Battery pack management apparatus selectively controlling battery cells

1. A battery pack management apparatus for managing a battery pack, in which a plurality of battery cells are electrically connected to each other, the battery pack management apparatus comprising:

a measurement unit configured to measure a number of charging and discharging cycles of each of the plurality of battery cells performed at a first C-rate;

a selection unit configured to select at least some battery cells from among battery cells whose number of charging and discharging cycles measured by the measurement unit reached a reference number;

a blocking unit configured to stop operations of only the at least some battery cells selected by the selection unit for a first reference time while the battery pack management apparatus continues charging and discharging battery cells whose number of charging and discharging cycle have not reached the reference number; and

a speed reduction unit configured to, when the operations of the at least some battery cells stopped by the blocking unit are resumed, perform charging and discharging of the at least some battery cells for a second reference time at a second C-rate lower than the first C-rate before being stopped,

wherein after the second reference time has elapsed, the at least some battery cells are charged and discharged at a C-rate higher than the second C-rate.

2. The battery pack management apparatus of claim 1 , wherein the second reference time is one charging and discharging cycle.

3. The battery pack management apparatus of claim 1 , wherein the speed reduction unit is configured to, when the stopped operations of the at least some battery cells are resumed, perform charging and discharging for the second reference time at half or less the first C-rate before being stopped.

4. The battery pack management apparatus of claim 1 , wherein the selection unit is configured to sequentially select battery cells one by one when there are a plurality of battery cells whose number of charging and discharging cycles reached the reference number.

5. The battery pack management apparatus of claim 1 , wherein the reference number is set to be at least one of 200 to 400.

6. The battery pack management apparatus of claim 1 , wherein the first reference time is set to be at least one of 2 days to 4 days.

7. The battery pack management apparatus of claim 1 , wherein two or more of the reference numbers are set.

8. The battery pack management apparatus of claim 1 , wherein the blocking unit comprises a switching device that turns on or off an electric connection of each of the plurality of battery cells, and is configured to stop or resume an operation of each of the plurality of battery cells by controlling the switching device.

9. A battery pack comprising the battery pack management apparatus of claim 1 .

10. A power storage apparatus comprising the battery pack management apparatus of claim 1 .

11. A battery pack management method for managing a battery pack, in which a plurality of battery cells are electrically connected to each other, the battery pack management method comprising:

measuring a number of charging and discharging cycles of each of the plurality of battery cells performed at a first C-rate;

selecting at least some battery cells from among battery cells whose number of charging and discharging cycles measured in the measuring reached a reference number;

stopping operations of only the at least some battery cells selected in the selecting for a first reference time while continuing charging and discharging battery cells whose number of charging and discharging cycle have not reached the reference number; then

resuming operations of the at least some battery cells by performing charging and discharging for a second reference time at a second C-rate lower than the first C-rate before being stopped; and

wherein after the second reference time has elapsed, performing charging and discharging of the at least some battery cells at a C-rate higher than the second C-rate.