I presently have a 110 ah leisure battery in my caravan what I need to know is, can I replace it with a smaller an lighter car battery as I'm always on hook up, or could I do away with a battery altogether
Yes you can replace the 110Ah battery with a smaller one, but do not use a car battery, they are a different design and do not take kindly to the caravan type duty. You should use a leisure type battery.
Unless the weight of the 110 battery is an absolute problem, I suggest you stick with the 110 until it needs to be replaced.
We had a boat for many years before changing to the caravan. We started off with lots of battery capacity but as the years went by and we realised that for over 90% of the time we were on hook-up, we downsized and ended up with just one heavy duty 70amp hour battery listed as a diesel engine battery. Still perfect 3 years later.
A leisure battery is designed for continual discharging and recharging which you are not doing.
There are many good links to do with 12v electrics on the www.pbo.co.uk web site and you can also read all the postings on the various forums. Also have a look in the boating section on e-bay and you'll find several firms advertising in the listings.
We've been held up on route and had to spend a night in a sites late arrival holding area with no electric. We've had electric tripped on the sites supply and been glad to have the battery as well as people ( may be kids ) un plug the supply at night. We've also arrived at a site who had us booked in wrongly as not needing electric, so had to run on batteries for a day or so.
In France we have also had very low electric power supply, so its been good to run the battery lights rather than share power for the fridge and other stuff.