Uploading photos to Google Drive

Thanks you for your reply.  I’ve now had success in uploading four files from both my tab and my phone - but it is quite slow.  I now see that this was my previous problem - I wasn’t waiting long enough for the files to completely upload.

Given the length of time it would take to bulk load, I’m thinking that the best time to do it would be overnight - do you think it would be ok to use the drive plugged in to a wall socket whilst doing this, or would this not be good for the battery?