I use only Deltran Battery Tenders, but it depends on the type of battery you have. I have 5 Deltran single car charges, but they do make a multi car box as well. I find these are just plain reliable. I even have one Deltran I ran over. The case is all dented and smushed (technical term?)and it looks like garbage but it still works just fine. However, it may not be a viable product in the UK? Don't know.
Cheers,
