Never charge Ni-MH batteries with a Ni-Cd charger. There are significant differences in charging conditions between those two types of batteries.

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

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.

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.

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.

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

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.

There are some best cases to keep stored batteries in best shape: store them in their original packaging, never mix up different batteries and store them at room temperature or in a cool environment.

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

The smart charge function on chargers checks the charging conditions of the batteries, the temperatures of both the batteries and the charger, etc. This allows the charger to individually charge each battery under the best conditions. This function shortens the charging time by 5% compared to the chargers without such function.