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Discussion Starter · #1 ·
Dammit here, just requesting some kind feedback on my wiring diagram set up before I re-re-finalize my decisions :)

Context:
Planning on building a "simple" camper van, not a live-in /full-timer van.
The electrical setup location is behind the Driver's side in the back, over the wheel well.
  • 2021 RAM Promaster 136WB
  • No built in stove, AC, or toilet
  • No large central water tank, just a 6 gallon under the kitchen galley and a separate 2.5 gallon in the rear fo a shower (2 x H2O pumps)
  • mostly using 14-2 and 12-2 awg for my 12v devices
  • wanted to save $ so my wire choices may seem odd but I tried to go larger ie. I just bought 2/0 and 4 awg wires
  • still not sure what solar setup I am getting between 200W-400W of solar
  • already did my pre-wiring for my 12v and 120v wires

Any tips and advice are welcome, first timer who is 3 months into the build...

Thanks,
Dammit, Van

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Discussion Starter · #7 ·
Batteries: With 1x 170AH Renogy your max discharge is 125A. Given your possible load (1000w microwave + others) that is getting rather tight for my taste. I'd either do 2x 175AH or 2x 100AH (max discharge 200A)
I may scale back to a 700w microwave, I wonder if that would help. I wasn't aware of the 125A max output part Thanks! I figured 1000w would meet the inverter threshold 2000w, 4000w peak. 1000w/12v = 83.333Amps. I guess I'd have to know what the peak surge for the microwave usually is, ie. 1500w * 12v = 125Amps!
700w/12v = 58Amps <-- im wondering if this calculation would be safer than 1000w...

Water pumps: Why two? Just extra cost when one will do just fine.
(Edit: I missed the extra water container for the shower. Running PEX is easy and simpler. I'd honestly just combine the tanks and use one water pump. If that is what you want to do though it seems fine)
I'm thinking this is just a space saving issue for me. I'd prefer to have smaller water jugs compared to a bigger 10-12 gallon tank to maintain. If I were a full-timer van lifer, I'd go with the bigger tank. For a weekender/vacationer van, I'm fine with having smaller refillable jugs.

Breakers: Make sure you buy good breakers (MP,NTE, Optifuse. MP specifically has been found to have quality breakers) The cheap amazon knockoffs will give you problems.
I got these Tocas branded breakers off of Amazon, I saw one of the youtubers recommend these breakers

AC: Does your inverter have a built in breaker? I would be nervous about not having any breakers in my AC. Right now your battery will actually shut down before your DC breakers pop if your AC short circuits and that is a lot of wattage to dump somewhere.
I'm planning on not having shore power, hoping that the alternator and solar charging will be enough. I plan on buying this 2000w GoWise inverter Will Prowse recommends. Someone mentioned that it has "internally fused with 4 30a fuses, for 120a". I've see a few videos of people just connecting 12-3awg extension cables into the inverter for AC

Bus bars are 250A rated Blue Sea for both + and -
Going with a simple propane Coleman camp stove setup, I am never 100% level at camp sites I can't see myself liking a stationary stove setup.
Just to clarify the 2 pumps would be for 2 separate water tanks, one in the Galley 6 gallon and one in the rear for a shower/rinser.

Agree with Steve on dropping the 250 amp breaker near the house battery - the battery terminal fuse provides better and more reliable protection.
Hmm this is something I've seen in multiple builds, I pretty much copied that setup. I'm wondering what the logic in those setups were... ie. Seven-O-Savage diagram
 

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Discussion Starter · #11 ·
I'm guessing he copied it from someone else who copied it from someone else and so on.
I think I may have misunderstood his specific setup. So the other setups I copied probably had multiple batteries connected in series, whereas I only have a single 170Ah
 

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Discussion Starter · #19 ·
How far is you B2B and batteries from the starter battery?
It's a 136WB and the battery/electrical is near the driver's side wheel well.


It's what I did and it works, but stick with the manual if you aren't comfortable. Grounding back to the starter battery takes more wire, but it's simple and straight-forward.
I already chipped the paint out for the ground location in the back near the driver's wheel well, no going back now lol. I just wanted to be sure after I re-checked the manual. I've also read that you get better electrical current using 2/0 awg on the chassis rather than 4 awg ~10 feet or so to the starter battery.

Thanks for clarifying, it makes me feel better that you confirmed
 

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Discussion Starter · #21 ·
@van_dammit Would you be willing to post your finalized diagram (or as close to finalized as it can be at this stage)?
Absolutely! I fixed a few things people pointed out, I hope this helps out

  • added some approximate wiring distance to give a better idea of where things are at
  • fixed the Shunt connection in the diagram
  • removed the 250A breaker between the house battery and Blue Sea On/Off switch
  • decided to ground the Negative busbar to the van chassis with 2/0 awg instead of the 4 awg to the starter battery
  • changed my mind about the inverter, going with 2000W Renogy instead of the Gowise, just to stay on the same brand as much as possible. Plus the Renogy was on sale for the holiday.
  • going with a 700W microwave instead of 1000W just to be safe
  • updated the Diesel Heater wire to 12 awg instead of 14 awg
  • 12 awg for my LED Cabinet lights is overkill but I ran out of 14 awg and had just enough 12 awg to run it

Questions:
  • 4awg on going to a 90A breaker to my Blue Sea 100A Fuse block, is this okay to go smaller if I have to? Reason is that the 100A Bussman breaker may not arrive until mid December, I can get the 90A in a few days...
  • should my 80A breaker be closer to the starter battery? if so I might look at putting it by the driver's seat instead of in the back with everything else. I don't really like the idea of electronics near me just in case I spill a drink or something but hey, I guess I have a starter battery underneath my feet driving.
  • where can I find a 250A name brand breaker? Blue Sea and Bussman only go up to 200A. I have two of these now TTocas 250A breakers (return window exprired) Any thoughts here?

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Discussion Starter · #36 ·
Isn’t the 14AWG to the fridge a little thin?
The fridge is on the same side as the electrical box so it is fairly close and not really concerned with the voltage drop. The ICECO is fairly low power draw

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Discussion Starter · #37 · (Edited)
Your battery rated at 125A isn't up to the task of a 2000W inverter. Look at eBay I found Renogy 100Ah Lithium for $375/ea (asking$400) get two, then use a battery selector switch (not an off/on switch) to parallel them, will be ok for 200Amps. Take the DCC-50 to the starting battery ground. The van has poor grounding thru the body, most of the panels aren't welded, but joined with a goop.. It's very important to have 0 ohm reading and zero voltage drop. I know you have a fuse block, but I really prefer a DC Distribution Panel to easily secure power to devices. Your heater will be on all the time, lit up wasting power. With the DC panel, you can delete the pump switches. 14 AWG is an overkill for LED lights, one light you have 12AWG. Connection 22AWG to 12AWG is a pain. 14AWG, is fine for cig outlets. Motors and compressor are the devices that voltage drops hurt. but with a lithium battery you are running at a higher voltage than LFA batteries. So voltage drops aren't a problem. Most wiring problems, it's never the wiring size, it's always the connection points. Unless someone made a gross error.
Now I have heard both sides to the Grounding debate. I got some advice to not ground to the starter battery due to the wire length of the 4awg cable. I've carved out a chassis grounding spot near the negative busbar and planning to use 2/0awg cable to connect it to the van, that sounded like it made more sense. But I do see all that "goop" between metal panels on the 2021.

I'm leaning to having the shorter cable setup even though the Renogy manual says to ground to the starter battery. I suppose I can change it up later if I start having bad results but others have said they get a better connection through the 2/0awg cable

I dont plan on having anything running in the van that is more than 1500W, i think the most would be a 120v water heating element which is 1300W draw. I've seen someone that has the same setup, 170AH with 2000W inverter. Also Renogy recommends that one 170AH is the minimum battery quantity for a 2000W inverter ::shrug
 

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Discussion Starter · #38 ·
Hi van dammit


Questions:
  • 4awg on going to a 90A breaker to my Blue Sea 100A Fuse block, is this okay to go smaller if I have to? Reason is that the 100A Bussman breaker may not arrive until mid December, I can get the 90A in a few days... I think you will be fine with the 90, but best to size the wire for the 100
I actually found a 100A Blue Sea breaker, so I think I should be all good here

Really appreciate this, thanks. We also have the 136" wb and expect similar loads so this is a great guide. A few differences in our plan:
  • Two 100aH SOK LiFePo batteries (currently out of stock)
  • Holding off on solar for the first year
  • No diesel heater or weBoost to start
  • CPAP is another 120v load
Do you mind if I modify your diagram and post it here for input? Despite hours of research, the electrical remains far beyond my comfort zone!
Sure thing Kathyks, I actually grabbed this diagram from someone else on this board and then Photoshopped my own stuff! I think that visuals, real pictures, help a lot for me
 

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Discussion Starter · #39 ·
Instead of the 80 amp breaker.

Its the 100 amp MEGA fuse in this picture - not the most elegant hookup, but you get the idea...
This is looking down on the van battery.


Gary
Gary, I may return this 80A breaker in lieu of this method. Just one question as to why you chose a 100A fuse on the battery? Isn't the default stock alternator in the PM at 70A? I thought 80A would be enough, no?
 

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Discussion Starter · #40 ·
Quick reminder that given the max discharge of the battery that 250A fuse will never pop. The BMS will shut the battery down first.

250A Breaker - 353250 OptiFuse | Circuit Protection | DigiKey Marketplace
I'm guessing that the other 250A breaker before the 2000W inverter is also probably useless. I didn't realize there was the 125A max output on the batteries, I missed that detail.

I suppose if I ever add another 170AH battery, they would come in play...
 

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Discussion Starter · #43 ·
Part of using the smaller breaker on the house battery side was that if the charging current went substantially over 80 amps it would alert me by blowing
Thanks for the explanation, that clears up my confusion. Im thinking I could do the same here since I do still have my 80A breaker, put it on the battery side as well to trip off any overcharge. Would that work in my scenario? with the 80A fuse + 80A breaker, or would the fuse blow before the breaker?
 

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Discussion Starter · #46 ·
Last revision:

  • replaced the 250A fuses and breakers for a 125A fuse and 120A breaker to the inverter (125A Max output of the 170AH battery)
  • removed the extra water pump, I'll use a portable water pump with the cigarette outlet 12V, gives me an extra wire for lights or CO2 monitor
  • added an 80A fuse on the starter battery to DCDC, kept the 80A breaker to turn off that battery connection if needed
  • downgraded to 320W solar, 2x160W Newpowa (smallest I can find to save room on the roof)
  • 50A breaker from the solar to isolate solar

If i need more power, i would consider buying another 170AH battery and up the fuses/breakers to 250A
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Discussion Starter · #50 ·
I was looking at the specification sheet for the battery you have. BATT-LFP-12-170.pdf (renogy.com) It is impressive. If you believe their life cycle charts the battery can deliver ~8 mwh cycling 30% DOD! (3 mwh @100% DOD) The battery also has an impressive short circuit specification. Looks bullet proof.

I'll point out my pet OCD issue. The wiring diagram has three control elements in the high current inverter loop. A post fuse, a disconnect and the breaker. That is a lot of connections (each one costs power and voltage drop) and all functions can be served by one breaker replacing the disconnect switch.

Other than that, a super clean design.
I see, I could just eliminate that 120A breaker between the Inverter and the Positive Busbar. That 2/0 awg wire would be a short run ~1ft. That would save me some much needed space.

Yes the 125A post fuse wire would be the same size wire, 2/0 awg, so it seems like it would be protected to the Inverter. Last thing I want is a voltage drop to the Inverter, I just wanted to err on the safe side.

Thanks for the pointers on this, I've learned a bunch!

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Discussion Starter · #52 ·
Hello, I see from your diagram that you are using a 125 amp fuse mounted to the terminal of your 170 amp Renogy battery which uses a M12 bolt and requires a 1/2" ring terminal, have you found a fuse that will fit? I have been looking with no luck!
Yes, this is the odd thing about those Renogy 170AH batteries is that the terminals are 1/2 inch. I just bought the Blue Sea terminal fuse and drilled out the hole to 1/2" using a drill press and step bit and now it fits fine.
 
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