3S 12V Lithium Battery 5-LED Level Indicator Module with Push Button is an ultra-slim, zero-standby-drain 5-stage LED battery fuel gauge strip designed for 3S (11.1V/12.6V) lithium-ion and LiPo battery packs. Equipped with an onboard momentary push-button switch, reverse-polarity protection, and 140mm pre-soldered wire leads, it illuminates 1 to 5 indicator LEDs to show exact remaining charge whenever the button is pressed, and turns completely OFF with zero standby current draw when released.
Key Features:
- 5-Segment LED Battery Fuel Gauge: Displays battery charge state across 5 discrete LED steps (20%, 40%, 60%, 80%, 100%) for higher resolution than 3-LED or 4-LED indicators.
- Push-to-Test Zero Standby Drain: Only draws ~30mA while you press the red tactile button; releasing the button cuts off the indicator circuit completely so 0mA is consumed during storage!
- Built-In Reverse-Polarity Protection: Series protection diode prevents board damage if the positive and negative test leads are accidentally reversed.
- Pre-Soldered 140mm Wire Leads: Ready to solder or crimp directly across your battery pack `B+`/`B-` or `P+`/`P-` terminals out of the bag.
- Ultra-Thin Strip Profile: Slim PCB mounts cleanly on the outside of heat-shrink battery packs, power tool cases, or DIY project panels.
Technical Specifications:
- Supported Battery Pack: 3S 11.1V / 12.6V Li-ion / LiPo Battery Pack (12V Lithium Systems)
- Display Resolution: 5 × SMD Indicator LEDs (5 Voltage Steps + 1 Power Indicator)
- Active Test Current: ~30 mA (Only while Button is Pressed)
- Standby Quiescent Current: 0 µA (Completely Disconnected when Button is Released)
- Reverse Polarity Protection: Yes
- Pre-Attached Wire Length: ~140 mm
Mechanical Specifications:
- PCB Material: Slim FR-4 Fiberglass Strip PCB
- Controls: 1 × Onboard Red Momentary Tactile Push Button
- Leads: Red (+) and Black (-) 140mm Insulated Wire Leads
Dimensions:
- PCB Length: ~40 mm
- PCB Width: ~10 mm to 12 mm
- Thickness: ~3.5 mm
- Weight: ~4 g
Pinout and Wiring:
- Red Wire (+): Connect to 3S (12V) battery pack positive terminal (`B+` or `P+`).
- Black Wire (-): Connect to 3S (12V) battery pack negative terminal (`B-` or `P-`).
- Operation: Press the red button with your finger during charging or discharging to view the 5-level LED bar graph; release to turn off.
Datasheet Reference:
- Circuit Architecture: Multi-Stage Precision Resistor Ladder + Comparator/Transistor LED Bar Driver with Momentary Switch
Commonly Used in:
- 3S 11.1V / 12.6V 18650 DIY Battery Packs & Solar Generators
- 12V Cordless Drill, Sprayer, and Searchlight Battery Housings
- RC Transmitter & FPV Ground-Station 3S LiPo Packs
- 12V Inverter & Router UPS Backup Packs
Applications:
- Embeds under clear PVC heat-shrink wrap on custom 3S 18650 battery packs so you can press through the wrap to check remaining charge at any time.
- Eliminates the constant 15mA–20mA parasitic battery drain of always-on LED voltmeters and bar graphs.
- Provides instant visual confirmation during both charging and discharging.
Equivalent Models:
- XD-82B 12V 4-LED Battery Level Capacity Indicator Module: LM339 4-LED (Red/Yellow/Green) 12V battery indicator board.
- 4S 16.8V BMS Li-ion Battery Lithium Battery Capacity Indicator: Panel-mount 4-bar LED battery indicator for 4S (14.8V/16.8V) packs.
Package Includes:
- 1 × 3S 12V Lithium Battery 5-LED Level Indicator Module with Push Button
