Using your cobalt mine mobile phone in G or Dual Mode drains the battery much quicker than just GSM mode. Somewhere in the manual for your phone will be listed the battery times separately for GSM and 3G. On modern mobile phones, the GSM only life-cycle can be up to 50% more efficient.
I recently submitted an article to Smartphone and Pocket PC magazine on some of the tools I recommend for mobile productivity. I mentioned a portable scanner and printer Lithium mines Ontario that I try to avoid toting unless I know for certain I will need them. That was before CES and my discovery of an incredible pair of products from PlanOn with its DocuPen and petite printer.
The mating process between the two engines can be in series or in parallel. When the two powertrains are mated in series, only one of the motors controls the cars movement. The other one simply assists the first, dominant engine. This occurs most often in mild or assist hybrids. The Saturn Vue Green Line Belt Alternator System (BAS) is a good example. The concept vehicle named the Volt from GM is another good example of a series (but not a mild) hybrid.
This cordless driver comparison showed that Lithium-ion batteries hold a charge a lot longer than a nicad battery. A fully charged Lithium-ion batteries can hold a charge for up to a year. My cordless driver comparison did clarify to me that when comparing drivers its important to compare cordless drivers with similar power. Power wise a 12 volt Nicad battery has the same power as a 12 volt Lithium battery stocks ion battery and a 18 volt nicad battery has the same power as a 18 volt Li-ion battery. So don't expect the same torque found in a 18 volt nicad cordless drver from a new 12 volt li-ion cordless driver.
When you store it, make sure the temperature is not too high nor too low. Don't freeze it and storing the unit in a hot car or near the radiator is a bad idea as well. Use a sealable bag, charge the battery to about 50% and put it into the fridge between 0 and 5C.
Battery chargers for mobile phones are notable in that they come in a wide variety of connector-styles and voltages, most of which are not compatible with other manufactures' phones or even different models of phones from a single manufacturer.