When is it ok to short a battery? : r/AskEngineers
The short answer is that it''s okay to short a battery with voltage V and internal resistance Ri for a time t if V 2 /Ri * t < 🔥 . The current you get is V/Ri and the power dissipated in the internal resistance is V 2 /Ri. That indeed causes self-heating, but if the internal resistance is high, sometimes that heat is negligible compared to the thermal mass of the battery.