Following is a question asked by one of forum friends,i quotated here and hope answer this question will help those users who have the same problem

"I have an istick 30w with my Aspire Atlantis and love the vapor production of the Atlantis, but am not thrilled with the battery life of the istick. I'm looking for a safe, regulated box mod with a digital display that will last me at least the entirety of the day. I've been looking at the Sigelei 100w, IPV3, and the istick 50w. USB charging is a plus, but I'm willing to throw down the extra money for batteries if I can have consistent extended battery life. Any suggestions? "

And following is my answer

Well if you are in the market for a long battery life, and Sigelei is your favorite, then you can give Sigelei 100w a shot, it can meet all your requirement and following are more details about Sigelei 100w box mod



Features

510 threading
Copper contacts
OLED Screen
Runs 2pcs 18650 Battery(batteries sold separately)
10-100W wattage output: 10-50W in 0.1W increments, 50-100W in 1W increments
Lowest atomizer resistance: 0.15ohm
Battery voltage operating range: 6.4-8.4V
Features a 5 click On/Off switch
0.66" OLED display: resistance, voltage/wattage, battery level
Lock/unlock function: when system is locked, the device doesn't work
Low resistance warning (< 0.15ohm)
Low battery warning (input voltage < 6.4V)
Over voltage warning (high battery input voltage: > 9V)
Over heat warning

Sigelei 100W Specification

Material: Aluminum alloy
Battery: 18650
Battery Capacity: 1801mAh -2500 mAh
Chip: 100watt new chip
Output wattage: 7 Watts – 100 Watts
Output Voltage: 1.0 Volts – 7.0 Volts
Output Current: 30.0 A
Input Voltage: 3.0 Volts – 9.0 Volts
Input Current: 1.3 A – 20.0 A
Atomizer Resistance: ~0.1Ω-2.0Ω
Optimal voltage range 3.0v-8.5
Screen On Current: 25 mA
Quiescent Current: 1 mA
Power Down Current: 350 uA
Dimension: 96*52*33 mm
Color: Silver/Black