Feedback please on my new leisure battery wiring diagram

[Velosaurus]

Hi, I would be very grateful for feedback on my proposed refresh of the leisure battery system on my 2013 T5.1. Current set up is an 8 year old Travelvolts SCR with the addition of a 150w Solar panel on pop top. Van is currently used for weekends and weeks away using hookup. I am planning to spend more time in the Hebridean Islands & Orkney this year so need better off grid power.

I am planning initially to fit a Fogstar 105A Drift LB, a Victron Orion XS 50A DC-DC set at 30-35 Amps & a Victron 100/20 MPPT, under the passenger seat. My load calcs suggest this will give me 2-3 days off grid (fridge, lights & sockets), with no engine use. I looked at the 230ah Seatbase battery, but it stretches my budget and with my seat swivel I would need to remove the foam under the base and even then it would be tight. If a 105a Lithium Battery & 300w of Solar isnt enough I could fit another 105a battery under/behind the drivers seat.

My mains hook up is under the bonnet, I will also fit two RCBO breakers and my existing Victron 12/7 battery charger by the engine battery. I will also get an underslung diesel heater fitted (after I have the van undersealed). I'd like the design to allow the addition of a folding Solar Panel & small inverter run a Remoska later this year.

Any feedback on the (revised) Drawio diagram below would be brilliant.

Thanks Andy

 

[Velosaurus]

Pic of van for reference

 

[Sim60]

I think 200A fuse is too large for 25mm2 cable from the leisure battery. 150A fuse?

Simon

 

[oldiebut goodie]

Wire the heater and fridge direct to the battery ( with fuses ), I hate to see resistance points added as both these items are sensitive to voltage drop. You have 3 points there - cut them down to 1.

 

[Dellmassive]

Looking good so far....

 

[Velosaurus]

I think 200A fuse is too large for 25mm2 cable from the leisure battery. 150A fuse?

Simon

Thanks. you are right the 25mm2 is only rated at 170A unenclosed so a 150 would be better. There is a 150A in the Maxi/Midi Busbar as well.

 

[TallPaul_S]

Looking good, my fridge is connected to my secondary fuse box and I've had no issues, so long as you use the correct sized wire and don't have a really long cable run you're good.

2 additions I'd make:

Add a Victron smart shunt. The Fogstar BMS is ok but it's not very accurate and cannot see any loads or draws under 1a so can very easily get completely out of sync. The Victron shunt will be 99.999% accurate. And you'll also have everything in the one app. Oh and the shunt will read both your SB and LB voltages.

Add an Ablemail amt 12-2. It's literally 3 wires, one to the fuse nearest the Orion on the SB cable run, then as you have the 100/20 MPPT I'd suggest using the load output on that for the other 2 connections, this will mean no extra fuses need in your fuse boxes, and you can turn off this if needed.

 

[Velosaurus]

Wire the heater and fridge direct to the battery ( with fuses ), I hate to see resistance points added as both these items are sensitive to voltage drop. You have 3 points there - cut them down to 1.

Thankyou. I have amended this so that the fridge goes back to the main busbar (Martyn did advise the same when I installed the travelvolts kit). I want to be able to fully isolate the Leisure battery so it needs to be downstream of the main isolater switch. I need to speak to the heater installer in Dumfries and see what they want to do as there may be warranty implications.

 

[Velosaurus]

Looking good, my fridge is connected to my secondary fuse box and I've had no issues, so long as you use the correct sized wire and don't have a really long cable run you're good.

2 additions I'd make:

Add a Victron smart shunt. The Fogstar BMS is ok but it's not very accurate and cannot see any loads or draws under 1a so can very easily get completely out of sync. The Victron shunt will be 99.999% accurate. And you'll also have everything in the one app. Oh and the shunt will read both your SB and LB voltages.

Add an Ablemail amt 12-2. It's literally 3 wires, one to the fuse nearest the Orion on the SB cable run, then as you have the 100/20 MPPT I'd suggest using the load output on that for the other 2 connections, this will mean no extra fuses need in your fuse boxes, and you can turn off this if needed.

Thanks Paul. Didnt realise that the Smartshunt gives more accurate feedback and more importantly starter battery status, although I need to read up and get my head around how that works. For now I have added it and plan to fit it across the LB negative out.

The Ablemail is already on my future mods list. The van does sit idle as I do all my local journeys on an e-bike. I try and take the van out once a week for an hour. I moved to Dumfries & Galloway from Berkshire a couple of years ago and its so much moister up here that everything on the van is rusting in front of my eyes!

 

[TallPaul_S]

Yeah I don't use my van much, sometimes only once every 3 weeks - and the Ablemail happily keeps the SB at 12.3v all day/week/month long.

 

[Anakin]

Sorry for the interruption of your thread, but hopefully it’s useful. I’m in the planning phase of a rooftop solar panel and saw your diagram. I wasn’t planning on having a solar isolator and also saw this link that says not to have one. Do people think they are necessary?

Isolators for Solar Panels

Isolators for Solar Panels - an article by 12 Volt Planet. A product we get asked for a lot is 2-pole isolators for use with solar panels .. we break down the myths behind these switches and explain why they may do more harm than good

www.12voltplanet.co.uk

 

[TallPaul_S]

You don't need one, and they are correct in that they add another connection point.

But (I have one) they're good to have for a couple of reasons:

1) MPPT's don't like having solar power incoming with no battery to charge, in fact you can damage the controller this way. So if you have a master system cut off which disconnects your battery from ALL inputs and outputs, you need to also isolate the solar from the MPPT.

2) if you want to do a full discharge of your battery by turning off solar, or if you need to turn it off for some other reason, it's much easier to do this by flipping a switch than by unbolting a midi fuse.

 

[Velosaurus]

Sorry for the interruption of your thread, but hopefully it’s useful. I’m in the planning phase of a rooftop solar panel and saw your diagram. I wasn’t planning on having a solar isolator and also saw this link that says not to have one. Do people think they are necessary?

Isolators for Solar Panels

Isolators for Solar Panels - an article by 12 Volt Planet. A product we get asked for a lot is 2-pole isolators for use with solar panels .. we break down the myths behind these switches and explain why they may do more harm than good

www.12voltplanet.co.uk

I dont have one fitted currently, just a fuse across the positive, but plan to fit one, for the reasons Paul says, so I can isolate the panel if doing any work, disconnect from the MPPT if I am disconnecting the leisure battery, or just if I am doing any testing. The one you have linked to is a bit of a brick. I need to do more research on options. I have seen a mini version like this Solar PV Switch DC 40 Amp 12-500V Breaker Enclosure which is slightly smaller, but will research other options.

Another thing I would do differently is I Sikaflex glued my flexi panel on. Present me would tell past me not to because if it fails I will need to remove it and also I can get a 300w panel now for the price I paid for my 150W, 3 years ago. I think i was worried about vehicle height as well when I fitted it. I would look at roof bars on the pop top and a rigid panel next time. Either that or just glue the bigger panel on top of the old one but then at some point I will have two to remove

For now I will just get the install and other stuff I am planning (furniture changes, move the gas locker) whilst I mull it over. If the 150W comes off intact could store in poptop and use as a portable panel with frame & use the spare 75/15 MPPT I have. I might be able to cheese wire cut it off and will try a debonding agent like DeBond Marine Formula on a Sikaflex sample.

 

[firedrake]

Hi, Just wondering what type of switch would you use to switch lights etc on and off? don't see one, and is there anything to look for in a switch?

 

[Velosaurus]

Hi, Just wondering what type of switch would you use to switch lights etc on and off? don't see one, and is there anything to look for in a switch?

I use CBE Switches at the moment like these with a surround fitted. I have one double switch at the front on the top of the B Pillar by the sliding door that controls the sliding door footwell light and front pair of recessed LEDs and one double switch towards the rear which controls the middle and rear pairs of recessed LEDs.
I have a side conversion and pop top fitted. When the pop top was fitted an EVO DESIGNS shelf above the cooker/sink with a touch sensitive LED strip came out. I intend to put this back as part of this work.

I like the CBE switches as they dont have any LED indicator lights which are annoying when sleeping in the van.