If you like your eGo style and size batts but want one with considerably more functionality, I suggest the eGoV V3 Mega. Fantastic 1300mAh battery (lasts me at least two days on a charge) Battery features: press quickly 5 times to turn on/off
Voltage and wattage switch: Press the "+" button for 5 seconds to switch the mode (VV/VW)
Press the "-" button for 5 seconds to display coil resistance. It also does this automatically whenever you put one on it.
Lock the selected voltage or wattage: Press "+" and "-" buttons simultaneously for 3 seconds
Variable voltage: adjustable from 3.0-6.0V in 0.1 increments
Variable Wattage: adjustable from 3.0-15.0W in 0.5 increments
Maximum Current Output: 2.5A
Input type: DC 5V 500mA
14-seconds safety cutoff
Short-circuit and low resistance protection
0.7 inch screen shows the voltage, wattage, battery level and resistance
510/eGo threaded connector
I got this one from Fasttech and it took 3 weeks to get to me but you can probably find it somewhere that ships faster if you want to pay a little more for it. They have it in five different colors that have that non-slip slightly rubberized feel to them. I find that I use it WAY more than my heavy "steel-pipe" type mods and it does all that they do
plus has passthrough and is a fraction of their size or weight! Hard to beat all that for $23.91 w/free shipping!!
https://www.fasttech.com/products/0/10007241/1670704-ego-v-v3-mega-evod-1300mah-vv-vw-starter-kit