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.

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.

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.

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

This should be avoided at any time. When the battery has been in a washing machine, it is no longer fit to use. Please dispose of this battery.

Batteries will become unfit to use after they’ve been in the water. Usually however, a battery won’t leak inside the washing machine thanks to the safety valve - so chances of your textile being affected are minimal.

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.

Mixed use or leaving the battery in the appliance can cause battery leakage.

Mixing batteries causes an imbalance in the energy flow. Some batteries will overcompensate this by discharging faster than usual - greatly reducing their lifespan.

No. Condensation could cause damage to your batteries. Avoid putting batteries under extreme temperatures at all times.