One week a year we go to a festival where there will not be any elec hook up. A previous owner retro fitted some LED strip lights that run off the battery and I have fitted a USB charge port that will be used sparingly to charge phones. There is also the water pump that I guess will continue to work. Roughly how many days would you expect a battery to last if I just used it for LED lights 30 mins a day when going to bed (the event is peak summer) and to charge a phone occasionally? Would it last the week or do I need to go find some kind of solar panel kit to top up? Thanks

My battery (not a leisure one) would easily last 1 week, I suspect a lot more. Exactly your usage. Can you give it a trial at home ?

Steve