when does bladder control start?

[CarolinaMoose]

ds is 20mo and at a friend's suggestion, I've been leaving his nappy off for an hour or so at a time esp when he's playing in the garden so he can see when he's done a wee or a poo.

I've noticed that if he's had a fair bit to drink, he tends to do 3-4 separate puddles of wee over maybe 5-10 mins, as if his bladder's overflowing a bit, then a bit more etc.

I don't want to start potty training if it means putting him on this often, so what kind of age do they start doing grown-up style wees, where it all comes out at once iyswim?

Or is that consciously learnt?

It varies, but the more they drink the stronger the bladder gets

also some drinks irritate the bladder and then they will wee more frequently

what sort of age range zippi?

(it was water btw!)