Jayco Flamingo - Understanding how the 240/12v system works

Stinkys · Member

Jayco Flamingo - Understanding how the 240/12v system works

Possum3 · Guru

Welcome to the Forum Stinkys, I won't comment on the electricals on the Jayco camper other than to say "ensure your wiring is heavy enough to handle you proposed upgrade".

Enjoy your camper and have fun out there.

TimTim · Senior Member

Hi Stinkys,

Welcome aboard.

Firstly it is good if you can list the make and model of things like your size of battery bank, battery charger and solar controller etc.

When you say significant voltage drop overnight can you give us the voltages that you are seeing. LiFePO4 can show up to 14.6 fully charged and then drop to about 13.4 to 13.6. They are still fully charged. What make of batteries do you have as some have the BMS set to only be charged to 80% of their capacity.

Whether the battery isolator switch should switched on or off would depend where it is located and in which circuit. Simple test, plug in the 240V and flick the swtich. If no charge either way, providing the battery isnt full, then further investigation is needed.

Tim

Stinkys · Member

Thanks for the prompt replies!

To clarify on the setup further:

2 x 200W panels on the roof. Replaced maybe 300W worth of panels... not sure exactly as I lost them somewhere on the Bruce Hwy when bringing the trailer home Not ideal but had no idea it happened.
The MPPT is a factory Voltech ISC3040. I have rejigged the bulk to 14.6V and float to 13.8V currently. I think float should be lower around 13.0V but there was nothing specific from battery manufacturer around this.
I had 2 x AGM batteries in previously, have since replaced with 1 x 135AH Mobi LiFePO4 battery and intend to drop another one in shortly. The battery has a BMS with digital readout which is where I am seeing the drop from say 74% last night to 69% this morning. So far I have not managed to get the battery back to 100% (according to the BMS) because I haven't been able to get enough charge in. The camper is currently in the shade.

I have not managed to dissect the circuit yet so hard to comment. But the wiring has not changed from factory, I have just replaced existing components.

I think you are right, I'll just have to test it further. The clue is in the name - battery isolator. I have so far been focusing on leaving the battery off, assuming that it will charge even though it's connected to mains.

TimTim · Senior Member

Ok firstly, ignore the battery digital readout. BMSs are known not to be accurate in determining the state of charge. It will be accurate at 0% am

and 100%. If knowing how much charge is left in your battery is critical to you then get yourself a shunt. Some ppl use this brand but plenty of others out there.

https://www.aliexpress.com/item/1005005293126063.html

Many people float between 13.4V and 13.8 for LiFePO4.

First thing is to get your batteries charged back to 100% and see what happens from there and also test your 240V charging with isolator in both positions.

Tim

Rod Mac · Veteran Member

Hi, Just check the factory charger is actually working, I had the factory charger in a Jayco Eagle drop it's bundle sitting at home, tripped the house circuit breaker and killed the near new battery!

I got an auto elec to separate the 12v/240v and put in a decent Ctec charger as he said at the time the Jayco one was only average quality.

TimTim · Senior Member

Yeah, just a thought as Stinkys may have a Setec or Centurion installed and neither of those are capable of charging the battery efficiently. Well I know the Centurion isnt. If he has then best bet would be to install a power point near the batteries if there isnt one and connect a decent charger to the batteries permanently.

Tim

Stinkys · Member

Interesting you say that, Rod, as my circuit is tripping right now. Thought rain in Brisbane has got in somewhere it shouldnt. Will disconnect the battery i think until i get this figured out. Any idea what youre original Jayco charger was?

Stinkys · Member

Its a Voltech ISC3040 that I have right now.

TimTim · Senior Member

That is your solar controller not your 240V charger.

TimTim · Senior Member

You should have a power converter installed somewhere that steps down the 240V when connected to mains to run the 12V system. It will be under a bed or a storage area and should be easy to find. Centurion and Setec where two brands of converter I know Jayco installed.

kgarnett · Senior Member

Stinkys wrote:
The clue is in the name - battery isolator.

If the battery isolator is doing its job, then the battery is isolated and there can be no current in or out of the battery.

Stinkys · Member

Right, found it. I thought that was just a fuse box biggrin Setec ST20-III which according to the manual has a DC output of 13.65V 20A. So not enough juice to bulk charge the battery.

Does anyone have any cost-effective recommendations for replacing this unit? Thanks again for letting me pick your brain.

-- Edited by Stinkys on Wednesday 22nd of November 2023 09:54:53 AM

valiant81 · Senior Member

Stinkys wrote:
Right, found it. I thought that was just a fuse box Setec ST20-III which according to the manual has a DC output of 13.65V 20A. So not enough juice to bulk charge the battery.

Does anyone have any cost-effective recommendations for replacing this unit? Thanks again for letting me pick your brain.

-- Edited by Stinkys on Wednesday 22nd of November 2023 09:54:53 AM

Hi Stinks, My own Jayco pop top caravan also has the same battery charger as you and while it deliver 20Amps into a load ( your camper ) as a battery charger it will only charge at a float level and off hand is 800 Ma ( 0.8 Amps ) I had the same problem with my set up and with my own house batteries going flat after a couple of days. I crack the ****s and disconnected the selec charger from the mains ( i still use the selec as a fuse pannel and left that part of the wiring alone ) and i now use a Victron 12 volt 30 Amp smart charger, this is also blue tooth capable and one reason why i chose Victron . This was a game changer and has made all the difference to our free camping. I have also after a while bought a 500 Amp smart shunt ( again Victron and blue tooth capable ) That and anothe victron solar controller, blue toothed of course ( 75/15 ) as i on lt have 240 watts of solar on my pop top roof. All this feeds 2 x 220 AH agm batteries. I liked the idear of the blue tooth arangement on the victron equipment. I can look at what the battery voltage is , what the current is goin into or out of the house batteries, what the solar input is or what the Victron smart charger is supplying or has shut down as the batteries are fully charged.

We have free camped for up to 2 weeks free camping and on the 13 day my system shut down due to a few days of no solar input ( rain and heavey clouds ). I have bought a small generater that i plug into the caravan and this wakes up the smart charger and after a few hours my house batteries are back up to full capacity useing the smart charger.

My caravan is basic lt all 12 volts, and i do run 2 x 40 Ltr compressor fridges, led lighting inside our caravan and outside, sat tv, diesel heater, a small 240volt inverter 300 watts ( electric shaver or a desk fan ).

-- Edited by valiant81 on Wednesday 22nd of November 2023 10:35:47 AM

TimTim · Senior Member

Stinkys wrote:
Right, found it. I thought that was just a fuse box Setec ST20-III which according to the manual has a DC output of 13.65V 20A. So not enough juice to bulk charge the battery.

Does anyone have any cost-effective recommendations for replacing this unit? Thanks again for letting me pick your brain.

-- Edited by Stinkys on Wednesday 22nd of November 2023 09:54:53 AM

Ok firstly you need to know if the Setec is tripping the circuit breaker. Unplug the Setec from the 240V system. Reset you circuit breaker and then plug the van into 240V to see if the circuit breaker trips again. If it doesnt then it is not the Setec causing the issue.

Do you have a fridge that works off 240V as well as that will need to also be disconnected.

Tim

Stinkys · Member

Good idea, Tim. I will try that this evening. Yes I have a 3-way fridge that is currently set to 240V and was working OK over the weekend. I will try unplugging everything and then gradually turn things on until I find what is tripping the circuit.

If I do need to change the Setec out then looks like a Victron IP22 12/20 or 12/30 should do the trick?

Valiant, I think I can see what you mean by dropping in the Victron. Where did you wire the Victron 12V output in to the Setec (I figure it would be via Aux In)?

TimTim · Senior Member

Stinkys wrote:
Good idea, Tim. I will try that this evening. Yes I have a 3-way fridge that is currently set to 240V and was working OK over the weekend. I will try unplugging everything and then gradually turn things on until I find what is tripping the circuit.

If I do need to change the Setec out then looks like a Victron IP22 12/20 or 12/30 should do the trick?

Valiant, I think I can see what you mean by dropping in the Victron. Where did you wire the Victron 12V output in to the Setec (I figure it would be via Aux In)?

Ok if your fridge was working over the weekend on 240V then sounds like you have an intermittent fault somewhere and hopefully your Setec is ok.

The Victron charger does not replace the whole of the Setec unit. It merely replaces the charging function of the Setec. Your Setec remains connected to the battery to supply 12V power when off grid. If the Setec is working that is. The Victron charger is not connected to the Setec. It is plugged into a GPO as stated below.

Your Setec is a power converter stepping down the 240V to 12V and providing power to all the 12V circuits when connected to 240V. As you can see it is also the fuse panel for all the circuits.

As I see it your options are and someone please correct me if Im wrong:-

1. If the Setec is working, connect your battery to the battery output as on Page 2 of your manual. Buy yourself the Victron charger and plug that in to a GPO near the batteries and wired to the batteries. That way when connected to 240V your charger will charge the batteries. This is what Valiant has done.

2. If the Setec is not working you will need to replace it with a similar power supply but they are expensive. The alternative is to disconnect the Setec from the 240V circuit. Install a fuse panel to all your 12V circuits and connect that directly to your batteries. Also connect your battery charger as above.

Tim

-- Edited by TimTim on Wednesday 22nd of November 2023 03:44:57 PM