VapCell G45 21700 4500mAh 20A Batteries

Batteries in the actively promoted 21700 form factor, designed for a continuous discharge current of 20 A and rated at 4500 mAh.

This model caught my interest because it offers a decent discharge current while its 4500 mAh capacity is close to the maximum for this size. At least, I haven't come across anything above 5000 mAh, and it's unlikely such cells exist.

The model on the manufacturer's website: link.
AliExpress listing: link, priced at $13.18 for 1 cell and $17.59 for 2. There are also listings for other quantities and models with a protruding positive terminal.

Key specifications
Model: INR21700 4500mah 20A
Size: 21.6*71.0mm
Nominal voltage: 3.60V
End-of-charge voltage: 4.20V
End-of-discharge Voltage: 2.5V
Typical Capacity: 4500mAh (0.2C discharge)
Min capacity: 4400mAh (0.2C discharge)
Weight: Max:70g
Internal resistance: Max:16mΩ （AC 1kHz）
Standard Charge: 1500mA,CCCV 100mA cut-off
Quick Charge Current: 3000mA
Max Continuous Discharge Current: 20A

Unlike the batteries shown previously, these came in branded packaging. I can't say whether it's included with the ones at the link above (I can check if needed), but it looks pretty good.
The case is sturdy, with a link to the VapCell website on the bottom. The batteries don't rattle around inside.


In appearance, these batteries look very much like Molicel products. However, the Molicel model I tested had a capacity of 4200 mAh, while the Basen cell rated at 4000 mAh looks even more like the ones under review.


The dimensions and weight match the specifications. Note that the 21.7 mm diameter is partly due to the label; without it, the diameter is about 0.2 mm smaller.


The "conditioning" cycle yielded a capacity of about 4900 mAh, partly because a 0.5 A discharge current is close to 0.1C for batteries like these.


According to the specifications, the standard charging current is 1.5 A and the fast-charge current is 3 A. I charged them at 2.25 A during the tests, which is 0.5C; charging took 2 hours and 22 minutes.


Nice—the battery delivered more than its rated capacity: 4580 mAh, or 16.76 Wh, at a 0.2C current.


Temperature at 10, 15, and 20 A. At the maximum current, you could call it high, but branded batteries can get much hotter and that's considered normal, so in my opinion, these results are excellent.


The second battery fell a little short, but still delivered 4522 mAh, which also meets the stated specifications.


Its temperature was about the same as the first battery's.


No complaints about the internal resistance either: it's rated at 16 mΩ, and measures about 14.
Before testing, after "conditioning," and the final reading.


The results exceed the manufacturer's specifications, which doesn't happen very often. However, it's worth remembering that these are batteries in the so-called "mid-range" class in terms of discharge performance. For example, there are 4000 mAh models rated for currents up to 40 A.
Even so, these batteries may be suitable for powerful flashlights and e-cigarettes, since they can deliver up to 70 W continuously.