Change the batteries as soon as the device starts malfunctioning. Remove the batteries if you plan on not using the device for a longer period of time.

The capacity of batteries is indicated as XXXX mAh (milliampere/hour). If you insert this battery into an appliance which consumes 100 milliampere current continuously, the operating time of the appliance will be around 20 hours mathematically.

This is a vibration noise which occurs when electric current flows through a transformer or a winding wire inside a component part. However, the charger may still be used without any concern as there is no need to worry from a safety point of view.

Batteries are classified according to IEC classification standards: LR03 is equal to AAA, but in another standard.

Yes. All batteries have an expiration date, beyond which their performance decreases.

Expiry date indicates how long the battery will function properly according to industry standards.

In case of skin contact there is a chance of chemical burns. Use clear tepid water for at least 15 minutes on exposed skin. Consult a physician in case of irritation, injury or pain. In case of contact with the eye, do not rub the eyes, but flush with clear tepid water for at least 30 minutes and consult a medical professional immediately.

This is a guarantee that no mercury is added during production.

Make sure you measure the correct way: connect the poles to their corresponding measuring ends.

A hot battery could have several causes: from wrong storage to short circuiting. Some warmth is okay but keep an eye out for unusual heat.