redarc manager 30


Well-known member
the Victron Orion is their DC to DC charger, the size of that would be decided by whats appropriate for your wiring and length, most OEM wiring would be around 10-15A I suspect.. consult your manufacturer and see if they have a max output rating for the trailer plug 12v+ source and stay under that.. If you used a redarc it would try to pull 30A over that wiring and you'd pop a fuse certainly.


New custom wiring runs are well worth getting good current flow from the alternator back to a trailer, bypassing any existing wiring / connectors.


Well-known member
depending on the battery chemistry yeah sometimes, I get a good 20A out of my fixed panel while driving and that seems fine for me.. I dont really need charge while driving but it is super nice to cook while driving, figured out how to secure a crockpot for road travel.. with LFP and no fixed panels on roof I think I'd invest in more power from the tow vehicle, just to get the most out of my engine runtimes.

my last trailer with lead batteries it ended up being pointless expense and effort, I upgraded all the wiring to the trailer but then only did a few days of 6-7h travel on a 2-3 week vacation, most days were moving camp a few hours down the trail/road.. didnt even bulk much.. ended up having to find shore power every few days when solar conditions were not cooperating cuz I didnt have a genset.. now if the house bank was in the tow vehicle its a whole new ball game, just puttering around sight-seeing is filling the bank when a trailer would be back at camp, likely shaded cuz your not there to move the panel over a few feet.


Well-known member
blusea, I dunno nothing about AgCa chemistry but LFP will gladly take more current than is healthy for it, with a LFP bank and an alternator source you want a DC-DC just to regulate the max current.. they will suck up far more amps than is healthy for both the battery and the alternator.. most alternators are not designed to output 100% duty cycle continously for hours.


I have dual 220amp alternators spring not overly concerned but definitely see the value in regulating it. Especially to avoid fire.

what side of the cable does the Orion go on? Starter battery side in truck? Or LFP side in trailer?


Well-known member
it goes inbetween em.. close to the battery as its charging so it can boost any losses along the way.


thanks for the input. after lots and lots of research i went ahead and ordered the victron smart mppt 100/30, and the victron ip67, but the smart orion-tr 12/12-25 is pretty much out of stock everywhere. rumor has it they pulled them all back in to fix a defect and it may be next month before we see any.

i also ordered the smartshunt.

per a simplified version of the diagram i linked above, my plan is to have a positive battery bus that connects to the main positive bus with a manual switch and the smartshunt and fuses off the main bus. And also connect to my 3 chargers via breakers. then i'd have a negative bus that connects to everything. I still have to figure out the inverter.
routing cables around the camper and building a panel is going to be challenging.


Expedition Leader
taliv I'd keep the manual switches as a way of cutting power / isolating subsystems when you need to work on things, but I'd strongly encourage some sort of solenoid or 'smart' connection which will feed power to all your added stuff automatically when the vehicle is running. All that alternator generation for nothing if the human forgets to connect a breaker.

/and frankly it's another topic / system design that I cannot fathom. All that money for high end gear and then staying too-small on the wire gauge and having to even give an excrement about 'voltage drop'. And likewise having all that alternator amperage available and then deliberately constricting it with a 30A chokepoint. Doesn't make any sense to me. Why even have dual 200A+ alternators if you are going to put a 30A restriction between them and your target battery? Seems completely bolloxed to me to deliberately design your power flow that way. Getting a fast bulk charge into your batteries during 'overlanding' would be more important that fetishizing that nth degree of 14.6-14.7v to a costlier battery, would it not? They don't need that bit of charging finesse every day. Seems like a very poor tradeoff in regular usage.

/there's a bad mix of fixed off-grid solar optimization with vehicle-borne system practices, which are working at cross-purposes. System designs are being predicated on marketing and fads and new gadget trends and not on more sensible overall design goals like 'getting the most power in the batteries in the least time'. A vehicle has a built-in DC charger capable of 60-200A. It doesn't make any sense to put anything in your design that deliberately reduces that power availability to just 30A - and do so in the name of 'adding power capacity to the vehicle'. If you choose a battery tech that is incompatible with your vehicle's native power charging ability - like adding AGM or some lithium variant that has to have 14.6-14.7V applied to it - and you are already incorporating solar - then arrange your system to put max alternator power to your batteries when available, and put the charge controller on the solar as a parallel / alternate power source. Instead of interrupting / blocking the majority of the alternator power. That way you get the best of both, the max bulk charge from your alternator - 'free' - and the fine-tuned / float from your solar controller.
And when people are spending several hundred to thousands of dollars on all these other devices, well, running some thicker wire and heavier duty connectors is a paltry additional cost but has a potentially (no pun intended) greater value for the money spent.
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i created a new thread since everyone here talked me out of the redarc. Thread title starts with victron.

Where did all of you order your Victron equipment from?
Mix of places. Much of it isn’t in stock. On wait lists for the Orion in particular. But mostly inverter supply and inverter service center. I’d order from both again.

The dual alternators was an option from factory. I ordered my truck instead of picking one from the lot. Basically I could get one or two alternators and I chose two because I tend to use a lot of juice running air compressors and all sorts of other stuff. And because it was cheap option.

I spent a good bit of money to run a large cable back to the trailer When I had the national Luna solenoid installed. It was 3 years ago so I don’t recall the gauge. But then I go through an Anderson connected to another cable to get to back of trailer to where the batteries are. So it’s just a really long run. Most people won’t have 30+ feet of wire but I do. Not something I can really shorten. I don’t really need the solenoid that much as when I’m using the trailer batteries the truck is usually disconnected. It’s not permanently connected like most systems in a taco or sprinter would be. And reality is, it’s been charging the 3x 102ah lead batteries pretty dang well for years. But as I switch to lifepo I need higher voltage.

I kinda went overboard on cables inside the trailer as I’m rewiring. But that one cable I can’t fix easily because it’s heavily waterproofed and routed through the frame. Believe me if I didn’t have to drill out and replace rivets and waterproofing I would put an enormous cable in lol. I may anyways.

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