Battery Charge Manager
A battery health charge manager for longer battery lifespan. Set a low and a high charging threshold, and this page watches your device battery in your browser and tells you when to plug the charge cable in and when to unplug it, so the charge stays in the wear-friendly middle band instead of living at 0% or 100%.
Extend battery lifespan of phone/laptop/tablet with battery charging manager: keep the charge between your thresholds below. Note: battery manager updates only when page is in view.
Battery charging tips
- Avoid fast charging when hot - use low watts charger.
- Avoid full battery discharge to 0%.
- Avoid full battery charge to 100%.
- Once a month you may charge to 100% and discharge to 10% to calibrate charging level values.
- Store battery when not in use, in cool room tempretaure and 50% charging level.
- Set battery charge limit: iOS: Settings > Battery > Battery health & charging > 80% limit
- Android: Settings > Battery > Battery Protection (85% limit)
How to reduce battery environmental pollution
- Avoid non-rechargable, single-use, batteries when possible (e.g Alkaline battery).
- Prefer Nickel-metal (NiMh) over Nickel-cadmium (NiCd) batteries.
- Avoid Lead-acid battery usage, especially indoor usage. The lead metal is poisonous.
- Recycle all batteries.
- Reduce screen brightness.
- Use device low power settings: Windows: Settings > System > Power & battery
- Android: Settings > Battery > Power saving
- iOS: Settings > Battery > Low Power Mode
Rechargable battery types
| Battery type | Lifespan | Charging temperature range | Charging cycles | Common usage |
|---|---|---|---|---|
| Lithium-ion (Li-ion) and Lithium-ion polymer (LiPo) | 2-3 years | 5 to 45 °C (41 to 113 °F) | 300-500 | Mobile phones, laptops, electric cars |
| Nickel-metal hydride (NiMH) | 10 years | 0 to 50 °C (32 to 122 °F) | 500-2000 | AA/AAA rechargeble batteries, electric cars |
| Lead-acid | 3-12 years | -35 to 45 °C (-31 to 113 °F) | 500-800 | Car batteries, solar panel batteries |
Set your thresholds
Type a low threshold (typical: 20-35%) and a high threshold (typical: 80-90%). The defaults are 20% and 80% — the band most Li-ion batteries like living in.
Keep the page in view while charging
The manager reads the battery through your browser and updates only when the page is in view. When the charge drops to your low level it says to plug in; when charging reaches your high level it says to unplug.
Follow the charging tips
Avoid fast charging when hot, avoid discharging to 0% and charging to 100% every day, once a month run a full cycle to calibrate, and store an idle battery at 50% in a cool room.
How the charge manager works
- Why keep a lithium-ion battery between 20% and 80%?
- Li-ion and LiPo cells age fastest at the extremes: holding a pack at 100% or draining it to 0% stresses the electrodes. A middle band — low threshold around 20-35%, high threshold around 80-90% — is the common compromise between usable runtime and cycle life, which is why phone makers ship 80-85% charge limits.
- How does this page know my battery level?
- It reads the charge level and charging state through your browser's built-in Battery Status API — the same local signal your OS shows. The level never leaves your device; this page sends nothing anywhere.
- Which browsers can read the battery?
- Battery Status read is supported in Chrome on platforms that expose it (notably Windows, Linux, and Android). On browsers or systems without it, the page still works as a threshold setter plus the charging-tips reference and shows the not-supported notice.
- Why does it stop updating when I switch tabs?
- The underlying API delivers battery events only while the page is in view, so the manager updates when you are actually watching it. Keep this tab visible while you charge and it will alert you at your thresholds.
- Worked example
- With low = 20% and high = 80%: at 19% unplugged the manager says to plug the cable in; charging up to 80% (inclusive) while plugged in, it says charging is complete and to unplug. At 50% it simply shows the live level.
Privacy: battery level and charging state are read locally by your browser and are never collected, stored, or transmitted. Thresholds are not saved anywhere either. Tips are general battery-care guidance, not advice for a specific device.