Thread: Portable jump starters, any good

Looking at buying one of the small car jump starters, something like Certa 12000 mAh portable jump starter. Do these things work?. Reason is last winter on a extended road trip I was camping on a DOC site 3 nights, charged phone, used car radio a lot and when it was time to leave flat battery. It is a small car and I managed to push it to the track/road out which was down hill and jump started it. Now I have a van and I wont be able to push that. Thought about split charger and 2 batteries, but then thought this may be the way to go, easy cheap. Do they do what it says on the tin, would one get my 2ltr petrol Hiace to start when I stuff up and flatten battery. Thoughts please