Hi this may be a bit long, sorry!
Background - been divorced several years, three children, one of whom is still under 16. Ex-h has never paid maintenance because he was self-employed so claimed to be skint most of the time. CSA couldn't help.
I rent a house and have worked since divorce to support myself and DC, did have some help from tax credits.
Ex-h bought a house after inheriting money a couple of years ago and has recently got a full-time job. Since the divorce he's rarely had all the DC to stay overnight together as it's a two bed house. The older two DC are near enough grown-up and do their own thing, although still live with me.
We are both in new relationships, not that it makes much difference. My partner has effectively contributed towards our household expenses, but not towards my DC. Ex-h's partner lives with him. I obviously don't know his income but it's probably more than mine.
I recently asked ex if he'd be willing now to regularly contribute for our child who is still at school. He's having 'a think' about it 
.
How long should I leave him to 'think'? I hate having any contact with him tbh due to the nature of the break-up (he assaulted me, so the less I have to see/speak to him the better). The DC are old enough to make arrangements with him directly so I don't need to talk to him about their care etc.
One comment I think may have come from him via the DC is that I get child benefit so why would I need more money?
Any words of advice please?