FIELD: power supplies for portable devices including portable phones. SUBSTANCE: method for battery charging involves multistep charging procedure including compensating charge step, fast charge step, and maximum charge step. Internal battery is charges to almost full capacity by compensating charge (if required) followed by fast charge. External battery is charged in similar way to almost full capacity. A device is also proposed for charging internal and external batteries of portable phone that has control unit, external voltage input, and microcontroller. EFFECT: reduced time of charge. 10 cl, 5 dwg, 3 tbl
