Battery pack

A battery pack comprising:

• a plurality of cylindrical batteries;
• a heat absorbing member disposed between one cylindrical battery and another cylindrical battery of the plurality of cylindrical batteries;
• and
• a battery holder that houses the plurality of cylindrical batteries and the heat absorbing member,
• wherein
• the battery holder includes an enclosure along an outer periphery of the plurality of cylindrical batteries,
• a plurality of protrusions are provided on an inner surface of the enclosure, and
• the plurality of protrusions are provided along a circumferential direction of the cylindrical battery housed in the battery holder, and are provided along an axial direction of the cylindrical battery housed in the battery holder.

A battery pack comprising:

• a plurality of cylindrical batteries;
• a heat absorbing member disposed between one cylindrical battery and another cylindrical battery of the plurality of cylindrical batteries;
• and
• a battery holder that houses the plurality of cylindrical batteries and the heat absorbing member,
• wherein
• the battery holder includes an enclosure along an outer periphery of the plurality of cylindrical batteries,
• a plurality of protrusions are provided on an inner surface of the enclosure of the battery holder, a first groove extending along an axial direction of the cylindrical battery housed in the battery holder and a second groove extending along a circumferential direction of the cylindrical battery housed in the battery holder are provided on the inner surface of the enclosure of the battery holder, and
• the protrusion includes a portion surrounded by the first groove and the second groove.