Interesting reading this has I was going to wire the pumps straight to my battery has my new van has the battery under the passenger seat and was pretty convenient. But I still dont trust parking up spending a few hours on an apt block and then try to fire the van up. Obviously it does work for some.
I've just bought my third leisure battery in 2.5 years. Planning on fitting a split relay but to be honest taking the Battery out every other night isn't really any hassle and feel I have peace of mind that the van and pumps will see me through the day.
A point to remember is, if you do clock a few miles a day then the battery will probably keep up, but I tend to do short journey's quite a few stop starts.
Wayne