As seen here: Accumate charger (Amazon) (http://www.amazon.co.uk/gp/product/B0026JITIS?ie=UTF8&tag=nextas-21&linkCode=as2&camp=1634&creative=19450&creativeASIN=B0026JITIS)
Yes, it's £45, but in the end I decided to give in and try it. It's currently recovering a type 043 battery (MG Midget-style) which was left discharged for a little while (don't do that, it's a really bad idea) and is therefore sulfated. I'll post back here as to how successful it is!
It hasn't recovered that battery, but it's a much better charger to use on my leisure battery (than the car charger I had been using) it seems. After the last charge I got about 1.5x the range I used to, which is brilliant!
Yeah lead acid batteries really are fussy things. I use the original charges and other hi tech pulse charges and set up a C5 charging station so they are out of the house but under cover - they are on charge 24/7 so I'm hoping that they will last me.