:column; gap:6px; }\n.eco-tool__field--wide{ grid-column:1\/-1; }\n\n.eco-tool__label{ font-weight:600; }\n.eco-tool__input{\n  width:100%; height:44px; padding:0 12px;\n  border:1px solid rgba(0,0,0,.20); border-radius:10px; background:#fff;\n  box-sizing:border-box; font:inherit;\n}\n.eco-tool select.eco-tool__input{\n  appearance:none; -webkit-appearance:none; line-height:44px; padding-right:40px;\n  background-image:\n    linear-gradient(45deg, transparent 50%, rgba(0,0,0,.60) 50%),\n    linear-gradient(135deg, rgba(0,0,0,.60) 50%, transparent 50%);\n  background-position: calc(100% - 18px) 50%, calc(100% - 12px) 50%;\n  background-size:6px 6px; background-repeat:no-repeat;\n}\n.eco-tool__hint{ font-size:.92em; opacity:.78; min-height:38px; }\n\n.eco-tool__actions{ display:flex; flex-wrap:wrap; gap:10px; align-items:center; margin-top:16px; }\n.eco-tool__btn{ padding:10px 22px; }\n.eco-tool__btn--ghost{ background:transparent !important; border:1px solid rgba(0,0,0,.20) !important; }\n.eco-tool__btn--ghost:hover, .eco-tool__btn--ghost:focus{\n  background:rgba(0,0,0,.06) !important; border-color:rgba(0,0,0,.35) !important;\n}\n.eco-tool__error{ min-height:1.2em; font-weight:600; flex:1 1 240px; }\n\n.eco-tool__result{ margin-top:16px; }\n.eco-tool__subtitle{ margin:0 0 10px; }\n\n.eco-tool__cards{ display:grid; gap:10px; grid-template-columns:1fr; }\n@media (min-width:860px){ .eco-tool__cards{ grid-template-columns:1fr 1fr; } }\n\n.eco-tool__card{ border:1px solid rgba(0,0,0,.12); border-radius:12px; padding:12px; }\n.eco-tool__card--wide{ margin-top:10px; }\n\n.eco-tool__metric-label{ opacity:.85; font-weight:600; }\n.eco-tool__metric-value{ font-size:1.7em; font-weight:900; margin-top:6px; line-height:1.1; }\n.eco-tool__metric-sub{ opacity:.85; margin-top:6px; }\n\n.eco-tool__steps{ display:grid; gap:8px; margin-top:10px; }\n.eco-tool__step{\n  border:1px solid rgba(0,0,0,.10);\n  border-radius:10px;\n  padding:10px;\n  background: rgba(0,0,0,.02);\n}\n\n.eco-tool__appliances{\n  display:grid;\n  grid-template-columns: 1fr;\n  gap:8px;\n  padding:10px 12px;\n  border:1px solid rgba(0,0,0,.12);\n  border-radius:10px;\n  background: rgba(0,0,0,.02);\n}\n@media (min-width:860px){\n  .eco-tool__appliances{ grid-template-columns: 1fr 1fr; }\n}\n.eco-tool__tick{ display:flex; gap:10px; align-items:center; }\n.eco-tool__tick input{ transform: translateY(1px); }\n\n.eco-tool__note{ margin:10px 0 0; opacity:.9; }\n.eco-tool__details{ margin-top:14px; }\n.eco-tool__summary{ cursor:pointer; font-weight:700; }\n.eco-tool__details-body{ margin-top:10px; }\n.eco-tool__text{ margin:0; }\n<\/style>\n\n<script>\n(function(){\n  const S = \"1f92c\";\n  const el = (id) => document.getElementById(id + \"-\" + S);\n\n  const unitEl = el(\"eco-bat-unit\");\n  const capEl = el(\"eco-bat-cap\");\n  const loadModeEl = el(\"eco-bat-loadmode\");\n  const wattsEl = el(\"eco-bat-watts\");\n\n  const appWrap = el(\"eco-bat-appliance-wrap\");\n  const calcBtn = el(\"eco-bat-calc\");\n  const resetBtn = el(\"eco-bat-reset\");\n  const errorEl = el(\"eco-bat-error\");\n\n  const resultEl = el(\"eco-bat-result\");\n  const runtimeEl = el(\"eco-bat-runtime\");\n  const runtimeSubEl = el(\"eco-bat-runtime-sub\");\n  const energyEl = el(\"eco-bat-energy\");\n  const energySubEl = el(\"eco-bat-energy-sub\");\n  const tipsEl = el(\"eco-bat-tips\");\n\n  const appChecks = appWrap.querySelectorAll('input[type=\"checkbox\"]');\n\n  \/\/ Fixed averages (hidden from user)\n  const EFFICIENCY = 0.85; \/\/ 85%\n  const SURGE = 1.0;       \/\/ removed from UI (average)\n\n  function setError(msg){ errorEl.textContent = msg || \"\"; }\n  function n(v){ return Number(v); }\n\n  function fmt1(x){\n    const v = Math.round(x * 10) \/ 10;\n    return v.toLocaleString(undefined, { minimumFractionDigits: 1, maximumFractionDigits: 1 });\n  }\n\n  function getCapacityWh(){\n    const cap = n(capEl.value);\n    if (!Number.isFinite(cap) || cap < 0) return null;\n    return unitEl.value === \"kwh\" ? cap * 1000 : cap;\n  }\n\n  function getLoadW(){\n    if (loadModeEl.value === \"simple\"){\n      const w = n(wattsEl.value);\n      if (!Number.isFinite(w) || w < 0) return null;\n      return w;\n    }\n    let sum = 0;\n    appChecks.forEach(ch => {\n      if (ch.checked) sum += n(ch.getAttribute(\"data-w\")) || 0;\n    });\n    return sum;\n  }\n\n  function setLoadModeUI(){\n    if (loadModeEl.value === \"appliances\"){\n      appWrap.hidden = false;\n      wattsEl.disabled = true;\n    } else {\n      appWrap.hidden = true;\n      wattsEl.disabled = false;\n    }\n  }\n\n  function step(t){ return `<div class=\"eco-tool__step\">${t}<\/div>`; }\n\n  function calculate(){\n    setError(\"\");\n\n    const capWh = getCapacityWh();\n    if (capWh === null){\n      setError(\"Please enter a valid battery capacity (0 or more).\");\n      resultEl.hidden = true;\n      return;\n    }\n\n    const loadW = getLoadW();\n    if (loadW === null){\n      setError(\"Please enter a valid load (0 or more).\");\n      resultEl.hidden = true;\n      return;\n    }\n    if (loadModeEl.value === \"appliances\" && loadW === 0){\n      setError(\"Select at least one appliance, or switch to \u201cEnter average watts\u201d.\");\n      resultEl.hidden = true;\n      return;\n    }\n    if (loadW === 0){\n      setError(\"Load must be greater than 0.\");\n      resultEl.hidden = true;\n      return;\n    }\n\n    const usableWh = capWh * EFFICIENCY;\n    const effectiveLoadW = loadW * SURGE;\n\n    const hours = usableWh \/ effectiveLoadW;\n    const days = hours \/ 24;\n\n    runtimeEl.textContent = hours >= 24 ? `${fmt1(days)} days` : `${fmt1(hours)} hours`;\n    runtimeSubEl.textContent =\n      `Usable energy ~${Math.round(usableWh).toLocaleString()} Wh (capacity \u00d7 85%), load ~${Math.round(effectiveLoadW).toLocaleString()} W.`;\n\n    energyEl.textContent = `${Math.round(usableWh).toLocaleString()} Wh`;\n    energySubEl.textContent = `Estimated usable energy from ${Math.round(capWh).toLocaleString()} Wh capacity.`;\n\n    const tips = [];\n    tips.push(\"Prioritize essentials: lighting, communication, and refrigeration (if needed).\");\n    tips.push(\"Avoid high-watt devices (kettle, heater, microwave) unless you have a very large battery.\");\n    tips.push(\"Reduce load: turn off standby devices and lower screen brightness.\");\n    tips.push(\"Cold temperatures can reduce battery performance\u2014keep batteries within their recommended range.\");\n    tipsEl.innerHTML = tips.map(step).join(\"\");\n\n    resultEl.hidden = false;\n  }\n\n  function reset(){\n    setError(\"\");\n    unitEl.value = \"wh\";\n    capEl.value = \"1000\";\n    loadModeEl.value = \"simple\";\n    wattsEl.value = \"120\";\n    appChecks.forEach(ch => ch.checked = false);\n    setLoadModeUI();\n    resultEl.hidden = true;\n  }\n\n  loadModeEl.addEventListener(\"change\", setLoadModeUI);\n  calcBtn.addEventListener(\"click\", calculate);\n  resetBtn.addEventListener(\"click\", reset);\n\n  setLoadModeUI();\n})();\n<\/script>\n","protected":false},"excerpt":{"rendered":"<p>Home Battery Backup Runtime Calculator Estimate how long a home battery or portable power station could run your essentials during an outage. Results are approximate. Battery capacity (unit) WhkWh Power&hellip;<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":2452,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_sitemap_exclude":false,"_sitemap_priority":"","_sitemap_frequency":"","footnotes":""},"_links":{"self":[{"href":"https:\/\/nature-o.net\/index.php?rest_route=\/wp\/v2\/pages\/2221"}],"collection":[{"href":"https:\/\/nature-o.net\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/nature-o.net\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/nature-o.net\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/nature-o.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2221"}],"version-history":[{"count":7,"href":"https:\/\/nature-o.net\/index.php?rest_route=\/wp\/v2\/pages\/2221\/revisions"}],"predecessor-version":[{"id":2288,"href":"https:\/\/nature-o.net\/index.php?rest_route=\/wp\/v2\/pages\/2221\/revisions\/2288"}],"up":[{"embeddable":true,"href":"https:\/\/nature-o.net\/index.php?rest_route=\/wp\/v2\/pages\/2452"}],"wp:attachment":[{"href":"https:\/\/nature-o.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2221"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}