1. Introduction
This user manual provides essential information for the safe and effective use of your Molicel P42A 4200 mAh 45A rechargeable battery. Please read this manual thoroughly before using the product to ensure proper operation and to prevent potential hazards. This battery is designed for high-current applications and requires careful handling.
2. Safety Information
Your safety is paramount. Please adhere to the following warnings and guidelines to prevent injury, damage, or fire.
Important Warnings:
- Short Circuit Prevention: Always keep the battery in its protective case when not in use to avoid short circuits.
- Proper Storage: Do not store your battery in a pocket, purse, or with any metal items (e.g., keys, coins) to prevent accidental short circuits.
- Unprotected Battery: This battery is unprotected. It is the user's responsibility to ensure it is not over-discharged.
- Discharge Limits: Discharge to no lower than 2.5V (3V recommended).
- Maximum Discharge: The maximum continuous discharge current is 20 Amps. Exceeding this can lead to overheating and damage.
- Temperature: Do not expose the battery to extreme temperatures (hot or cold).
- Physical Damage: Do not puncture, deform, or disassemble the battery. If the battery casing is damaged, discontinue use immediately.
- Disposal: Dispose of batteries responsibly according to local regulations. Do not dispose of in general waste.

Image: A single Molicel P42A battery, illustrating its cylindrical shape and positive/negative terminals. Always handle with care to prevent short circuits.
3. Product Overview
The Molicel P42A is a high-performance, flat-top rechargeable battery designed for applications requiring high current output. Its 21700 size and 4200 mAh capacity make it suitable for various electronic devices.
Key Features:
- High Capacity: 4200 mAh for extended use.
- High Discharge Rate: Capable of high current output (up to 45A pulse, 20A continuous).
- Flat Top Design: Compatible with devices requiring flat-top batteries.
- Class A Battery: Ensures quality and reliability.

Image: A Molicel P42A battery highlighting its 4200 mAh capacity and 45A Continuous Discharge Rating (CDR).
4. Setup
4.1 Initial Inspection
- Upon receiving your battery, carefully inspect it for any signs of physical damage, such as dents, punctures, or swelling. Do not use if damaged.
- Check the battery's voltage with a multimeter if possible. A healthy battery should have a voltage above 2.5V.
4.2 First Use and Charging
- Before first use, it is recommended to fully charge the battery using a compatible external battery charger designed for 21700 lithium-ion batteries.
- Ensure the charger's voltage and current settings are appropriate for the Molicel P42A. Overcharging can damage the battery and pose a safety risk.
- Always charge batteries on a non-flammable surface and never leave charging batteries unattended.
5. Operating Instructions
5.1 Battery Installation
- Identify the positive (+) and negative (-) terminals on both the battery and your device.
- Insert the battery into your device, ensuring correct polarity. Incorrect installation can damage both the battery and the device.
- Ensure the battery fits snugly within the device's battery compartment.
5.2 Usage Guidelines
- Use the battery only with devices that are compatible with 21700 size and can handle the battery's discharge specifications.
- Monitor the battery's performance during use. If you notice excessive heat, unusual odors, or changes in performance, discontinue use immediately.
- Avoid fully discharging the battery below 2.5V to prolong its lifespan. Recharge when the device indicates low battery.
6. Maintenance
6.1 Cleaning
- Keep the battery terminals clean and free from dirt or corrosion. Use a dry, soft cloth to wipe them if necessary.
- Do not use water or liquid cleaners on the battery.
6.2 Storage
- Store batteries in a cool, dry place, away from direct sunlight and extreme temperatures.
- For long-term storage, charge the battery to approximately 3.7V - 3.8V (around 50% charge) to maintain its health.
- Always store batteries in a non-conductive, protective case or sleeve to prevent accidental short circuits.

Image: Two Molicel P42A batteries, demonstrating proper storage in individual protective sleeves to prevent contact and short circuits.
7. Troubleshooting
If you encounter issues with your Molicel P42A battery, refer to the table below for common problems and solutions.
| Problem | Possible Cause | Solution |
|---|---|---|
| Battery not charging | Faulty charger; dirty terminals; battery fully discharged; damaged battery. | Try a different charger; clean battery and charger terminals; if battery is below 2.5V, it may be unrecoverable; discontinue use if damaged. |
| Battery not powering device | Incorrect installation; low charge; incompatible device; damaged battery. | Check polarity and ensure proper seating; recharge battery; verify device compatibility; discontinue use if damaged. |
| Battery overheating during use/charging | Over-discharge; short circuit; faulty device/charger; internal battery issue. | Immediately discontinue use and remove from device/charger; allow to cool in a safe area; do not use if overheating persists. Dispose of safely. |
| Reduced battery life | Aging battery; frequent deep discharges; improper charging/storage. | Battery capacity naturally degrades over time; avoid deep discharges; follow recommended charging and storage practices. |
8. Technical Specifications
| Specification | Value |
|---|---|
| Model | P42A |
| Brand | VOOPOO (Molicel) |
| Battery Type | Rechargeable Lithium Polymer (LiPo) |
| Capacity | 4200 mAh |
| Nominal Voltage | 3.6V - 3.7V (typical) |
| Maximum Continuous Discharge Current | 20A (as per product description) |
| Maximum Pulse Discharge Current | 45A |
| Minimum Discharge Voltage | 2.5V (3V recommended) |
| Size | 21700 (21mm diameter, 70mm length) |
| Top Style | Flat Top |
| Manufacturer Reference | MOP42A |
| Country of Origin | China |
9. Warranty Information
This product is covered by the standard manufacturer's warranty against defects in materials and workmanship. Please refer to the retailer's or manufacturer's website for specific warranty terms and conditions. The warranty typically covers manufacturing defects but does not cover damage caused by misuse, improper handling, or unauthorized modifications.
10. Customer Support
For further assistance, technical support, or inquiries regarding your Molicel P42A battery, please contact the retailer from whom you purchased the product or visit the official VOOPOO website for support resources.
Always provide your product model (P42A) and any relevant purchase information when seeking support.





