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1Clear out junk files and repair common Windows errors2Scan for outdated or missing drivers - takes under a minute3Repair Windows errors before they cause bigger problemsPower an ESP32 from a battery only through an input and regulator path rated for the battery’s full voltage range. To extend runtime, lower the project’s average battery-side current by reducing radio use, sleeping between tasks, and powering down unused peripherals. Estimate runtime from measured current across a representative work-and-sleep cycle—not from the ESP32 chip’s sleep specification alone.
Check the board’s power input before connecting a battery
The safe connection depends on the exact ESP32 module or development board. For the ESP32-WROOM-32 module, Espressif specifies a supply range of 3.0–3.6 V, with 3.3 V typical, and calls for an external supply capable of delivering at least 0.5 A. Those are module specifications, not a universal input rule for every ESP32-family board. Check your board’s documentation for its power connector, pinout, regulator, and permitted input range before wiring a cell. See the ESP32-WROOM-32 datasheet.
A battery’s nominal voltage does not tell the whole story: its voltage changes as it charges and discharges. For example, Adafruit lists a 3.7 V, 2500 mAh lithium-polymer battery whose output ranges from 4.2 V fully charged to 3.7 V, with about 10 Wh of energy. Since 4.2 V is above the ESP32-WROOM-32’s 3.6 V maximum supply, do not connect that cell directly to the module’s 3.3 V rail. Use a documented battery input on the board or a conversion circuit rated for the cell’s complete voltage range. The product listing does not establish that the battery is compatible with every board’s charging or protection circuitry. Adafruit battery listing.
Match the complete power path
When choosing a battery-powered board or supply, check the battery’s chemistry and voltage range alongside the board’s allowed input. For a regulator or buck-boost converter, verify input and output ranges, peak-current capability, quiescent current, and efficiency at your project’s actual load profile. If the board has an integrated charger, confirm that it supports the chosen cell and provides the protection the design requires. A low-quiescent-current regulator may help a design that spends much of its time asleep, but no one converter topology suits every battery and board.
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- Charging Method: The recommended charging current is 0.6A, the maximum does not exceed 1.5A. The discharge current is recommended 0.6A, and the maximum does not exceed 1.5A
- Overcharge Protection: When charging the battery, when the voltage reaches the highest battery voltage (4.2V), the protection board will automatically power off and shut down, indicating that it will not continue to charge when fully charged, forms overcharge protection
- Over-discharge Protection: When the battery is about to run out and the voltage is as low as 3.0V, the protection board will also be turned off and can no longer be discharged, forming an over-discharge protection effect
- Short Circuit Protection: When an accidental short circuit occurs, the protection board will automatically shut down within a few milliseconds and will not be powered on again. Note that the cell is short-circuited (not through the protection board). The protection board will also fail due to continuous high current, or the components are heated and damaged
- Widely Application: With JST 1.25 plug, these lithium polymer batteries can be used for development board whose plug is SH1.25-2, such as ESP32 LoRa V3, ESP32 LoRa V4, Wireless Tracker, Mesh Node T114, Mesh Node T096 and electronic devices
Estimate runtime from the whole project’s average current
Start with the battery’s rated capacity and the average current drawn at the battery over a representative operating cycle:
Ideal runtime in hours ≈ battery capacity in mAh ÷ average battery current in mA
Rank #2
- Battery Specifications：Dimensions: 36*10*65mm/ 1.42*0.39*2.56inch;Battery Weight(Single): 49g; Capacity: 3000mAh; Plug: JST1.25; Discharge Rate: 1C. Make Sure Device Polarity Matches with Battery Pack Connector Before Purchase.1.Battery Size; 2.Connector Model;3.Connector Size; 4.Connector Polarity - THIS IS NOT UNIVERSAL!!! (It will cause a shortage if the polarity of the battery connector does not match your device.)
- Reliable Performance: Our 3.7 volt rechargeable lithium polymer battery provides reliable performance with long life. It is no fire, no explosion or no leakage after vibration and collision.Each lipo battery comes equipped with a built-in protection board that prevents overcharging, over-discharging, overcurrent, overheating, and short circuits. Enjoy peace of mind while using our lithium polymer battery, knowing that it is designed with advanced safety features.
- Application：Our batteries are perfect for ESP3 projects or a small Internet of Things (IoT) project. Also suitable for battery replacement of DIY 3.7V electronic products, mobile energy storage, power supply, LED light, wireless Bluetooth game headset, Bluetooth speaker, outdoor video and audio electronic scale, GPS Watch recorder, USB Fan tester, dash cam controller, gaming controller, electric toy car, mouse and keyboard, Wi-Fi smart home system, digital camera, e-book, and so on.
- Storage & Usage：When storing lithium polymer batteries for a long time, please keep the battery in a state of 40%-60%. We recommend to charge the battery every 3 months receipt of the battery and maintain the voltage 3.7-4.0V. Store battery in cool and dry place.
- Easy Installation with Micro JST1.25 Connector: The 3000mAh lithium polymer battery feature a Micro JST1.25 connector and a wire of about 70mm, making installation simple and convenient. Upgrade your devices effortlessly with our user-friendly design, ensuring a secure connection for maximum performance.(NOTE!!! The maximum operating current of this battery is only about 1.5A, Can Not be used for unmanned vehicles, model aircraft or other products that require high current)
Include boot, sensor sampling, display or LED use, peripheral startup, Wi-Fi or Bluetooth association and transmission, and sleep. Measure the whole assembly rather than substituting the ESP32 chip’s datasheet figure. For example, Espressif lists 10 µA deep-sleep consumption for the ESP32 chip, but a board’s regulator, status LEDs, USB interface, external sensors, pull resistors, and other circuitry can raise assembled-system current. Espressif ESP32 Series Datasheet v5.3.
The calculation is an idealized starting point, not a runtime guarantee. Converter losses, battery cutoff voltage, temperature, cell age and condition, self-discharge, radio conditions, and voltage sag during current peaks can all reduce usable runtime. Treat rated capacity as an input to an estimate, not a promise of energy available to your circuit.
Rank #3
- Battery Specifications：Dimensions: 36*10*65mm/ 1.42*0.39*2.56inch;Battery Weight(Single): 49g; Capacity: 3000mAh; Plug: JST1.25; Discharge Rate: 1C. Make Sure Device Polarity Matches with Battery Pack Connector Before Purchase.1.Battery Size; 2.Connector Model;3.Connector Size; 4.Connector Polarity - THIS IS NOT UNIVERSAL!!! (It will cause a shortage if the polarity of the battery connector does not match your device.)
- Reliable Performance: Our 3.7 volt rechargeable lithium polymer battery provides reliable performance with long life. It is no fire, no explosion or no leakage after vibration and collision.Each lipo battery comes equipped with a built-in protection board that prevents overcharging, over-discharging, overcurrent, overheating, and short circuits. Enjoy peace of mind while using our lithium polymer battery, knowing that it is designed with advanced safety features.
- Application：Our batteries are perfect for ESP32 projects or a small Internet of Things (IoT) project. Also suitable for battery replacement of DIY 3.7V electronic products, mobile energy storage, power supply, LED light, wireless Bluetooth game headset, Bluetooth speaker, outdoor video and audio electronic scale, GPS Watch recorder, USB Fan tester, dash cam controller, gaming controller, electric toy car, mouse and keyboard, Wi-Fi smart home system, digital camera, e-book, and so on.
- Storage & Usage：When storing lithium polymer batteries for a long time, please keep the battery in a state of 40%-60%. We recommend to charge the battery every 3 months receipt of the battery and maintain the voltage 3.7-4.0V. Store battery in cool and dry place. Please contact us if you have any questions or concerns with the product via Amazon message. Storage & Usage：When storing lithium polymer batteries for a long time, please keep the battery in a state of 40%-60%. We recommend to charge the battery every 3 months receipt of the battery and maintain the voltage 3.7-4.0V. Store battery in cool and dry place.
- Easy Installation with Micro JST1.25 Connector: The 3000mAh lithium polymer battery feature a Micro JST1.25 connector and a wire of about 70mm, making installation simple and convenient. Upgrade your devices effortlessly with our user-friendly design, ensuring a secure connection for maximum performance.(NOTE!!! The maximum operating current of this battery is only about 1.5A, Can Not be used for unmanned vehicles, model aircraft or other products that require high current)
Interpret board-specific sleep figures carefully
Adafruit’s ESP32 Feather V2 guide gives rough board-specific figures of 100 mA or more for normal use, 2 mA for light sleep, and 100 µA for deep sleep, assuming external hardware is powered down. Elsewhere, the same guide gives 70 µA for that board’s deep sleep. These are vendor guide figures for the Feather V2 and its stated conditions, not universal measurements for ESP32 boards. The difference is a reason to measure your own assembled setup. Adafruit ESP32 Feather V2 guide.
Choose sleep mode for the work the device must resume
Sleep reduces power by pausing or shutting down parts of the chip, but it also changes what remains available when the device wakes. Espressif describes deep sleep this way: “In Deep-sleep mode, the CPUs, most of the RAM, and all digital peripherals that are clocked from APB_CLK are powered off.” Espressif ESP-IDF Sleep Modes documentation.
Rank #4
- Charging Method: The recommended charging current is 0.6A, the maximum does not exceed 1.5A. The discharge current is recommended 0.6A, and the maximum does not exceed 1.5A
- Overcharge Protection: When charging the battery, when the voltage reaches the highest battery voltage (4.2V), the protection board will automatically power off and shut down, indicating that it will not continue to charge when fully charged, forms overcharge protection
- Over-discharge Protection: When the battery is about to run out and the voltage is as low as 3.0V, the protection board will also be turned off and can no longer be discharged, forming an over-discharge protection effect
- Short Circuit Protection: When an accidental short circuit occurs, the protection board will automatically shut down within a few milliseconds and will not be powered on again. Note that the cell is short-circuited (not through the protection board). The protection board will also fail due to continuous high current, or the components are heated and damaged
- Widely Application: With JST 1.25 plug, these lithium polymer batteries can be used for development board whose plug is SH1.25-2, such as ESP32 LoRa V3, ESP32 LoRa V4, Wireless Tracker, Mesh Node T114, Mesh Node T096 and electronic devices
- Light sleep: Consider it when retained state or a quicker resume matters. Measure its current on your board and check which state and wake behavior your application needs.
- Deep sleep: Consider it when the device can restart work after waking and the lower-power behavior is worth the reinitialization. Plan for the code to reconnect or restore needed peripherals.
Wi-Fi and Bluetooth connections are not maintained in light or deep sleep. If the device needs network access after waking, include radio startup, association, and data transfer in both the firmware plan and current measurement. See Espressif’s sleep-mode documentation.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Reduce current during work and sleep
Limit radio-on time
If the application enables Wi-Fi or Bluetooth, stop the radio cleanly before entering sleep when the connection is no longer needed. Disable wireless features whenever the design permits, and consider batching network exchanges so the radio is active for necessary communication rather than continuously. Include the energy cost of reconnecting in your duty-cycle measurements.
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- Battery Specifications：Dimensions: 25*10*42mm/ 0.98*0.39*1.65inch;Battery Weight(Single): 19g; Capacity: 1100mAh; Plug: JST1.25; Discharge Rate: 1C. Make Sure Device Polarity Matches with Battery Pack Connector Before Purchase.1.Battery Size; 2.Connector Model;3.Connector Size; 4.Connector Polarity - THIS IS NOT UNIVERSAL!!! (It will cause a shortage if the polarity of the battery connector does not match your device.)
- Reliable Performance: Our 3.7 volt rechargeable lithium polymer battery provides reliable performance with long life. It is no fire, no explosion or no leakage after vibration and collision.Each lipo battery comes equipped with a built-in protection board that prevents overcharging, over-discharging, overcurrent, overheating, and short circuits. Enjoy peace of mind while using our lithium polymer battery, knowing that it is designed with advanced safety features.
- Application：Our batteries are perfect for ESP3 projects or a small Internet of Things (IoT) project. Also suitable for battery replacement of DIY 3.7V electronic products, mobile energy storage, power supply, LED light, wireless Bluetooth game headset, Bluetooth speaker, outdoor video and audio electronic scale, GPS Watch recorder, USB Fan tester, dash cam controller, gaming controller, electric toy car, mouse and keyboard, Wi-Fi smart home system, digital camera, e-book, and so on.
- Storage & Usage：When storing lithium polymer batteries for a long time, please keep the battery in a state of 40%-60%. We recommend to charge the battery every 3 months receipt of the battery and maintain the voltage 3.7-4.0V. Store battery in cool and dry place.
- Easy Installation with Micro PH2.0 Connector: The 1000mAh lithium polymer battery feature a Micro PH2.0 connector and a wire of about 70mm, making installation simple and convenient. Upgrade your devices effortlessly with our user-friendly design, ensuring a secure connection for maximum performance.(NOTE!!! The maximum operating current of this battery is only about 1.5A, Can Not be used for unmanned vehicles, model aircraft or other products that require high current)
Power down peripherals between tasks
Switch off or power-gate external sensors, displays, LEDs, and other loads when they are not needed between measurements. A board’s own circuitry may also draw current during sleep, so follow its low-power guidance and measure the assembled device with external elements in the states you intend to use. Adafruit’s Feather V2 guide specifically conditions its sleep figures on external hardware being powered down. Adafruit ESP32 Feather V2 guide.
Check GPIOs for unintended current paths
External circuits can draw extra current if they drive a pin against an ESP32 internal pull-up or pull-down. Review GPIO states and external pull networks for these paths; Espressif’s ESP-IDF guidance describes isolating GPIOs where appropriate. Espressif’s hardware guidance also discusses the sleep-power benefit of the ESP32 RC circuit. Confirm any changes against the exact board and circuit rather than assuming a pin setting is safe in every design. ESP-IDF sleep documentation; Espressif hardware guidance.
Measure the cycle, including peaks
- Measure battery-side current. Instrument the complete project at the battery or power input, not just the ESP32 chip. Include the sensors, conversion circuit, indicators, and other loads used in the finished design.
- Capture a representative cycle. Measure startup, active processing, radio activity, peripheral use, and sleep. Use the intended sampling and communication schedule, since a long idle reading does not represent a device that periodically transmits.
- Check transient peaks. Confirm that the battery and conversion circuit can deliver the short current bursts without the supply voltage sagging enough to cause a brownout. For ESP32-WROOM-32, Espressif’s module datasheet specifies at least 0.5 A external-supply current capability; check the requirement for your exact hardware.
- Calculate and validate. Use the measured cycle average in the capacity formula for an initial estimate, then run the device on the intended battery and observe actual operation through its discharge range.
Compare options against the actual design
| Decision | What to compare |
|---|---|
| Light sleep or deep sleep | State retention, wake source, wake latency, restart and reconnect work, and measured current. |
| Battery | Chemistry and charging requirements, voltage across discharge, capacity, physical size, and peak-current capability. |
| Power conversion | Input and regulated output ranges, peak current, quiescent current, and efficiency over the real duty cycle. |
| Integrated battery board or custom supply | Documented charger and protection, connector compatibility, regulator idle draw, LEDs or USB overhead, and measured sleep current. |
Verify advanced low-power changes on the hardware
Do not assume that powering down flash or changing an advanced sleep option will save power safely. Espressif warns that flash power-down behavior depends on hardware and timing and may require thorough verification. Test such changes on the exact board and firmware, checking both current draw and reliable wake-up before relying on them. Espressif ESP-IDF Sleep Modes documentation.
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