I currently have two batteries. I have a standard battery and an extended battery ( which I use on a regular basis ). My question is if I charge the extended battery, put it into my desk or whatever, and use my stock battery...will the charged extended battery keep it's chrge until I need it? I like the extended battery, as it has a 2-3 day battery life, but is quite weighty. The stock battery is a day, tops. I could deal with that while at work or home, but when travelling I would need the extended battery. Sooo..if I charged the extended then put it away, will it keep its charge for a while? Also, would it freak out the phone changing batteries with different charges?