A battery pack comprises a plurality of lithium polymer cells (110, 112, 114, 116; 210, 212, 214, 216; 310, 310A, 312, 312A, 314, 314A, 316, 316A; 410), a charger (232, 332, 432) connected to the plurality of lithium polymer cells, a spread spectrum oscillator (204) connected to the charger, a battery condition indicator and controller (248) connected to the charger, a first order battery protection circuit (250, 350), and a second order battery protection circuit (252, 352) connected to at least one of the plurality of lithium polymer cells and a thermal fuse (224, 324, 424). The first order battery protection circuit (250, 350) is connected to elements selected from the group consisting of: the battery condition indicator and controller (248), at least one sensor (256, 258, 260, 264, 266; 358, 372) connected to the at least one of the plurality of lithium polymer cells, a cell balance circuit (254, 354) connected to the at least one of the plurality of lithium polymer cells, and a battery disconnect switch (246).
展开▼
