you don’t have to worry about battery shipping restrictions unfairly impacting small-scale producers when you can ask your recipient to go to a vape shop and buy a 18650 for a modest markup.

Also: The best power banks you can buy: Expert tested I took a closer look at the batteries. They were all no-name 18650 lithium ion cells, and I measured the capacity to be about 2,000 mAh.

One of the common types of li-ion batteries that’s in use is the 18650 cell. These cells are cylindrical in shape and are 18 mm (0.71 inches) in diameter and 65 mm (2.56 inches) long.

At 900 cycles, 18650 batteries made with Novacium’s GEN3 silicon-based anode materials are still delivering more than 3,100 milliampere-hours (mAh) of capacity retaining more than 80% ...