First: Download the "Data Switch" by: nfcshare (free from the market)
1.)The first thing i did was went to Settings>Wireless & Network> to make sure i'm on CDMA/LTE(4g)
2.) When I'm home I only use my WI-FI,and my Data Switch is turned off.(This will Automatically turn off the 3g/4g)
3.)Before I leave the house (for work),i will turn off my WIFI and Data Switch to off..So it means No Internet/E-mail but you can still receive text/and out going txt(if you want to txt someone), and phone calls-incoming or outgoing.
4.)@Work (No WIFI)..If i need to go on line ,i just simply turn on my Data Switch to ON (if 4g isn't available to your area,it will automatically turn to 3g)..lucky for me my place of work has a strong 4g access ..After 15min. of surfing/checking e-mails and txt. I'm gonna turn off again my DATA Switch to OFF.
TIME OBSERVATION w/ THIS PROCEDURE! From 100% (5:30 am) to 12noon(my break-time) 92% remaining.Believe this or not..it happened!