I have just bought a digital multimeter in maplins for £8.62. There is one on offer for £6 but doesn't include battery. My rac charger meter worked fine.
The Sterling charger that we have bought recently is 4 stage and can deliver 10amps , so can replace the on-board charger should it be necessary. As we are off to deepest darkest Scandinavia for 3 months next year we are backing up all systems!
Well, I've lashed out on a charger from Halfords (£30). An automatic charger that senses the battery state and can be left connected for long periods keeping the battery charged as neccessary. Says it charges all lead acid batteries including deep cycle leisure batteries sealed or otherwise, so it should do the trick. Only has led lights to indicate charging or charged, so I may have to invest in a voltometer as well just to keep an eye on the battery condition.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.