The Sony VTC6 are the preferred battery for mech mod users due to their discharge amperage.

Sony VTC6 18650 Battery Features:

• Model: USVTC6
• Manufacturer: Sony Energy
• Chemistry: IMR
• Max. continuous discharge current: 20A 
• Nominal capacity: 3000mAh
• Nominal voltage: 3.6 V
• Discharge end voltage: 2.5 V
• Charging voltage: 4.20 +/- 0.05 V
• Standard charging current: 1.5 A
• Protection: Not protected (Flat-Top)

Advice:

• Do not heat above 100℃ or 212℉.
• Battery may explode or catch fire if mistreated.
• Do not disassemble or incinerate.
• Do not expose to water or fire.
• Do not short circuit.
• Do not place loose batteries in a pocket, purse, or other receptacle containing metal objects
• Do not over-discharge/overcharge, if allowed to drop past 2.5 volts, chargers will no longer be able to charge these batteries.
• Keep away from children