Leisure electrics sanity check pls?

[TeeCeeJay]

Hi all,. After having read and absorbed as much of the advice on here that I can understand, I think I'm finally ready to build my leisure electrics system.
I'd be grateful if someone could cast an eye over my schematic to check my homework. Some of this is stuff we inherited when we bought the van and some of it yet to be installed/bought.

Most question marks are have I got the cable sizes right and are the fuses correctly placed and rated?

The dotted line from the Victron 75/15 is me wondering if that is how the 'load out' feature is supposed to be used so that the MPPT can be a smart switch between the loads and the battery? At one point I was thinking 'load out' was only for items that could be used when the solar was generating sparks but now realise that is a ridiculous idea.

At one point were also considering a Renogy DCC 50 or 30 to replace the Sterling BB1230 and the MPPT but budget means that will all wait for if we move to LiFePo battery next year.

DCDC - Sterling BB 1230
MPPT - Victron smart 75/15
Solare panel - Photonic Universe 200W
LB - Probat FLA 110 Ah
loads - the usual, Fridge, USBs, Lights, 12v

Van goes in a couple of weeks to get pop top and solar panel installed.
Thanks for all the advice I've already read and thanks in advance for any further comments on this plan.
TCJ

 

[Dellmassive]

You need to put the DC-DC charger at the leisure battery end. (Preferred location to limit volt drop)(not engine bay)

I'd go for a Renogy dc-dc to start over the sterling.

The load output on that 75/15 is limited to 15A, so take your 6Way fuse box direct from the battery.(15A won't be enough to runs all those loads)(or swap mppt to a larger unit)

Fit a low volt disconnect if you're worried about running the battery too low.

Look at fitting a battery monitor.

Defo look at fitting lithium up front. It's over £100 for an AGM and under £400 for lifepo4, so the price gap is reducing.

 

[Dellmassive]

More info....

Dellmassive’s "How I Done It" blogs.

-- Dellmassive`s -- "How I Done It" -- thread -- ************************************************** Dellmassive`s -- "how I Done It" -- Thread ************************************************** Kit List And Stuff -- How I Done It & What I Use --...

www.t6forum.com

...

 

[CJW]

If you follow @Dellmassive ‘s suggestion of replacing with a Renogy DC-DC + MPPT, then your diagram will simplify considerably.

Your positive supply to fuse box and fridge will go from LB positive, through fuses (like you’ve shown). No need to route solar directly to them as per your dotted lines. The Renogy will handle that.

Small point - some might disagree but I would put an isolator switch between the fridge fuse and the fridge. That way you can safely connect / disconnect the fridge without having to unhook the LB, and gain the certainty that the fridge is properly off in between camping trips.

Watch the current rating of that switch though - there are suitable switches around.

Your fuse ratings for lights seem quite high. Maybe worth recalculating those. You can buy as low as 1A fuses.

 

[TeeCeeJay]

Thanks @Dellmassive @CJW

If (when) I move the dc-dc to under the seat can the cable stay as 6mm? Or would it need beefing up? This is part of the install that we inherited on purchase along with the lead acid LB (which I realise is less than desirable).

The budget may need adjusting but I guess it's better to buy once and buy right than have doubts about your system.

I was reading in the Renogy online manual that if I did go for the DCC combined battery and MPPT version that it would have to be a 16mm cable to handle the up to 50A.

I'll take the feed to fuse box direct from battery. The dotted lines were because I wasn't sure which option to select. I'll also look at light fuses.

Thanks for advice.

 

[CJW]

Here’s a very useful cable sizing tool, half way down the page. You can make it specific to your situation. Cable length vs cross-sectional area of copper is the key relationship that means nobody can answer your question without knowing more.

Cable Size Calculator - Cable sizing and selection | 12 Volt Planet

Cable Size Calculator - Read our guide to selecting cable of the correct type and size for your automotive, marine or leisure wiring application. Auto and Marine Electrical Components from 12 Volt Planet

www.12voltplanet.co.uk

 

[Dellmassive]

More info.

Dellmassive’s "How I Done It" blogs.

-- Dellmassive`s -- "How I Done It" -- thread -- ************************************************** Dellmassive`s -- "how I Done It" -- Thread ************************************************** Kit List And Stuff -- How I Done It & What I Use --...

www.t6forum.com

.

 

[Eclipse Custom Vans]

You need to put the DC-DC charger at the leisure battery end. (Preferred location to limit volt drop)(not engine bay)

I'd go for a Renogy dc-dc to start over the sterling.

The load output on that 75/15 is limited to 15A, so take your 6Way fuse box direct from the battery.(15A won't be enough to runs all those loads)(or swap mppt to a larger unit)

Fit a low volt disconnect if you're worried about running the battery too low.

Look at fitting a battery monitor.

Defo look at fitting lithium up front. It's over £100 for an AGM and under £400 for lifepo4, so the price gap is reducing.

Agrre with all of this, also think about 230v AC charging.

 

[TeeCeeJay]

Thanks, we won't be using 230/240 hook up. we're only going to be weekend warriors / day trippers with an occaisional week away and have camped in a tent / car for 20 years without needing to use a microwave or hairdryer (the fridge will be a major luxury!) . Trying to fit everything under the driver seat too as we're not having traditional side unit cupboards to be able to stash all the electric gubbins in.

Agrre with all of this, also think about 230v AC charging.

 

[T6Jay]

I can't see it mentioned above, but if you replace the Sterling B2B and the Victron MPPT with a Renogy DCC50/30 you will reduce your choice of solar panels to those with a max 25VOC output, many 200W panels go over this VOC.

I have the Renogy DCC50S myself, with a 170W panel, the biggest I could find at the time with <25VOC. It's been big enough for us, so not an issue here.

 

[TeeCeeJay]

This is the solar panel we're getting fitted.

12V solar panels charging kits for caravans, motorhomes, boats, yachts, marine

12V solar panel solar charging kits for motorhome caravan boat campervan yacht marine off-grid

www.photonicuniverse.com

seriously considering a lifepo battery to make sure we can last through a cloudy weekend with the fridge running.

 

[Eclipse Custom Vans]

Thanks, we won't be using 230/240 hook up. we're only going to be weekend warriors / day trippers with an occaisional week away and have camped in a tent / car for 20 years without needing to use a microwave or hairdryer (the fridge will be a major luxury!) . Trying to fit everything under the driver seat too as we're not having traditional side unit cupboards to be able to stash all the electric gubbins in.

thats fine, we have retrospectively fitted many 230 systems to customers vehicles with 12v only. It may be worth runnin a few 230v cables just in case? Your van, your call of course.

 

[TeeCeeJay]

Thanks for the advice and comments. SWMBO has approved the new budget so looks like we will now ditch Sterling/Victron combo and join Team Renogy with a smart 100ah lithium batteries and the DCC50s with a BT dongle.

 

[Dellmassive]

Thanks for the advice and comments. SWMBO has approved the new budget so looks like we will now ditch Sterling/Victron combo and join Team Renogy with a smart 100ah lithium batteries and the DCC50s with a BT dongle.

Fwiw...

You can keep the Victron mppt and run it along side your new Renogy kit.

 

[Dellmassive]

And it you want a 6% discount on Renogy kit...

See me or @Deaky

I can get you a discount at Renogy United Kingdom

Hey, if you're ever looking for Renogy United Kingdom products, let me know and I can get you a discount at Renogy United Kingdom. Here's a coupon if you need one now:

renogyuk.refr.cc

.
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[TeeCeeJay]

And it you want a 6% discount on Renogy kit...

See me or @Deaky

rgr, thanks, I've already got a @Deaky 6% ready to go in my shopping cart! I remembered seeing it in his Signature block.

I can't afford to be getting both the Victron MPPT and the DCC50s, especially when the whole point of getting the DCC is that it has MPPT built in. I understand the likely reason for having both is so that the DCC can use the full 50A charge from the alternator without being restricted to only 25A when it is sharing the load with the solar but I'm happy with that for the simplicity of only having one box of tricks to worry about.

I've nearly finished reading all your How I done it blogs, some of it way more detailed and over my head than I'll ever need, but still a valuable source of intel for all users! Thanks in advance. Will let you know how we get on.