Leisure Battery

If you notice an eggy smell in your caravan or motorhome. It maybe a sigh that your leisure battery is cooking and needs to be disconnected and removed quickly. If left you risk your unit catching fire and ending your holidays early.

Common reasons for overheating include:

Overcharging: Faulty smart chargers, solar controllers, or alternator regulators can supply too much voltage/current. This causes rapid gassing (in lead-acid batteries) and excess heat.

Dead or Shorted Cells: Internal plates can degrade and short circuit. This forces the entire electrical current to push through the remaining healthy cells, causing boiling and extreme temperatures.

Old Age: As lead-acid and lithium batteries age, their internal resistance naturally increases, meaning they generate more heat for the same amount of charging or discharging.

Environmental & Ventilation Issues: Storing batteries in unventilated compartments or exposing them to direct summer heat limits heat dissipation.

Excessive Discharge: Pulling heavy loads (e.g., inverters) faster than the battery is rated for causes rapid internal heating.

What to do next:

If your leisure battery is hot to the touch or giving off a strong "rotten egg" (sulfur) smell, disconnect it immediately and move it to a safe, well-ventilated area. A boiling battery poses severe fire, explosion, and toxic gas risks.