Power supplies for portable electrical devices.

摘要

A portable computer main body (10) includes a power source circuit section (46) having a battery pack. A plurality of auxiliary battery units (16-1, 16-2) are mechanically connected and fixed to a casing of the computer main body and are electrically connected in series to a power source input terminal (48) of the main body (10). A charge/discharge control section (52-1, 52-2) is provided for each of the auxiliary battery units (16-1, 16-2). During charging, the charge/discharge control sections cooperate to charge the auxiliary battery units sequentially starting from the auxiliary battery unit (16-1) located nearest to the computer main body (10). On the contrary, during discharging (use of the computer) the charge/discharge control sections cooperate to discharge the auxiliary battery units sequentially starting from the auxiliary battery unit (16-2) which is furthest from the computer main body. There is also another system construction having a single auxiliary battery. <IMAGE>