First of all, not all battery cells are rechargeable. If yours is one, then you do not have to pluck them out to recharge. As they are tiny and sensitive, it is more logical to plug the charger into the device to recharge. Besides, you should only rely on the manual you have got with the device. It must have written the recharging guidelines to make the process convenient. For example, Lithium-based button cells have precise chargers that are commercially accessible. Any unintentional overcharging can lead to a threat of explosion. So, you should restrain them from charging spontaneously. Likewise, you should be up-to-date with the type of cells you own.