Anyone know auto electrics?

[rocker]

Hi all, a mate of mine has a band van, basically he drives bands around the country, and it has 230v in the back, which is all kosher safety wise etc, BUT he wants to have a seperate 'leisure' battery that charges from the motor like the normal battery, and put everything on that to take the pressure off the normal battery etc. I know this can be done as it is in mobile homes and things, and the 230v side I'm all OK with obviously but I don't now where to start with the car side of things! Can anyone offer any advice? Just to clarify the 230v needs to be on in the back when the van is driving and stationary (as long as the batt lasts).

 

[Ponty Massive]

Not sure if there's anything specific out there (must be I suppose). I would guess to wire the leisure battery in parallel with the van battery with some sort of diode pack or manual isolator between to stop any 240v stuff being drawn from the van battery. May have to beef up the alternator as well??

 

[UNG]

What you need is a split charge relay usually bought as a kit this will allow the leisure battery to be charged while the vehicles engine is running but will not draw current from the vehicles battery when the engine is not running. It's the same kit that is used for the 12S socket charging connection on a towbar installation

 

[rocker]

Thanks dudes, I think that split charge relay is definitely the way to go.

 

[jeremy]

Take advice on the choice of leisure battery as I seem to remember from my car radio/alarm days something about deep cycle batteries? or I may be imagining it!

 

[UNG]

Leisure batteries are generally designed as deep cycle / discharge although the design and duty of the cells vary from battery to battery. Also you have a choice of wet cell technology or the absorbed glass mat technology. The main issue is having sufficient standby battery capacity for the load being used

The alternative may be an engine mounted alternator with a 240v output and an engine runlock fitted to allow removal of the keys from the ignition while the engine is running