IMR 18650 3.7V 1200mAh Lithium-Ion Battery (4.44Wh) - Flat Top

FREQUENTLY ASKED QUESTIONS (FAQ)

1. What does "18650" actually mean? It is the physical size code. "18" means it is 18mm in diameter. "65" means it is 65mm long. The "0" indicates it is a cylindrical cell.

2. What does IMR stand for? IMR stands for Lithium Manganese Rechargeable. It is a specific type of lithium-ion chemistry known for being safer and allowing for better current discharge than older chemistries.

3. Is this a flat top or button top battery? This is a flat top battery. The positive terminal does not protrude.

4. Does this battery have a built-in protection board (BMS)? No. This is an "unprotected" raw cell. You must use an external BMS board or a device with built-in low-voltage cutoff to prevent over-discharging it.

5. Can I solder wires directly to the top and bottom of this battery? NO. Applying the high heat of a soldering iron directly to the steel casing will damage the internal chemistry and can cause the battery to explode. You must use a dedicated battery spot-welder, or simply place it in a spring-loaded 18650 battery holder.

6. What is the nominal voltage? The nominal (average operating) voltage is 3.7V.

7. What is the voltage when it is fully charged? A fully charged 18650 reads exactly 4.2V on a multimeter.

8. How low can I safely drain this battery? You should never let an unprotected 18650 drop below 2.8V to 3.0V. Draining it below this will cause permanent chemical damage, and it may refuse to recharge.

9. What does "discharge at 0.2C" mean? "C" is the total capacity. 0.2C means 20% of 1200mAh, which is 240mA. Drawing roughly 240mA continuously is the optimal testing rate to get exactly 1200mAh of runtime out of the cell.

10. Can my project draw more than 240mA? Yes. 18650 cells can handle high currents (often several amps). However, running it under a heavy, continuous load means the voltage will sag faster, and you may extract slightly less total capacity than the 1200mAh rating.

11. How do I charge this? You must use a dedicated 18650 lithium-ion charger cradle, or an integrated charging circuit module like the TP4056.

12. Can I wire two of these together to get 7.4V? Yes. Placing two cells end-to-end (in series) gives you 7.4V. However, you must wire them through a 2S BMS protection board to ensure they charge and discharge safely.

13. Can I wire two together to get 2400mAh? Yes. Wiring them side-by-side (positive to positive, negative to negative) creates a parallel pack, keeping the voltage at 3.7V but doubling the capacity to 2400mAh.

14. Can I mix this 1200mAh battery with a 2600mAh battery in a pack? Absolutely not. Never mix batteries of different capacities, different brands, or different ages in the same series or parallel circuit. The weaker battery will be destroyed and could catch fire.

15. What is the plastic ring on the top for? The white ring is an insulator. It prevents the positive center terminal from short-circuiting against the outer edge of the top, which is connected to the negative casing.

16. What should I do if the purple plastic wrapper tears? The entire metal cylinder under the wrapper is the negative terminal. If the wrapper tears, the battery can easily short-circuit against a metal enclosure. Stop using it immediately and re-wrap it using custom 18650 PVC heat shrink tubing.

17. Is this battery waterproof? No.

18. Can I use this in my vape/e-cigarette? Vapes draw massive, momentary spikes of current. Because the exact maximum continuous discharge (Max A) rating is not specified for this generic 1200mAh cell, it is not recommended for high-drain vape devices. Stick to specialized, high-drain brand-name cells for vaping.

19. Why does the picture show a purple battery, but mine is green/blue? Battery manufacturers frequently change their PVC wrapper colors depending on the production batch. The color does not affect performance.

20. How should I store this battery if I am not using it for months? Do not store it at 100% (4.2V) or 0% (dead). Store it in a cool, dry place at a "storage charge" of roughly 3.7V to 3.8V to prolong its overall lifespan.