An electronic device (112, 500), comprising: a peripheral connector (114, 502) connectable to a peripheral bus; a bus interface coupled to the peripheral connector (114, 502), the peripheral connector providing a power line (DC PWR), a ground line and a plurality of data lines (DP, DM) to said bus interface; an available power detector connected to said bus interface; and power-consuming circuitry (118, 514); characterised in that: said available power detector operates to detect a level of available power from the power line (DC PWR) by obtaining analog voltage levels on the plurality of data lines (DP, DM) when a power source is connected to said bus interface via the peripheral connector, and converting the obtained analog voltage levels to at least one digital value indicative of the level of available power, wherein the level of available power indicated by the analog voltage levels is one of at least three gradations of different power levels that the electronic device is capable of identifying; the device further comprising a power manager (116, 512) connected to said available power detector and said power-consuming circuitry (118, 514), wherein said power manager (116, 512) operates to manage power utilization by at least a portion of said power-consuming circuitry (118, 514) based on the level of available power. a peripheral connector (114, 502) connectable to a peripheral bus; a bus interface coupled to the peripheral connector (114, 502), the peripheral connector providing a power line (DC PWR), a ground line and a plurality of data lines (DP, DM) to said bus interface; an available power detector connected to said bus interface; and power-consuming circuitry (118, 514); characterised in that: said available power detector operates to detect a level of available power from the power line (DC PWR) by obtaining analog voltage levels on the plurality of data lines (DP, DM) when a power source is connected to said bus interface via the peripheral connector, and converting the obtained analog voltage levels to at least one digital value indicative of the level of available power, wherein the level of available power indicated by the analog voltage levels is one of at least three gradations of different power levels that the electronic device is capable of identifying; the device further comprising a power manager (116, 512) connected to said available power detector and said power-consuming circuitry (118, 514), wherein said power manager (116, 512) operates to manage power utilization by at least a portion of said power-consuming circuitry (118, 514) based on the level of available power. said available power detector operates to detect a level of available power from the power line (DC PWR) by obtaining analog voltage levels on the plurality of data lines (DP, DM) when a power source is connected to said bus interface via the peripheral connector, and converting the obtained analog voltage levels to at least one digital value indicative of the level of available power, wherein the level of available power indicated by the analog voltage levels is one of at least three gradations of different power levels that the electronic device is capable of identifying; the device further comprising a power manager (116, 512) connected to said available power detector and said power-consuming circuitry (118, 514), wherein said power manager (116, 512) operates to manage power utilization by at least a portion of said power-consuming circuitry (118, 514) based on the level of available power.