The normal self-discharge of a battery is due to the structural factors of the battery itself, such as impurities in the electrolyte, the presence of contaminants, or the partial detachment of active materials inside the battery, which settle at the bottom, causing the positive and negative plates to discharge through sedimentation. If a battery is not used for a long time, it will slowly discharge on its own; therefore, the car should be started periodically to charge the battery.

Maintenance of UPS (uninterruptible power supply) is essential to ensure its stable operation and extend its service life. The following are some main maintenance methods: