Yes, there is an option to backup photos when system is Idle. Go to settings window, check mark ‘Upload when idle’ and you are good to go. Whenever PicBackMan finds your system idle, it will upload and backup photos & videos to your associated online accounts. This feature allows you to conserve bandwidth. Once this is enabled, PicBackMan will only upload when your system is not in use.
PicBackMan is a free photo/video uploader that helps you to keep your memories backed up to your favorite online services.
Users in 130+ countries have backed up.
... an excellent job of uploading more then 300GB of photos to 2 different services