Samsung 35E 18650 Battery 3500mAh 8A - Button Top (4-Pack) - Free Shipping

Key Features

• Genuine Samsung Core + Professional Button Top: Each cell starts as an authentic INR18650-35E flat top. We equip it with a sturdy, low-resistance button top welded using industry-leading techniques for maximum durability and performance.

• Massive 3500mAh Capacity: Typical capacity of 3500mAh (3350mAh min) means dramatically extended runtime in flashlights, headlamps, vaporizers, and portable electronics.

• 8A Continuous Discharge Rate: Safely delivers up to 8A continuous (13A pulse), perfectly suiting regulated mods with builds above 0.5 ohms, high-output LED torches, and power tools with moderate current demand.

• Universal Button Top Compatibility: Works right out of the box in devices with physical reverse-polarity protection, recessed positive contacts, and dual-spring battery tubes. Say goodbye to unreliable magnet spacers.

• Ultra-Low Added Resistance: The welded button top raises internal resistance by under 2mΩ, keeping total IR ≤25mΩ. Expect no additional voltage sag or heating compared to a native flat top.

• Long Cycle Life & Value: ≥500 charge/discharge cycles (to 70% capacity) under standard conditions, lowering total cost of ownership and replacement frequency.

• Unprotected Cell for Flexibility: No built-in protection PCB means you can integrate a custom BMS for pack building or use the cells directly in devices that already have low-voltage cutoff and overcurrent safeguards.

• No Memory Effect & Easy Maintenance: Charge anytime without full discharge; Li-ion chemistry stays efficient and ready.

• Free Shipping & Secure Packaging: The 4-pack ships free with protective individual cell separation, making it an affordable, risk-free addition to your battery stock.

• Retained Native Safety Features: Despite the welded cap, the cell’s internal CID, PTC, and vent mechanism remain fully functional and unaltered.

This is button‑top | Need flat‑top? Click here

Parameters

Applications

• High-Performance Flashlights & Searchlights: Specifically for brands and models that demand button top cells due to physical reverse-polarity rings or recessed springs, such as Surefire, Fenix, Nitecore, and Olight. Enjoy stable, high-mode output without flickering.

• Medical & Industrial Handhelds: Portable infusion pumps, patient monitors, handheld data terminals, and RFID scanners frequently employ button-top-positive battery bays. These cells are a drop-in solution for continuous, reliable operation.

• Wireless & Digital Devices: Use in wireless security cameras, digital audio recorders, portable scanners, and upgraded RC transmitter packs (Futaba/JR-style) where the battery tray is designed for a raised positive terminal.

• Toys & STEM Kits: Many motorized toy and educational robot kits require button top 18650s for proper contact. The 4-pack keeps the fun running and provides spares for high-drain sessions.

• Solar & Camping Lights: Outdoor lanterns, solar path lights, and tent lamps often utilize 2S tray holders that rely on button tops for series connection. Long cycle life means seasons of maintenance-free operation.

• User-Serviceable Power Bank Enclosures: Certain DIY power bank cases only recognize batteries with a button top. Build a compact 14,000mAh portable charger by dropping these four cells in parallel.

• Emergency & Backup Power: Pre-build swappable battery cartridges with button top contacts for emergency lights or portable power stations. High energy density ensures long standby and runtime.

Pack Building Caution: If you intend to spot-weld these cells into a multi-cell battery pack, the protruding button top prevents the positive terminal from sitting flush with nickel strips, increasing the risk of bad welds or shorts. For pack assembly, we strongly recommend using our flat top version. Series connections must include a balancing BMS. Never solder directly onto cells.

FAQ

1. Does this battery have a protection circuit? Is it just a button top on an unprotected cell?
Correct, it is an unprotected cell with a button top. There is no internal PCB that limits current or provides overcharge/over-discharge protection. The button top is purely a physical positive terminal extension. The cell measures approximately 66.5mm in length, significantly shorter than typical protected button top cells (70mm+), fitting standard bays.

2. Does Samsung manufacture the 35E as a button top originally? How is this made?
Samsung SDI only produces the 35E in a flat top configuration. Our button top version is crafted by taking genuine Samsung flat top cells and welding a precision cap in a clean, controlled setting. We use solid-state bonding (ultrasonic or resistance welding)—absolutely no solder or conductive epoxy.

3. Will the welded button top increase internal resistance or affect performance?
Our process adds negligible resistance (typically <2mΩ). The total IR of the finished cell remains well within the ≤25mΩ specification, and the 8A continuous discharge capability is unchanged. You will experience the same voltage response as the original flat top.

4. Why should I choose the button top version over flat top?
If your device’s positive contact is recessed inside a physical reverse-polarity guard, or if it uses a flat spring but the terminal must protrude to reach, a flat top may not work at all. A button top makes a reliable, direct electrical connection without needing dangerous little magnets that can slip and short-circuit.

5. Will it fit all my 18650 devices?
The button top increases the cell height to around 66.5mm. It fits most devices designed to accept protected 18650s (up to 70mm). However, if your device has an extremely tight battery compartment and previously accepted a flat top with zero extra room, it might be too long. Please measure your battery cavity or consult your device manual.

6. Can I spot-weld or solder to the button top for pack building?
We do not recommend it. The raised top makes it difficult to achieve a flat contact for nickel strips, and heat from soldering or misaligned welding probes can damage the cell. For pack construction, please order the flat top version instead.

7. What charger is compatible with button top cells? Do I need a special charger?
Any standard, high-quality Li-ion charger (XTAR, Nitecore, Opus, Efest, etc.) with sliding negative contacts will accommodate button top cells without issue. The positive contact easily reaches the raised terminal. Always use a charger with reliable 4.2V termination.

8. Are the 4 cells matched in capacity and IR?
They are sourced from the same production batch and have consistent voltage, but this product does not include precision matching. If you require tightly matched sets for series battery building, please contact us for a custom matching quote. A balancing BMS is still strongly recommended.

9. How can I verify these are authentic Samsung cells underneath the cap?
The base flat top cell features all genuine Samsung hallmarks: crisp heat-shrink printing, a distinct embossed ring on the positive cap edge, and a raised, grey laser-etched code. Our button top cap is cleanly welded with a polished finish. We guarantee authenticity and offer a full refund if proven counterfeit.

10. Should I charge them upon arrival? How about storage?
They arrive at about 3.6V—the ideal storage voltage. You can use them immediately or store them as is. For long-term storage, keep them in a cool, dry place, and every 6–12 months check the voltage and recharge to 3.6–3.7V if needed.

11. Can I take these batteries on a flight?
Each 35E is approximately 12.6Wh, for a total of about 50.4Wh across the 4-pack. This falls within the typical IATA carry-on allowance (under 100Wh). Always place each cell in an individual insulator (plastic case or tape over terminals) to prevent shorts. Check with your specific airline for any additional restrictions.

12. How does free shipping work? What are the delivery times?
Free standard shipping is automatically applied to this 4-pack. Orders are processed within 1–3 business days, and transit times typically range from 5–10 business days depending on your destination. You will receive a confirmation with tracking information once the order ships.