LiPo Battery Capacity Indicator 1S–7S | 5-LED Voltage Tester
LiPo Battery Capacity Indicator 1S–7S | 5-LED Voltage Tester
Instantly Check Your Battery Level with 5 LED Indicators
Never be caught off guard by a dead battery again. The LOTHYE LiPo Lithium Battery Capacity Indicator gives you an instant, clear readout of your battery's charge level across a wide range of lithium battery configurations — from 1S single cells all the way up to 7S packs. With its ultra-slim profile and intuitive 5-LED display, this compact tester is a must-have for RC hobbyists, drone pilots, engineers, and anyone working with lithium, lead-acid, or lithium iron phosphate batteries.
Made in Mainland China.
Why You'll Love This Battery Tester
- Wide Compatibility: Works with 1S to 7S lithium battery packs (3.7V–29.4V), as well as lead-acid, lithium iron phosphate, and electric vehicle batteries.
- 5-LED Power Display: Ultra-thin design with 5 LEDs showing charge status in four clear stages — 25%, 50%, 75%, and 100% — at a glance.
- Reverse Connection Protection: Built-in safeguard means accidental positive/negative reversal won't damage the module — just reconnect correctly and go.
- Zero Standby Drain: Press the button to activate the display; LEDs auto-off after 3–10 seconds and draw zero power at rest.
- Durable & Lightweight: Made from high-quality materials. Weighs just 8g with a slim 40 × 15 × 2.5mm footprint — easy to install in any build.
- ±2% Accuracy: Reliable readings with a tight 2% allowable error range for day-to-day monitoring needs.
Technical Specifications
| Supported Configurations | 1S / 2S / 3S / 4S / 5S / 6S / 7S |
| Voltage Range | 3.7V – 29.4V |
| Allowable Error | ±2% |
| Display Stages | 25% / 50% / 75% / 100% |
| Working Current | 15mA |
| Lead Length | 15cm |
| Dimensions | 40 × 15 × 2.5mm |
| Net Weight | 8g |
| Working Temperature | -10°C to 65°C |
| Origin | Mainland China |
Battery Configuration Reference Chart
- 1S: 3.7V nominal — 4.2V fully charged
- 2S: 7.4V nominal — 8.4V fully charged
- 3S: 11.1V nominal — 12.6V fully charged
- 4S: 14.8V nominal — 16.8V fully charged
- 5S: 18.5V nominal — 21.0V fully charged
- 6S: 22.2V nominal — 25.2V fully charged
- 7S: 25.9V nominal — 29.4V fully charged
LED Indicator Logic
- 1st LED (Red): Power indicator — always on when button is pressed
- 2nd LED (Blue): On when voltage > N × 3.3V
- 3rd LED (Blue): On when voltage > N × 3.5V
- 4th LED (Blue): On when voltage > N × 3.7V
- 5th LED (Blue): On when voltage > N × 3.9V
- Note: 3.7V single-cell (1S) variant uses green LEDs; all other voltage ranges use blue LEDs.
How to Use
- Connect the indicator's positive and negative leads to the corresponding terminals on your battery.
- Press the red button lightly — the LED display will illuminate, showing real-time charge level.
- Release the button. The LEDs will auto-shut off after 3–10 seconds, consuming zero standby power.
- If wires are accidentally reversed, the reverse-protection circuit keeps the module safe — simply reconnect correctly.
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Learn more: ENERGY STAR product efficiency guidance
Frequently Asked Questions
Q: Which battery types are compatible with this LiPo battery capacity indicator?
A: This indicator is compatible with lithium (LiPo/Li-ion) batteries from 1S to 7S (3.7V to 29.4V), as well as lead-acid batteries, lithium iron phosphate (LiFePO4) packs, and electric vehicle battery systems. It is not suitable for applications requiring greater than ±2% accuracy.
Q: Will connecting the wires backwards damage the battery tester?
A: No. The module features built-in reverse connection protection. If the positive and negative leads are accidentally swapped, the circuit will not be damaged. Simply reconnect the wires in the correct orientation and the indicator will function normally.
Q: Does the indicator drain the battery when not in use?
A: No — this indicator draws zero power in standby mode. The LEDs only activate when you press the button, and automatically switch off after a 3–10 second delay once the button is released, making it ideal for permanent installation in battery-powered builds.
Q: How do I read the charge level from the LED display?
A: The 5-LED display shows battery charge in four stages: approximately 25%, 50%, 75%, and 100%. The first (red) LED is the power indicator. Each additional blue (or green for 1S) LED that illuminates represents a higher charge level, based on the cell voltage thresholds for your specific battery configuration (N × 3.3V, 3.5V, 3.7V, and 3.9V per cell).