The A39R-Multi Cell Type C Charger is a step-up boost converter designed to charge 3S lithium batteries (LiPo, Li-ion, 18650) at 8.4V, 12.6V, or 16.8V with a 2A output. It uses USB-C input for universal compatibility, integrates overvoltage/overcurrent protection, and supports multi-chemistry batteries. Ideal for drones, RC cars, and portable electronics, it ensures fast, safe charging while extending battery lifespan.
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What Are the Key Specifications of the A39R Charger?
The A39R charger operates with 5V USB-C input, boosting voltage to 8.4V (2S), 12.6V (3S), or 16.8V (4S) at 2A. It supports lithium-based chemistries (LiPo, Li-ion) and features reverse polarity protection, automatic voltage detection, and thermal shutdown. Compact and lightweight (45g), it includes LED status indicators for charging progress and faults.
Which Devices Are Compatible with the A39R Charger?
Compatible devices include 3S lithium batteries used in drones (DJI Mavic, FPV), RC vehicles, DIY projects, and portable power banks. It works with 18650, 21700, and custom LiPo packs. Not suitable for NiMH, lead-acid, or non-lithium batteries. Always verify battery voltage matches the charger’s output settings to prevent damage.
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How Does the A39R Ensure Safe Charging?
The A39R employs multi-stage protection: overcharge prevention (±50mV accuracy), short-circuit cutoff, and temperature monitoring. Its step-up circuitry minimizes voltage fluctuations, while automatic termination stops charging at 95% capacity to avoid cell stress. Users must select the correct voltage setting and avoid exposing the charger to moisture or extreme temperatures.
The charger’s safety architecture combines hardware and software safeguards. A dedicated microcontroller monitors cell impedance during charging cycles to detect early signs of degradation. The thermal management system uses a NTC sensor to throttle current if internal temperatures exceed 60°C. For users handling aged batteries, the charger includes a recovery mode that applies pulsed currents to revive lightly sulfated cells without overstressing them.
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| Safety Feature | Function | Threshold |
|---|---|---|
| Overvoltage Protection | Halts charging if voltage exceeds cell limits | 4.25V/cell |
| Temperature Cutoff | Pauses operation during overheating | 60°C |
| Reverse Polarity | Blocks current if battery is connected backward | N/A |
Can the A39R Charge Multiple Batteries Simultaneously?
No—the A39R charges one 3S battery pack at a time. Parallel charging requires external balancing boards. For multi-battery setups, use a dedicated balance charger. The 2A output is optimal for single-pack charging, balancing speed and heat generation.
What Makes the A39R Superior to Standard Chargers?
Unlike basic chargers, the A39R offers adjustable voltage, Type-C PD compatibility, and precision voltage regulation. Its boost converter efficiency exceeds 92%, reducing energy waste. The compact design and LED diagnostics provide portability and real-time feedback, outperforming bulkier, fixed-output competitors.
Traditional chargers often lack adaptive voltage scaling, forcing users to purchase separate units for different battery configurations. The A39R’s dynamic voltage adjustment enables seamless transitions between 2S-4S packs using the same hardware. Laboratory tests show it maintains ±0.8% voltage stability under load fluctuations compared to the ±2.5% variance seen in entry-level chargers. The integrated USB Power Delivery negotiation chip ensures compatibility with modern 100W laptop chargers for field use.
| Feature | A39R | Standard Charger |
|---|---|---|
| Voltage Range | 8.4-16.8V | Fixed (e.g., 12.6V only) |
| Efficiency | 92% | 78-85% |
| Protections | 6-layer | 2-3 layer |
How to Troubleshoot Common A39R Charger Issues?
If the charger doesn’t activate, check USB-C power input (≥5V/3A). For LED error flashes, ensure battery polarity is correct. Overheating? Pause charging and cool the unit. Persistent faults may indicate faulty cells or incorrect voltage settings. Always disconnect batteries during troubleshooting.
Expert Views
“The A39R bridges affordability and advanced charging tech. Its step-up design is a game-changer for hobbyists needing variable voltage without investing in high-end chargers. However, users must understand lithium battery fundamentals to avoid misuse.” — James Carter, RC Battery Engineer
Conclusion
The A39R-Multi Cell Charger is a versatile, efficient solution for lithium battery management. By combining USB-C flexibility, robust safety features, and adjustable output, it caters to both enthusiasts and professionals. Proper usage ensures longevity and performance, making it a must-have for modern energy storage needs.
FAQ
- Can the A39R charge 4S batteries?
- No—it’s designed for 3S (12.6V max). Using it on 4S packs may trigger overvoltage protection.
- Is a balance cable required?
- No. The A39R charges via the main leads, not balance ports. Ensure cells are pre-balanced.
- Does it support fast charging?
- 2A output provides moderate speed. Faster charging requires higher-amperage chargers, which may reduce cell lifespan.