Bongo Fury

how long does a leisure battery last if your just running a dvd player or tv and lights.

Depends on the battery capacity. It will last a lot longer if you don't use the DVD -electric motors use a lot more power than lights and TV alone.
You can work it out using "wattage divided by voltage=amperage". Find the wattage of the various items and divide it by 12 to get the Amp'hr figure.

Hi,

It's hard to answer exactly, many factors involved.

When I researched it I was told a normal LB should only be discharged max 50%, unless it was a more expensive "deep cycle" type.

So say you have a 100AH (amp hours)battery you have really around 50 to play with before you damage it.

So if your DVD takes 1Amp you have 50 hours use.

I can't recall the figures but a good digital voltmeter can be used to give you more accurate state of charge, or you could wire the DVD via a battery protector that shuts that circuit down when the battery gets too low, leaving enough juice to start the engine.

More info on the voltage and charge state here:
http://www.c-realevents.demon.co.uk/battleaf.htm

I think there is a fact sheet that tells you all about it. Worth a look

Lights will help a lot if they are LED spots as they tend to be less than 1 watt, whereas halogen spots are usually 10w - the 5w ones are very dim.