Leisure Battery Wiring Diagram check

Discussion in 'Mech Tech' started by Lofty, May 19, 2013.

  1. Guys/Gals
    Would you mind having a look at the following diagram and providing feedback. I think it is OK based upon previous threads I have read. I already have a JK relay with a wire running under the van to a fuse box behind the dash. I don't know the rating of the JK relay but I presume it will be man enough for the job but I do not know the wire rating of the cable used so I plant to star afresh on the wiring. So, Relay will go close to main battery with in line fuse (30A) between Main battery and relay and then again between Leisure battery and relay. Cable from Leisure battery through spare wheel well to a fuse box in the Cupboard. All cables 30A ish. Cables running from Fuse box to various items using either 17A cable or lower for lights and pump. Size of cable is throwing me a little though. Is it OK to use 17A cable (with a low rated fuse) for say the lights that have a very low power requirement or should I use a low Amp cable ?
    Many thanks
    [​IMG]
     
  2. Its fine to use bigger cable than you need if thats what you've got.
    30A should be ok for the relay fuse assuming the relay is rated at 30A or higher
     
  3. matty

    matty Supporter

    Looks ok to me
    The Jk kit is pants the relay is rated at 20amp and the cables that come with it are too small so you may have issues if you drain the battery right down and it trys to charge .

    i would use R30AF
    http://www.vehicle-wiring-products.eu/VWP-onlinestore/relays/relays.php

    then Ref 16. 32/0.20mm, 1mm2, 16.5amp. for the curcuits
    and Ref 39. 56/0.30mm, 4mm2, 39amp. to the fuse box from the battery and between the batterys
    http://www.vehicle-wiring-products.eu/VWP-onlinestore/cable/thinwall.php

    I like to run 2 core cable from the fuse box a live and a neutral and have a central neutral point near the fuse box
    it also means you dont have to drill for a neutral at every fitting handy for lights fitted in wood.
    CM216 2 32/0.20 (1mm2) 16 5.5mm
    http://www.vehicle-wiring-products.eu/VWP-onlinestore/cable/multicorecable.php
     
  4. Looks good to me too, and as matty said would use a better relay than the JK one.

    My only comment would be to add another in line fuse on the cable from the leisure battery to the fuse box, and to make sure you fit all the in line fuses as close to the batteries as possible - so you would have three in line fuses in total in your diagram (both ends of split charge circuit, and from leisure batt to fusebox).

    I've also done similar to matty and have a couple of multi-terminal neutral blocks in the places where most things connect in (e.g. one in kitchen unit, and one under the dash) as this makes things a lot easier for wiring up. I've actually put in two fuse boxes to make the wiring easier - one is by kitchen unit that that leisure battery runs to and fridge, heater, tap etc connect in to, and then I have a fused feed out from that fusebox up to another one under the dash where the radio, 12v accessory socket and lights etc. connect in.

    One further step I've done is add a switch on the dash that toggles the power for the radio and the 12v accessory socket between the leisure battery and the main battery in order to let me use it as a daily driver if need be without having to have the leisure battery in.

    Nick...
     
  5. Cheers Guys
    Taking the advice I will go for a new relay as I do not have 240 hook up so the battery may go fairly low.
    I think I will stick with single core as the longest runs are to places where the earthing point already exists so this will save a few £s. I have some 17A wire already that I can use as an earth cable for any new locations if needed.
    I also forgot the 5A fuse in the alternator feed. I assume I still need this ?
    Matty, does your schematic from your original instruction post refer to the relay you mention above ?
     
  6. matty

    matty Supporter

    I dont normally bother fuseing the alt switch wire
    The relay i linked to has a built in fuse so no need to add any more fuses but if you do fit them as close to the battery's as you can
     
  7.  
  8. Without a fuse right next to the leisure battery, if the wire from the leisure battery to the fuse box gets shorted in any way you (e.g. falls off at fusebox end and shorts to the body, or gets chaffed around where it comes through the body from the engine bay and so shorts against the body) you'll have a problem. If however a fuse is there and the wire shorts it will just blow the fuse.

    You basically want a fuse as close to both batteries as possible for all in or out connections.
     
  9. Cheers Nick. Understand.
    Another 30A fuse and holder to the list.
     
  10. OK so I went to buy some bits and then got confused on the fuse ! Do I buy 30A continuous and therefore 60A Fusing, or 15A continuous and 30A fusing. I'm guessing the latter.
     
  11. I'd go for the higher rated one as that leaves things more flexible for you adding things in the future, but it will still blow should any of the main connections short out. Matty might be able to advise better than me on this though.
     
  12. matty
    could you advise here please. I was thinking just inline splash proof holders with blade fuses but I need a littl ehelp on which fuse is the right one.
     
  13. matty

    matty Supporter

    That will be fine a 30amp green fuse will be all you need
     

Share This Page