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Split charge relay burnt out

Posted: 23 Dec 2015, 16:32
by kit
I have a simple split charge relay fitted to trickle charge the leisure battery it is just a basic thing not zig or anything complex, anyway just checked the leisure battery and it is flat checked the fuse for relay and that was OK but on inspection the relay had a hole burnt in it, would anyone have an idea as to how this may of happened as I would not like for it cause a fire, thanks.

Re: Split charge relay burnt out

Posted: 23 Dec 2015, 16:35
by kit
This is what was fitted on there,

http://www.towsure.com/split-charge-rel ... wwodY6YLfQ" onclick="window.open(this.href);return false;

Re: Split charge relay burnt out

Posted: 23 Dec 2015, 18:00
by syncroandy
For an electrical component the blurb on the Towsure website is alarmingly free of technical specifications, however it mentions in passing not to exceed a current draw of 15 amps. A lead-acid battery can certainly exceed that current if charging from a source such as another battery or alternator, so I think the item is being mis-sold if they say its suitable for split battery charging. What fuse rating are you using ?

Re: Split charge relay burnt out

Posted: 23 Dec 2015, 18:34
by Oldiebut goodie
Exactly the reason why I say that split charges should be a minimum of 80A capability. Beefy cables leading to less voltage drop to the charge going to the leisure, plus plenty of leeway for that inevitable kick as a depleted leisure receives the hefty charge from the alternator and starter battery being connected.

To be fair to the advert it is aimed at the luggers who only have the puny wiring via the towbar connector setup.

Re: Split charge relay burnt out

Posted: 23 Dec 2015, 18:37
by CovKid
Agree, exactly what I've got on mine. Couldn't find anything as a kit that was up to the job so went heavy duty.

Re: Split charge relay burnt out

Posted: 23 Dec 2015, 18:52
by kit
The fuse is 20 amp and nothing other than the water pump for the sink and the phone charger is connected to the leisure battery but the battery is heavy duty.

Re: Split charge relay burnt out

Posted: 23 Dec 2015, 18:54
by kit
The towsure setup was on it when I bought 15 years ago so it has worked up until now but I was concerned to see it was burnt.

Re: Split charge relay burnt out

Posted: 23 Dec 2015, 19:20
by Oldiebut goodie
kit wrote:The fuse is 20 amp and nothing other than the water pump for the sink and the phone charger is connected to the leisure battery but the battery is heavy duty.
The fuse is higher than the units rating to start with! Then you wonder why the relay has burned out? A 12.5A one would have been the one to use. Or even a 10A.

Re: Split charge relay burnt out

Posted: 23 Dec 2015, 19:22
by kit
Thanks as I said the set up was already there, but a 10amp would be an improvement :ok

Re: Split charge relay burnt out

Posted: 23 Dec 2015, 19:29
by itchyfeet
kit wrote:Thanks as I said the set up was already there

A good reminder to people not to trust an old van to be safe,
check your fuses match your circuits, just like you check your brakes are ok when you buy a second hand vehicle.

:ok

Re: Split charge relay burnt out

Posted: 23 Dec 2015, 19:38
by kit
I have had it 15 years mate :D

Re: Split charge relay burnt out

Posted: 23 Dec 2015, 20:02
by itchyfeet
My point is lots of vans have modified wiring, yet we often buy a vehicle and trust it's safe without periodic checking as we would with brakes.

I hate to think of the headlight 'upgrades' that will haunt people in future because they were not fused right.

A fuse is there to blow only in the rare circumstance there is a fault or overload, it may only happen once every 15 years but it's there for a good reason.

Some T25 circuits ( 2 off on a petrol to the engine ) are not fused at all a fire waiting to happen if the wiring is not periodically checked for faults.

Re: Split charge relay burnt out

Posted: 23 Dec 2015, 20:15
by kit
Sorry I do appreciate the advice and I will re check over Xmas break, I know I had problems with the glow plug relay a few years back as it had been modified and it caused no end of problems. :ok

Re: Split charge relay burnt out

Posted: 23 Dec 2015, 20:21
by itchyfeet
your'e welcome Kit
:ok

Re: Split charge relay burnt out

Posted: 24 Dec 2015, 09:54
by kit
Oldie, if the leisure battery is nearly fully charged would it take less of a strain on the relay so it could work as just a trickle charge?