Need help planning for Solar and DC to DC

You definitely want a dedicated ground wire for the entire path from the truck engine compartment to the camper battery that is equal in gage to your large positive wire. Don’t rely on the chassis and camper mount conduction to serve as the negative path for battery charging current.
 
OK, thank you!

You guys would know better than I, does the 50A dc to dc charger get to hot to mount to a plywood shelf.

I can easily make it out of aluminum— I’m not sure what kind of an air gap is between the feet and the bottom of the charger. I’m assuming the heat sink is built into the top side. I haven’t found a real good side or bottom view of it on the web.

By the way, my 280A battery came yesterday….. I know I’m getting older but dang is that thing heavy😟
 
Here’s a link to the manual.

Manual - Orion XS 12/12-50A DC-DC battery charger

www.victronenergy.com www.victronenergy.com

It says mount to nonflammable surface, but also says the back plate will never exceed 90 degrees C (194F). I have my 30 amp Victron Orion (which has the same mount to a nonflammable surface caution) mounted to the painted plywood of my battery compartment. The paint does not show any evidence of heat.

There are probably far more of these in service mounted to plywood or fiberglass than to metal. I suspect by nonflammable Victron means not upholstered, carpeted, foamed, etc. Wood begins to turn brown and smoke around 400-450F.
 
Last edited:
Dadocut said:
.

If you draw a schematic we can accurately comment on what you;re doing. (one of these days I'll draw one for my system!)

Hope this helps
Click to expand...

Thank you Dadocut,

running my cables from the passenger side starter battery will be a breeze as I have already upgraded my battery lugs.

After rereading Jon R’s post, doing the simple math of battery AH divided by charged Amps, I have decided the 50A dc to dc charger is overkill for my limited power consumption on the 280 AH battery. I have decided to drop back to the 12-12-30 charger. That’s only 9 hours give or take for a completely discharged battery and I believe I’ll be doing enough running around, boat ramps, visiting relatives up at the farm, and seeing friends that I’ll probably always be adding something back.

I am attaching a picture of my battery posts and a drawing….. though I may have messed it up — but I think having a working schematic to follow is the way to go as you suggested. So hopefully all of you can see the detail well enough.

The pos. in from the starter battery goes directly to the charger (in) fused at both ends.

The charger (out) to the house battery and the pos. to the blue seas fuse panel is spliced. Since the pos. to the shunt for control power is a small load I brought it off the fuse panel.

Again, thanks to all for the help. Glenn


IMG_1032.jpeg



IMG_1029.jpeg
 
Glenn said:
..,
After rereading Jon R’s post, doing the simple math of battery AH divided by charged Amps, I have decided the 50A dc to dc charger is overkill for my limited power consumption on the 280 AH battery. I have decided to drop back to the 12-12-30 charger. That’s only 9 hours give or take for a completely discharged battery and I believe I’ll be doing enough running around, boat ramps, visiting relatives up at the farm, and seeing friends that I’ll probably always be adding something back.

…
Click to expand...
I wasn’t going to recommend either way because I respect the desire for margin, but a 30 amp charger would be my choice given those loads, your large battery, and the driving expectations you mentioned, especially if you just have a single alternator with 110 amps output.
 
Thanks for the schematic.

I use a 20 amp DC-DC with my 230AH battery and it's been adequate, I bet the 30 will work well for you.

What size wire from the engine battery to the 12v-12v? Do at least 6 awg. I did 4 awg.

You don't show an enable wire for the 12v-12v charger.

You don't really need a fuse at the input to the 12v-12v charger. It would be better to put a circuit breaker on the output o fthe 12v-12v.

You may need a circuit breaker on the output of the LiFePO battery. Or does the battery have one built in? Does the battery have a built-in BMS? Can you access it via bluetooth? If your battery has that built-in, you don't need the victron battery monitor. These batteries can dump a tremendous amount of energy very quickly. You need some sort of fault protection on that battery's output.

You don't really need the wire between the ground block and frame. It's OK, but not necessary unless it's there for some other purpose.
 
Dadocut said:
.

What size wire from the engine battery to the 12v-12v? Do at least 6 awg. I did 4 awg.
Click to expand...
#4 . I see on the ammeter wire chart that it is rated at 60A for a 20’ run, and same amperage as fuse size reccomenddd by Victron.

Dadocut said:
You don't really need a fuse at the input to the 12v-12v charger. It would be better to put a circuit breaker on the output o fthe 12v-12v.
Click to expand...
Yes, I was planning on a circuit breaker👍





Dadocut said:
You may need a circuit breaker on the output of the LiFePO battery. Or does the battery have one built in? Does the battery have a built-in BMS? Can you access it via bluetooth? If your battery has that built-in, you don't need the victron battery monitor. These batteries can dump a tremendous amount of energy very quickly. You need some sort of fault protection on that battery's output.
Click to expand...
Yes, it has BMS. Protection from charging when too cold and overcharge protection. Don’t know about Bluetooth, I still have to read manual.
 
And, left out the inverter for now to simplify the drawing. Still trying to decide. 🤷‍♂️

Also, I’ve done other Mods using Seal Tite Conduit. I plan to do the same from under the cab into the back of truck bed and some sort of Anderson or similar style plug.
 
Last edited:
Nothing wrong with using 4awg wire, but the terminals on a Victron Orion Smart TR 12/12-30 accept maximum 6 awg. If you use 4awg, at some point you will need to reduce to 6awg for the connection.

Also, I know from my own installation on my 2021 GMC crew cab long bed with a smart alternator, with the FWC Grandby front dinette battery compartment and the Orion located at the rear drivers side corner of the camper, that Ancor marine type 3 6 awg wire is sufficient to prevent excessive voltage drop that would interfere with the Orion’s engine running detection logic. Mine does not need to cycle to check if the engine is still running. My wire run is about 30 feet one way. 6 awg is easier to work with than 4awg and is less expensive.
 
Thanks, I was more worried about adequate protection for the wire as Victron chooses to recommend a 60A fuse. Makes no sense to me to not protect the wire from getting hot and not having the fuse blow first🤷‍♂️

Here’s my resource for the 4 gage wire (Amps and voltage drop) in the graph:

Part 1: Choosing the Correct Wire Size for a DC Circuit - Blue Sea Systems

Engineering high quality marine electrical components for safety, reliability and performance
www.bluesea.com www.bluesea.com

I’ll check for an online site for the wire you referenced. Thanks!
 
I guess it depends which graph selection…. I was going off the “critical 3% resistance drop max)” but if looking at the “non critical - up to 10% resistance drop” then the #6 falls into that category? Any thoughts on the critical vs. non critical?

I found this online:

 
One of the main benefits of the dc to dc charger is it will step up the voltage coming from the truck to the voltage needed to charge your battery per your set parameters. Because of that, you don’t need to be so concerned about voltage drop along the wires from the truck. (You do want the Orion within a few feet of the camper battery to minimize voltage loss on that side of the charger.). You just want to reduce the voltage drop enough that the engine running detection logic can function without cycling the charger on and off. 6 awg accomplishes that. 8 or even 10 awg wire would be acceptable from a wire heating standpoint, but the voltage drop would be enough that, without a third wire telling the Orion the engine is running, the Orion would stop charging every two minutes for a few seconds to verify the voltage rises back to the engine running range.

You can read about the engine running detection logic in the manual.

The truck source side of the Orion is going to draw a maximum of about 35 amps when the camper side is charging at 30 amps. A 40 amp fuse would be marginal for avoiding nuisance trips. A 50 amp fuse or cb would be adequate to protect 6 awg wire and avoid nuisance trips. A 60 amp fuse would be fine, too.
 
Last edited:
OK, thank you Jon R

I’ll plan on using the Anchor 6-2 then with the tinned copper strand. And I like the idea of the 50A fuse.

I double checked by voltage on my truck. During glow plug activation it’s in the low to mid 11’s. Within seconds of the GPR turning off the juice jumps up to 14.2 volts and steady.

With this summer heat I’ll double check again with the loads turned on….headlights, AC on Max Air High, etc.

Thanks!!
 
don't use any chassis parts for wiring. I do run a ground wire from my negative buss/fuse panel to the camper frame, but that's just insurance (the factory does use the framing/sheet metal for grounds) in case one of factory grounds goes bad.

With 4g already run, you do not need to ground the camper separately.
 
Ancor 6-2 will work, but I did individual wires and covered them with split loom along the whole run. I bought a 50 foot roll each of red and black. That left plenty for making cables to use within the camper.
 
craig333 said:
50 foot roll? That stuff isn't cheap!
Click to expand...
Between the truck charger run and the various cables within the battery compartment, I needed about 36 feet of each color. It was about the same price to buy a 50 foot roll of Ancor 6 awg as it would have been to buy 36 feet by the foot, plus that way I knew I’d have enough. I think it was just under $50 for each roll in 2021. Now it’s at $62.
 
You must log in or register to reply here.

Similar threads

O
MPPT controller at 13.64v - Blue Sea meter at 12.35v - Batteries not charging
Jon R
J
R
Victron Controller Unusual Trend
Vic Harder
Vic Harder
R
LifePo Shorepower Charger
Vic Harder
Vic Harder
B
FWC running lights issue
Vic Harder
Vic Harder
R
cold weather lithium charging...
RHarries
R

Latest posts

Back
Top Bottom