The fabrickit Coin Cell Brick uses a lithium-ion battery for power
storage. As with all lithium-ion batteries, there are serious safety
concerns. Improper use of the Coin Cell brick can cause damage to the
brick or other electronic components. Improper use or charging can
cause the Coin Cell brick to become very hot, catch fire, vent hot
gases, or explode.

Familiarize yourself with and observe the following safety instructions:

Do not charge the Coin Cell brick while it is being worn.

Monitor the Coin Cell brick while charging.

Do not leave it charging unattended.

Disconnect the USB cable from the Coin Cell brick as soon as charging finishes.

Do not expose the Coin Cell Brick to temperatures below 0 degrees C
(32 degrees F) or above 45 degrees C (113 degrees F).

Do not directly connect ("short") the Coin Cell brick's outputs or
battery terminals to each other.