It is not necessary to refill a battery after it has been charged, unless specifically recommended by the manufacturer of the battery.

In modern batteries, such as lithium-ion batteries that are often used in electronic devices, it is usually not possible to refill them. These batteries are designed to be repeatedly charged and discharged without the need to add extra fluid or electrolyte.

In the past, there were lead-acid batteries that could be refilled. These batteries had an electrolyte fluid that could evaporate or decrease over time. In that case, you needed to add distilled water to bring the electrolyte level back up.

It is always important to follow the manufacturer's instructions regarding the maintenance and use of the battery. If there are specific instructions to refill the battery after charging, you should follow them.