This is the same Aspire K3 battery that comes with the K3 starter kit. It can be used with other tanks that are about 18mm (same diameter) but do not use with low/sub-Ohm coils. That means no coils that have a resistance of less than 1.2Ω.
The K3 battery operates at a fixed 5.5V, which is approximately 16W using a 1.8Ω coil and approximately 18W using a 1.6Ω coil.
Battery capacity is 1200mAh
Manual battery turned on/off with a 5 click function