1. Field of the Invention
The present invention relates to a mobile telephone powered by multiple batteries to extend mobile operation time.
2. Description of Related Art
Mobile telephones have become very popular due to their mobile nature. They are characterized by a compact body that allows them to easily fit in a purse or a pocket, or comfortably clip onto a belt, a purse strap or an article of clothing of a user. Mobile telephones pack their own power source and operate wirelessly over a voice/data network permitting direct communication anywhere within the network coverage area. Power is provided in the form of a rechargeable main battery functionally connected via the battery connector to the mobile telephone forming part of its compact body. The main battery, which provides the appropriate voltage to operate all the mobile telephone features, has a size, shape and weight that are constrained by the compact size, shape and weight of the mobile telephone body. Main batteries come in different sizes, shapes, weights, voltage outputs and battery connectors to match the diverse makes and models of mobile telephones.
The industry trend in mobile telephones is toward reducing their compact body size and weight while packing more features, such as internet surfing and downloading capabilities, playing music and video games, taking and transmitting still images and video clips, etc. Smaller telephones translate into smaller main batteries yet more power is needed to support the diverse features added. Advances in rechargeable battery chemistry have reduced the main battery size while increasing its power capacity. Reducing and managing power consumption in mobile telephones have contributed to a longer battery life. Yet, despite these improvements mobile voice communication is still measured in few hours. Using the added features is likely to consume more power further reducing mobile operation time.
The need for additional portable power for mobile telephones has been recognized. Solutions presented thus far do not adequately increase the mobile operation time in a truly mobile and continuous fashion such that no down period is needed for connecting the additional power and power to the mobile telephone is not interrupted during the connection process. An adequate mobile operation time is at least two times greater than the mobile operation time provided by the main battery. Also, current solutions tend to be mobile telephone make and to some extent model specific rendering them obsolete upon replacing the mobile telephone.
Auxiliary batteries, as a current solution, might barely double the mobile operation time, however, at the expense of increasing the mobile telephone size and weight going against the industry trend. Spare main batteries are limited in power capacity. Both auxiliary and spare batteries are constrained by the mobile telephone size and shape and thus tend to be mobile telephone specific. Besides, power to the mobile telephone is interrupted upon connecting spare batteries and possibly auxiliary batteries. Rapid portable battery chargers, whether mechanical or solar, provide only a limited increase in mobile operation time while requiring a down period for recharging.
Existing “portable” power supplies and power generators can properly increase the mobile operation time when connected to the mobile telephone main battery charging connector. However this is accomplished at the expense of sacrificing mobility, the greatest advantage a mobile telephone offers. The bulky nature of these power storing devices and their weight prevent their hands-free portability using clothing including clothing accessories of a mobile telephone user, for example, these devices do not fit in a pocket or comfortably clip onto a belt, a purse strap or such. Besides, when a mobile telephone is powered via the main battery charging connector, a power status is not displayed for the power source powering the mobile telephone and the main battery is constantly charged, unless full, decreasing its life cycle and power capacity.
More importantly, the crowding of existing portable power supplies and generators with features designed to make them useful and attractive reduces the maximum power that can be packed as a function of size upon reduction of these power sources to an acceptable portable size and weight for powering a mobile telephone due to a smaller place for the built-in battery. Crowding features for existing portable power supplies include: at least one electrical AC outlet, a DC power socket, an AC inverter to convert AC power to DC power, a high power DC connector, a high current capacity connector, protection against output overload and heating, an alarm to alert when the built-in battery is nearly discharged and a battery level indicator. Portable generator, in addition, have to accommodate mechanical or solar charging gear.
A portable generator, the FreeCharge power source from Freeplay Energy Corporation, has been reduced in size for use with mobile telephones. It's main disadvantage, as indicated above, is a small power capacity as a function of its size in order to accommodate the mechanical charging gear. The maximum power capacity of the FreeCharge power source is limited to 1000 mAh. Yet, this device, with a length of 5.7″ (144 mm), a height of 2″ (52 mm), a width of 2.4″ (60 mm) and a weight 8 oz (230 gram) is bigger and heavier than a standard mobile telephone comprising a battery carrying 1000 mAh. The bulky nature of the FreeCharge power source makes it unattractive for portability by a user considering its limited power capacity which requires frequent charging of the FreeCharge power source during extensive mobile operation of a mobile telephone, a process that can be exhaustive if done manually.