Smartcom heavy duty unit clicking

[Ads1987]

Do you see any problem with running the spot lights from the leisure battery, at the moment it only runs the interior lights and the pump for the sink which I'm assuming don't use a large amount of power, just thinking it probably best to run as little as possible from the starter battery?

[California Dreamin]

Hi
By 'Spot Lamps' I assume you are not talking about interior spots? but exterior lamps mounted on the bumper?

If it's external 55watt type I wouldn't consider it normal practice to wire them to the leisure not that it is going to make much difference as both leisure and starter batteries are effective ONE BIG battery when the engine is running as the SMARTCOM relay just connects the two together.

There really isn't a benefit wiring them this way...but neither is there a negative assuming the split charge wiring is rated high enough to cope.

Martin

[CJH]

Don't rule out poor earths to the body...

It was a poor earth!

With the smartcom relay fuse removed so that the leisure battery was not in the circuit I was getting 13.55V at the main battery but 14.2V at the alternator. I cleaned up the earths in the engine bay (one was particularly corroded so I dremeled back to shiny metal and replaced the nut and bolt), and now I get around 14.0V at the main battery.

So that's given me a bit more margin to play with in setting up the smartcom relay. I've now set it to come on at 13.5V and go off at 13.0V (you can't choose the thresholds separately - one adjuster screw affects both together). It's now a LOT more responsive - comes on almost as soon as the engine is running and goes off very soon when it's stopped too. Even with the leisure battery back in the circuit I'm still getting about 13.7V.

Much happier now - thanks for the advice folks.
Chris

[ghost123uk]

So next is to test that your leisure battery is OK. Do this by charging it, preferably on a home / domestic charger, for around 12 hours, then leave it for a day, not connected to anything and then measure the voltage. it should read between 12.6 (worst) to 12.8. If it drops much below that 12.6 figure, it is not in good condition.

[California Dreamin]

Still sounds like the leisure is dragging things down a bit and to be honest, I like to charge my leisure battery 'Off Van' so to speak, separately and on a regular basis, to guarantee that it's 100% charged. Thats regardless of your current situation.

Martin

[CJH]

So next is to test that your leisure battery is OK. Do this by charging it, preferably on a home / domestic charger, for around 12 hours, then leave it for a day, not connected to anything and then measure the voltage. it should read between 12.6 (worst) to 12.8. If it drops much below that 12.6 figure, it is not in good condition.

Still sounds like the leisure is dragging things down a bit and to be honest, I like to charge my leisure battery 'Off Van' so to speak, separately and on a regular basis, to guarantee that it's 100% charged. Thats regardless of your current situation.

I'm pretty sure my leisure battery is in good shape - it's only about six weeks old, although admittedly I did flatten it once while away on my hols. I've just checked the voltage with it having stood for several days, with only occasional engine starts to check everything still works after 'fixing' something else (fuel lines this evening). The voltage 'at rest' was 12.85 to 12.9, so it seems OK. I think it's inevitable that it'll drag the combined battery voltage down a bit, since it's slightly bigger than the main battery (80AH vs 70AH), and it'll usually be more discharged than the main battery. But at the moment I'm still measuring 13.7V across the combined battery while the engine's idling. As each battery reaches full charge after a long run I'm quite confident that charging voltage will rise a bit.

You're not perhaps confusing me with Adam, the OP, who's thread I've shamelessly hijacked, are you?

[Ads1987]

Thanks for the info guys, I've been reading the split charge wiki too just to try and understand it all.

Before I go and spent lots of time re wiring things; I'm currently running my amp and external spotlights from my leisure battery just because its a bit tidier and the wiring is concealed more.
Question is would connecting the amp/lights to the vehicle battery actually change the voltage controlling the smartcom?
I have adjusted the screw and the relay either constantly clicks with the engine running or I think it seems to be open for a long time with the engine off as its almost flattening my starter battery. I'm Going to test both batteries properly as both are looking a bit ropey, but the way I understand it is the smartcom just links the two batteries together so even if I do wire my amp and spots to the starter they will still bring the total voltage down and mess about with the relay?

Hopefully this makes sense,

Thanks,

Adam.

[ghost123uk]

You can wire them to either, it doesn't make a difference when the engine is running as, like you say, both batteries are as one.

E D I T = spelling

[CJH]

I think wiring the spot lights to the starter battery would change the behaviour of the smartcom relay though. Currently, the clicking 'on-off' behaviour is probably caused by the *change* in voltage when the starter battery is connected to the leisure battery+spots. That change in voltage drags the combined voltage down below the 'relay open' threshold, so it disconnects, and then you get a voltage change in the other direction. If you were to connect the spots to the starter battery, although it might take longer for the smartcom's 'relay closed' threshold to be reached, there would be less of a change when the leisure battery connects, so you might avoid the clicking (assuming you adjust the thresholds to suit this setup). One potential issue might be that you'll still get the clicking if you turn the spots on after the relay has closed, since they will still drop the voltage and it might be enough of a drop to open the relay again.

Either way, it does sound as though one or both of your batteries is a bit past it. If the leisure battery can flatten the starter battery through the smartcom relay, then a) your thresholds are set too low, and b) both your batteries need a really good charge at the very least. Do you have a meter to check the battery voltages after they've been resting for an hour or two?

[California Dreamin]

You are making it sound like the spots are a massive consumer when at 60watts a piece they are only drawing 10 amps. When you consider most T25's have a 65amp alternator that measly 10amps is easily covered and replaced by a 14 volt regulated supply of MUCH HIGHER value.

Martin

[Ads1987]

I'm going to buy a multi meter to help test the systems soon as I need to see the condition of the batteries, was mainly just trying to figure out if it was worth changing the wiring or not really.

I'm quite tempted to just go for a normal split charge relay set up, that way I assume the batteries will just charge when the alternator is running and hopefully avoid these issues anyway.

Of course the main problem seems to be the condition of the batteries either way

[dbz864]

By adjusting the relay the wrong way you will leave the supply to the fridge on(presuming the fridge is switched on)this will flatten your battery till it reaches a set level(the level is altered by adjusting the relay).New tranists are a problem for these relays as there batteries for some reason over charge more than any/most other vehicle.

[California Dreamin]

By adjusting the relay the wrong way you will leave the supply to the fridge on (presuming the fridge is switched on) this will flatten your battery till it reaches a set level(the level is altered by adjusting the relay).New tranists are a problem for these relays as there batteries for some reason over charge more than any/most other vehicle.

I'm not sure how you think the fridge is wired because your explanation just doesn't make sense in the context of a standard battery to battery split charge setup....sorry.
These relays are always set well above battery voltage.


Martin

[dbz864]

The relay is smartcom which has an output for a fridge,so when the ing is switched off there is no power going to the fridge so the battery wont flatten if you leave the fridge on. Same as most/all split charge/fridge relays. However the relay , has an adjusting screw, if the battery has a higher voltage than normal(normal to what the relays are set by)the fridge output will remain positive till the battery drops its charge to the set level,once at that level the relay will switch the power off to the fridge.This level can be adjusted by the said screw.The guy who sells these relays explained to me that they often have trouble with modern ford transits,for some reason they charge at higher levels. Seemed odd to me, but that's what he said to me. I tried it with a simple voltmeter and it worked. The seller of these sets them to a standard level before mailing them out. Ive proberly not explained it very good and im not pretending to be a elec expert as im not.