starter?

[omodos]

Got a weird one, always had a slow turnover when starting the engine...sort of laboured and gets worse in winter so will be changing out battery soo, according to OBC all good ranging from 13.8-14.1v depending on what i run....ok so the other day started car and made the mistake of keeping the key in the start position even though engine had started...since that day I am getting a much faster start and a different noise from the the starter motor....have no idea why or if this is bad? checked the obc before starting to see if the readings are out after this change, and they are all in range....could the starter actual stick and have been unstuck with this key turning i did? or could it even be my battery on its last legs/