A few SETEC questions

[Archie]

Hi guys, new to the site although I've been a long time follower so bear with me.
I'm the proud owner of a 2012 16.49.4 with one (so far) small problem. I've already had one Setec ST20 II replaced under warranty just over a month ago after only one trip away. We took the van out for it's second outing last week and the replacement unit blew as well. It supplies power on 240 volts but there is nothing from the 12 volt end.
Having read everything I can find on these units I've got a few questions I was hoping someone can answer:
Tow vehicle is a 2013 Mazda BT50. Obviously this has a variable voltage alternator so I was wondering if the Setecs work with those.

Secondly, the Setec manual recommends a 20 amp fuse between aux power supply (vehicle alternator) and the unit. There doesn't appear to be one fitted, could this be the problem.

Finally, if I have inadvertently left the battery turned on when the unit is also running 240 volts, can this damage the Setec.

I'm a bit worried Jayco may baulk at replacing a second unit under warranty and look to blame the tow vehicle or user stupidity.

Thanks
Archie

 

[Mike7]

Gday Archie.

Welcome to the fold, you are gonna luv the van. You will do no damage if leaving the battery turned on when the unit is receiving 240V power, in fact unless you have the battery turned on the Setec will not be able to charge the battery. When parked at home you can leave 240v connected to the van permanently with the battery turned on so the setec can keep the batteries in top shape. Think of the battery on/off switch as an isolator between the Setec and the battery. You can do the same at a caravan park to ensure the batteries are being charged. If you are connected to 240V and you have the battery turned off the vans 12v services are still available as the setec has a 12v transformer that powers the services, it doesnt actually use the battery until you disconnect 240v. Hope that makes sense.

Need some more info with the connection between your car and the Setec, do you have power going from your car to the Aux "in" on the Setec unit? If you do be aware that the max voltage for the aux-in is 14.8V as per the manual. You will damage components if you exceed 14.8V.

If you need any info on how guys charge the batteries in the van from the car while driving let us know, we can open that can of worms which is alway fun.

Let us know how you have the Setec connected to the BT50 so we can be of more assistance.

Cheers
Mike

 

[Capt. Gadget]

I think you do need to leave the battery switch on when connected to 240 to be able to charge it. A mate of mine with a 18 footer had a setec replaced and believed it was a problem with his alternator which he also replaced at the same time that had caused the damage, there is something in the manual that says you shouldn't charge with more than 14.8v or it can damage the charger maybe just check what the voltage is that is coming from your vehicle, also maybe check a few connections on the 12v side too as Jayco are notorious for being slack when it comes to crimping a wire !

 

[Archie]

Thanks for the prompt replies guys. Should have mentioned the setup a bit better. I'm running a 7 pin plug with separate 6mm B&S wiring to a 50 amp Anderson Plug. The Anderson Plug powers the Setec and Fridge. There is a cutoff wired to the ignition so it disconnects when not running. The local Jayco repair guy only fitted the replacement Setec unit two weeks ago so I don't want to jeopardise any warranty claim by pulling the facia off and checking contacts. It's booked in for Monday so they can have a look.

Mike, the power runs from Anderson direct to the Aux +ve in the Setec, no fuses in line or anything.

I'm more worried about what voltage the alternator might be pumping into the Setec. I know quite a few of you have BT-50s, any problems I should know about? I've only towed with the BT twice and the Setec has failed both times.

 

[cruza driver]

I've never had any issues @Archie but I haven't wired an Anderson up in the BT yet, maybe this week :violin:. It does sound odd though and the others have probably already answered your questions.

 

[Archie]

Thanks Cruza. Eventually I'll go to a Redarc BCDC low voltage charger cos I'm not that impressed with the Setec anyway.

 

[cruza driver]

No worries mate, if you have time do a thread about your BT, by looking at your avatar it looks good mate

 

[Mike7]

Gday Archie,

If you havent driven the car for a couple of days connect a multimeter to the battery terminals and have someone start the car and have a look at the volts. As the battery will be at its "flattest" at the start you might get an idea of the initial volts coming out of your alternator. Or call Mazda and ask em what the alternator operating voltage range is to see if there is any possibility of it being higher than 14.8v.. Only caveat is with todays cars with the amount of electronic wizardry going on under the bonnet its hard to diagnose anything unless you plug the car into a computer. It does seem strange that the setec has blown both times.

I dont think there is a whole lot to be gained by connecting the Aux to the car as when the setec receives power thru the aux in it is only capable of trickle charging the batteries. The dc-dc you mentioned is the better option.

Its interesting to note that with my setup from the jayco factory the setec is never going to be able to charge my AGM batteries as they need to get up to 14.7v, the setec can boost for a short period to 14.05v. I have a Bm-1 battery monitor which was showing the batteries getting to about 83% capacity.It was only when I switched to a Ctek charger that I got the batts up to 100%.

Anyway enough rambling on from me.

Cheers
Mike

 

[achjimmy]

Hey Guys

Archie you mentioned 6mm B&S? It's either 6mm auto (normal Jayco internal wire & approx 4.5mm2) 6mm2 or 6B&S (13mm2) confusing hey

When I ordered our van I wanted an Anderson to the fridge in the heavy flex they use on the big vans. I got the twin batteries wired in 6mm Auto to an Anderson? Jayco had bypassed the setec with this wiring and wired it direct to Batt 1 through a fuse (that happened to be blown when I checked). I would suggest do this and having your 12v supply independent of the setec. I have had no known problems in 18 mths doing this. Our setec is the 35 model and every time I hook the Projecta 2500 seven stage on to check the batteries it almost immediately goes to float, which tells me all is okay or that the $250 Projecta can't do better, the Projecta also has the ability to select "type of battery" unlike many chargers.

Be cognitive of a couple of things in the above comments. A DC DC. Charger is great but it doesn't charge anywhere near the rate of an alternator so if you are only traveling a few hours in a day the charge will not necessarily get there. Also be aware that feeding the high drawing fridge off the house batteries are doing them no good in getting charge. I choose to wire the fridge separately to the start battery with a relay so that charging of my car aux and van batteries are separated I choose another Anderson for my reasons but you can get reasonably heavy 8b&s through the 12 pin van plugs.

 

[Archie]

Morning Jimmy,

Wiring on the BT50 is 6B&S to the Anderson plug. Wiring past that on the van is standard Jayco. The fridge doesn't run from the house battery or via the Setec. As far as I'm aware, the Anderson plug splits off to the Setec (unfused) and also goes back to the fridge via a separate wire if that makes sense. That takes place in the "birds nest" under the van. That leads me to wonder if the fridge draws more amps down that line than the Setec can handle. (Not sure if it works that way but it does in my simple mind).

My plan is to fit a 25 amp DC DC charger direct to the battery. I'm told that will charge faster than a VARIABLE VOLTAGE alternator, which cuts in and out depending on other conditions. This will do as you suggest and isolate the Setec from 12 volt "in".

Clear as mud and hence my confusion......

 

[cruza driver]

@Archie I spoke to @Moto Moto today and he has a new BT with an Anderson plug and he has never had an issues and he has had his BT for 12 months which has seen plenty of towing duties with no issues.

Just thought I'd let you know mate

 

[achjimmy]

No worries Archie should work well. And easier than running two runs like I did other than it won't charge faster than alternator IMO. You can also replace alternator fuse with a diode fuse to the boost the voltage $45 and it charges every battery as they did before they came up with these stupid alternators.

It's worth noting I am told that dealerships are reporting a lot more batteries failing under warranty and just out in the last few years since these alternators have been released, so for $50 it's probably worth doing?

 

[Archie]

Thanks guys, quality advice all round. Just goes to show the value of this site. I'll update with the outcome when I find out.

Cheers
Arch

 

[macca]

This may be stupid, but I have wondered if instead of wiring van to car for charging whilst driving, what about an extra solar panel or two. I know it wont run your fridge whilst driving but for normal trips would it be OK. Solar panels are so cheap now you could have your van roof covered in the things.


Geoff

 

[Capt. Gadget]

This may be stupid, but I have wondered if instead of wiring van to car for charging whilst driving, what about an extra solar panel or two. I know it wont run your fridge whilst driving but for normal trips would it be OK. Solar panels are so cheap now you could have your van roof covered in the things.


Geoff

Mine is mounted to the roof of the van and connected direct to the Batteries through a Ctek 250 dual so it charges while driving, at the moment the rest of the system is still connected as normal so the Fridge gets it power from the 12 pin plug but when i get a cup of motivation I will hook the fridge up via anderson plug from the Tug

 

[achjimmy]

This may be stupid, but I have wondered if instead of wiring van to car for charging whilst driving, what about an extra solar panel or two. I know it wont run your fridge whilst driving but for normal trips would it be OK. Solar panels are so cheap now you could have your van roof covered in the things.


Geoff

I think that's the best time for the solar. I usually end up in shade so the solar is of marginal value at rest but 4-7 hours on the highway is perfect. Although as above with the alternator charging I am not sure how much the solar can add?

 

[macca]

To simplify my query.

Are you just better having a decent solar system and no connection to the car at all?

The way cars are going with sophisticated electric systems, it seems risky to be adding 12v things to them.

 

[Capt. Gadget]

To simplify my query.

Are you just better having a decent solar system and no connection to the car at all?

The way cars are going with sophisticated electric systems, it seems risky to be adding 12v things to them.

It's a nice thought but cloudy days and power hungry 3 way fridges might not be a good mix

 

[Brad]

I have 2 solar panels on the roof of the van and without taking a good look, I reacon another one would not fit if you take in the antenna, vents and sunroofs.

 

[macca]

I have 2 solar panels on the roof of the van and without taking a good look, I reacon another one would not fit if you take in the antenna, vents and sunroofs.

2 flexi panels on hard lids!