Battery state control circuit, battery state control device, and battery pack

A battery state control circuit for connection to multiple rechargeable batteries, the

• multiple batteries being connected in series, for connection to a primary coil connected in series to the multiple batteries, and for connection to multiple secondary coils to which electrical energy stored in the primary coil is transferred, the multiple secondary coils being connected in parallel to the multiple batteries, respectively, the battery state control circuit comprising:
• an adjustment unit to adjust the energy amount stored in the primary coil, in accordance with a state of at least one of the multiple batteries;
• a drive switching element connected in series to the primary coil;
• and
• a control unit to control switching ON/OFF of the drive switching element,
• wherein the control unit keeps the drive switching element in an off state, so that the
• adjustment unit sets the energy amount to be zero, and wherein the primary coil repeats a cycle of storing and releasing the energy stored in the primary coil, and the adjustment unit adjusts a length of a storing period during which the primary coil stores the energy, relative to the cycle, in accordance with the state of said at least one of the multiple batteries.

A battery pack comprising:

• a battery assembly having multiple rechargeable batteries, the multiple batteries being connected in series;
• a transformer, connected to the battery assembly, the transformer including
• a primary coil connected in series to the multiple batteries;
• and
• multiple secondary coils to which electrical energy stored in the primary coil is transferred, the multiple secondary coils being connected in parallel to the multiple batteries, respectively, and
• a battery state control circuit for connection to the multiple batteries, the primary coil, and the multiple secondary coils, the battery state control circuit including
• an adjustment unit to adjust the energy amount stored in the primary coil, in accordance with a state of at least one of the multiple batteries,
• wherein the primary coil repeats a cycle of storing and releasing the energy stored in the primary coil, and
• wherein the adjustment unit adjusts a length of a storing period during which the primary coil stores the energy, relative to the cycle, in accordance with the state of said at least one of the multiple batteries.