Why should batteries never be stored loose in a tool bag?

Batteries should never be stored loose in a tool bag primarily because loose batteries can cause the terminals to short out. When the terminals of a battery come into contact with conductive materials or other batteries, it can create a short circuit. This short circuit can generate heat and potentially lead to a fire, posing a significant safety hazard. Proper storage solutions, such as battery cases or compartments, are essential to prevent this dangerous situation, ensuring that batteries are kept separate and secure.

While it is also true that batteries can lose their charge quickly when stored loosely, or that they may leak acid which can cause damage, the most immediate and hazardous concern is the risk of a fire due to short-circuiting terminals. Additionally, while special handling may be required for certain types of batteries, the primary danger associated with storing them loose is related to the risk of shorting and resulting fires.