If you know you are not going to be using an item for a long time that requires or has batteries, I would recommended to remove it. That way you avoid battery corrosion, like what happened to my spare mouse here.
This is true. I found a toy vanity on the curb. It had a switch to light up, but it didnt work. I figured it just needed new batteries and opened the compartment. The battery corrosion was terrible. I did clean off the battery compartment and put in fresh batteries and it works now. However, sometimes the corrosion ruins the item.
Yes, it is important to remove batteries because it can cause corrosion. You are right sometimes it could ruin the item too.