Battery pack and electrical device

A battery pack, comprising:

• a plurality of battery cells;
• a separator, supporting the plurality of battery cells;
• and
• a case, accommodating the plurality of battery cells and the separator, wherein
• the separator is configured to cover upper portions of the plurality of battery cells and expose lower portions of the plurality of battery cells, and
• the case has an inner surface portion that makes surface contact with side surfaces of the plurality of battery cells exposed from the separator.

A battery pack, comprising:

• a plurality of battery cells, comprising a first battery cell and a second battery cell;
• a separator, supporting the plurality of battery cells;
• and
• a case, accommodating the plurality of battery cells and the separator, wherein
• the separator is configured to cover upper portions of the plurality of battery cells and expose lower portions of the plurality of battery cells, and
• the case comprises
• an inner surface having a plurality of inner fins facing the second battery cell and extending in a direction intersecting a length direction of the second battery cell or extending in parallel to the length direction, and an inner surface portion facing the first battery cell and parallel to a length direction of the first battery cell, and
• an outer surface having an outer surface portion located on a side opposite to the plurality of inner fins and a plurality of outer fins located on a side opposite to the inner surface portion.