Panasonic Ncr21700t Datasheet Hot [cracked] Official

Has anyone else measured surface temps on these at 10A+? Would love to compare notes.

When analyzing the Panasonic NCR21700T datasheet , a few critical core figures stand out. These parameters dictate exactly how the cell operates under extreme electrical and thermal conditions: NCR21700 data sheet

The NCR21700T includes internal safety features activated by heat or pressure:

Before we talk about heat, let us look at the cold, hard numbers from the official Panasonic/Sanyo datasheet. panasonic ncr21700t datasheet hot

Due to its 5000mAh capacity and moderate (15A) discharge rating, this cell is ideal for:

At first glance, 15A continuous and 5000 mAh is excellent. But here is the catch: The datasheet says maximum 15A, but it does not say "15A without significant temperature rise." In fact, the thermal appendix of the datasheet (which most people skip) warns that operating near 15A for extended periods will push the cell surface temperature past 65°C—the official cutoff for safety.

Follow these safety rules:

✅ Flashlights (regulated), power banks, low-to-medium drain e-bikes, backup batteries. ❌ Not great for: High-drain vaping (at >15A), power tools, hotrod flashlights without thermal regulation.

It is widely cautioned that many cells sold online as "Panasonic NCR21700T" are fakes. One report warns that "the ones sold on Ali are all fake". Authentic cells from certified distributors consistently deliver their rated 5000mAh capacity, while counterfeits often fall far short. Always purchase from authorized, reputable suppliers.

Here is where most people stop reading and get into trouble. Has anyone else measured surface temps on these at 10A+

The datasheet boasts 500 cycles to 70% capacity. That is a lie if you run it hot. Look at the fine print: Cycle life tested at 0.5C (roughly 2.2A) at 25°C.

Building a battery pack with NCR21700T cells requires careful attention to their safety limits.

Heat increases resistance, which increases voltage drop. Under a 30A load, the 4.2V cell drops to 3.2V instantly. The device thinks the battery is dead (low voltage cut-off triggers), so it shuts down. You pull the battery out, it measures 3.8V, but it is scorching hot. Lower your load or use a lower-resistance cell like the Molicel P45B. These parameters dictate exactly how the cell operates