Hi, I could use some help please. I've got a leisure battery fitted with campsite hookup for electricity. On a recent camping trip all was well until two days in when the cigarette lighter devices (phones/sat nav) stopped charging. Electricity was fine, just no juice coming into cigarette lighters. Got home and I noticed the leisure battery was completely flat and the top fuse in the diagram attached was blown. It goes into the "2" on the relay but I don't really know what that means... I replaced the fuse and same again. It blows. I've charged my leisure battery fully and cigarette lighter devices now work fine so I've got a few issues here.. 1. The leisure battery doesn't charge whilst driving 2. The top 15amp fuse in my picture keeps blowing when I turn key to ignition. I've checked all the earths and they seem spot on. Any advice please? Best wishes Elizabeth
If the leisure battery is very flat the. It will pull a big current initially and blow the fuse. I am not sure what setup you have but 15 amps seems low for a split charge fuse. I have 48 amp cable and 30 amp fuses in mine.
Have you got the signal for the relay from the coil or any source that goes instantly live with the ignition switch, if this is the case the starter motor will pull on your leasure battery and blow the fuse whatever size it is, It will do this when your main battery is down a bit. If this is the case simply change the signal from your ignition live source to the feed for the generator light on the dash which only comes on when the starter is disconnected.
Do you know how it's wired. A sketch would make fault finding so much easier. Added twice, rubbish phone.
More or less covered above. Relay is operated by your ignition and therefore at any time the ignition is switched on the positive sides of the batteries are connected together, and to the output of the alternator. As stated above if the leisure battery is discharged then on switching on the ignition then greater than 15 amps is likely to flow as the battery draws current to charge itself. The issues are: . fuse is rated to low (and potentially the wiring also) . the relay really needs to operating when the engine is running and the alternator charging, usually these are operated from the alternator options are - .check cable rating and relay rating and if possible increase fuse size to highest possible ie less than the ratings for the relay and the cable and wire the sensing cable to the alternator and not the ignition (probably on the coil) . if rated to low junk and start again. I would advise a voltage sensing relay is the one to go for.
Just googled and relay is only rated at 15 amps. this is too low. Id recommend junking it and starting again!
I just want to say thank you for all the views and advice here. All taken on board. I "think" I have solved the issue. Listening to what was said above my gut feel was that I had suffered an electrical surge of sort some camping which blew the particular relay fuse and then charging from flat was resulting in the same 15amp fuse blowing due to the initial burst required to kick it into life from zilch electricity. So I left the fuse out, charged the leisure battery up fully and then tried with 30amp fuse in, and it worked, then I tried with 15amp fuse in and it worked fine.. Fingers crossed it is now fine..certainly seems to be but I can't tell if its charging or not since I haven't gone wild camping since this incident...that's coming up next weekend at Feastival in Cotswolds.. Thanks all. Elizabeth x
If you haven't already you need to fit something like this wired from your leisure battery to give some indication of state of the battery. My setup is bad ( leisure battery is too small and the radio drains it regularly) but I can see how low it gets and can check its charging when driving or plugged into a hook up.
I've got one there's loads on e bay @pkrboo got mine for me (I owe you a beer) I switched mine on the live so I could turn it off at night etc.
If you have the relay wired to a an ignition live crossing your fingers wont help, it will blow as soon as your main battery gets low, check out @matty 's link above and pick it up from your alternator,
...and to add to the above, sort out the wiring & fuses properly. Charging with no fuse protection on the cable is stupid. Sorry if that's harsh but watch the following video if you need convincing that 12vDC requires respect
