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2020, 136, HR in Seattle
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Discussion Starter #1 (Edited)
Hi folks, after a lot of researching, reading here, collaborating with friends, and designing, I've arrived at a tentative electrical design. I would appreciate feedback from the knowledgeable folks here; I'm set on most main components, but welcome any feedback, specifically on design, wiring, fusing, and wire gauge calculations.

From a high level, I have three possible charge sources, though solar and B2B are likely the main use cases. These sources charge two parallel BattleBorn lithium 100Ah house batteries, giving me 200Ah. I also have a 2000W inverter/charger for AC loads and infrequently topping off the charge via AC input.

More specifically, the system breaks down into:

Main components:
  • BattleBorn Lithium 100Ah (2)
  • Kisae DMT1250 50A MPPT solar controller/B2B charger
  • Kisae 2000W IC122055 inverter/charger
  • Newpowa 150W solar panels (2)

Three charge inputs:
  • 300W solar (handled by Kisae DMT1250)
  • Alternator/B2B charger, up to 50A (handled by Kisae DMT1250)
  • 15A AC input (handled by Kisae IC122055)

Diagnostic:
  • Kisae DMTRM1201 for monitoring incoming solar and B2B charge
  • Victron BMV-172 for monitoring battery levels

DC loads:
  • MaxxAir fan
  • Webasto heater
  • Shurflo water pump
  • LED puck lights (ceiling and kitchen)
  • Dometic fridge
  • LED strip lights (garage)
  • USB plugs (phone/tablet charge)
  • 12V accessory plugs (vacuum, chargers, any misc item)
  • Potential 12V laptop charger

AC loads:
  • Two laptops (~80A each?)
  • Monitor
  • Magic bullet
  • Potential WiFi router, cell signal booster

Layout (136' WB):
  • Permanent elevated full size bed in back
  • Electrical on right (passenger) side by wheel well
  • Water under sink in cabinets on left (driver) side behind seat


Here is my electrical diagram:


69810


Thanks for any input!

(edit: updated diagram's wire length readability)
 

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3/0 awg seems a little big. My battleborns are connected with 2 awg and I haven't had any problems.

Same with the run from the starter battery to the DC-DC charger, according to the BlueSea circuit wizard app 3 awg should be adequate. It's a handy little app, more precise a than a chart, also calculates fuse requirements.

Fuses and breakers should go near the ends of the wires. I would use fuses unless its on a circuit where the switch function of a breaker would be occasionally useful, if you install everything properly you shouldn't be blowing fuses very often if ever.

You should have plenty of power at your disposal based on the loads you listed.
 

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Hi @cocolocomoco21

I’m sure you will get lots of response regarding wire size, fuses, etc.

I noticed you have 2 - 2 position switches. Have you considered 1 - 4 position switch ?

69815

69816
 

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Discussion Starter #4
3/0 awg seems a little big. My battleborns are connected with 2 awg and I haven't had any problems.

Same with the run from the starter battery to the DC-DC charger, according to the BlueSea circuit wizard app 3 awg should be adequate. It's a handy little app, more precise a than a chart, also calculates fuse requirements.

Fuses and breakers should go near the ends of the wires. I would use fuses unless its on a circuit where the switch function of a breaker would be occasionally useful, if you install everything properly you shouldn't be blowing fuses very often if ever.

You should have plenty of power at your disposal based on the loads you listed.
Thanks for the reply. Using that tool, I am also seeing slightly less thick numbers, like AWG 2/0 for the battery terminal. Looks like the tools and charts I used are slightly different, so I'll give this another run through with the BlueSea circuit wizard.

One question is regarding the B2B line. If I'm doing the full positive and negative run, I come out to AWG 1. Do you have any insight there? I've read that it's advised to run the negative back to the DMT1250 (really good write-up here: link), but I'd be curious if you think I can ground off the starter battery's ground or elsewhere.

The diagram doesn't show this well, but my intention is to fuse/breaker near the device. I was designing with breakers just to be able to isolate parts of the system (e.g. shut off all charging, shut of alternator charging while driving on a sunny day, etc.), but I can see if there are places where a fuse might be better as well. Thanks for the feedback.
 

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Discussion Starter #5

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I have not, but that's a really good idea. So that would allow me to have power flowing in and out of 1) the inverter, 2) the battery bank, 3) both, or 4) neither?
Yes - the 4 positions are;
All Off
1 On
2 On
1 & 2 Both On

Caveat; If switching between individual sources position 1 or 2 - you either have to go thru “both” or “off”. This may be important depending upon your system setup (it may not be important). Solar power for example if the solar controller want the panels turned off before disconnecting the battery.


When I was doing my van electrical I went to buy a 2 position switch & the 4 position was right beside it & was $5 more. I bought the 4 position with out knowing how I was going to utilize the function, but I came up with a need/want and was glad I purchased it basically on a gut feeling it would be a simpler cost effective decision - it was.

*note the 350amp continuous rating

I have a lot of ideas, the odd one is even good.
 

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I don't even think you can fit 2/0 into the starter battery compartment. I has trouble fitting my 4awg. I used 4awg because it was the largest size that fit my Sterling charger. From the manual for your unit. Not sure what can fit, but looks like they are assuming around 6 gauge. Edit: looks like it takes ring terminals so maybe you can fit larger wires on this one.

69830
 

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Discussion Starter #8
@ferall and @RV8R, I've updated my wiring diagram to more accurately reflect wire gauge size and including the 4 position switch.

69849


I don't even think you can fit 2/0 into the starter battery compartment. I has trouble fitting my 4awg. I used 4awg because it was the largest size that fit my Sterling charger. From the manual for your unit. Not sure what can fit, but looks like they are assuming around 6 gauge. Edit: looks like it takes ring terminals so maybe you can fit larger wires on this one.

View attachment 69830
@aaronmcd that's a good call regarding the wire size fitting into the unit, thanks for pointing that out. Also, do you think AWG 1 would fit off the battery, underneath the floor, around and through the driver's side step, and back toward and eventually up the B pillar? I've seen your description of this approach, but curious if you think the thicker wire would handle the slots and curves.


(edit: forgot to attach diagram 🙃)
 

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I have a similar system (no solar yet) but it's in front of the driver side wheel well. I mounted the DMT-1250 to the front of the box (where I can see the panel) and tee-spliced a 4 AWG run from the upfitter power connector under the driver side step, before that heads across to the passenger side B-pillar. (I just rely on the stock 70A fuse). I use a single battery switch near the DMT-1250 to disable alternator charging. My BBs are coupled with 2 AWG, as are my + and - bus bars. (I also have another single battery shutoff you can see before the + bar). The silver box you see the side of is a Powermax PM3-45LK AC-DC charger/power supply from my shore power. There's a shallow AC outlet (out of view) the Powermax plugs into, where I also have an AC plug feeding the (blue) DC-AC switching inverter (AIMS Power 1200W).

If you're installing on the passenger side and you have the upfitter power connector, you could just remove the connector itself and tap into the 4 AWG + with a barrel connector, but you may have to build a slightly raised floor to run it across the slider opening. (Shorter run to the DMT-1250 using my approach, but we also want shallowest floor and ceiling because we're 6'4" and 6'2").

Also, in addition to fusing and wire-sizing, you can protect the alternator feed by programming the max current the DMT-1250 will charge the BBs with (default is 30A).
69850

69852

69853
 

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@ferall and @RV8R, I've updated my wiring diagram to more accurately reflect wire gauge size and including the 4 position switch.

View attachment 69849



@aaronmcd that's a good call regarding the wire size fitting into the unit, thanks for pointing that out. Also, do you think AWG 1 would fit off the battery, underneath the floor, around and through the driver's side step, and back toward and eventually up the B pillar? I've seen your description of this approach, but curious if you think the thicker wire would handle the slots and curves.


(edit: forgot to attach diagram 🙃)
I'm not sure about 1 gauge. This was my first electrical work I've done. I only used 4 different sizes:

I chose 2/0 awg for the batteries and to the switch and bus bar. Those were tough to bend and fit - you have to cut pretty exact lengths because excess wire is very hard to deal with. They can be cut with handheld wire cutters if you squeeze between your thighs and regularly work on your squats lol.

The next size down I used was 4awg running from the starter battery to my 60 amp dc charger above the rear driver side wheel well. Probably 12-13 feet each wire (house ground to starter battery, charger ground to starter battery, charger positive). I upsized this just because I was concerned about accurate voltage measurements for the lithium charge profile and because the charger uses starter battery voltage to know when to charge and when to turn off. It's working fine so far, but I've only taken the van out for one trip yet. 4awg was not bad to work with but still needed the hammer crimper and stripping with utility knife.

I also used 4awg to run to my DC fuse block. I chose 8awg for my next size down for the longer solar runs. I bought wires premade with solar connectors and cut the end that goes to my charge controller.

I'm using 12awg for all my DC loads. It's small enough to be easy to work with and easy to buy connectors for, and large enough to handle any loads I may have - fridge, propane heater, pump, lights, gas alarm, roof fan, etc.

Oh also my inverter came with double 4awg wires so I didn't size these myself. So far they work fine but only used them for boiling water for coffee and charging phones/lamps.
 

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Oh some minor deets; here's the extension cord I used for AC input. Your graphics show USB chargers on the AC which you may want to forego as there are ample 12VDC options available, and these days you'll probably want Quick Charge 3.0 (QC3), especially if you're charging tablets. (This one I just got to replace the stock one up front; will test if the annoying light stays on before buying another for the back).

For the battery monitor do some searching. Some on here swear by the Bluetooth Victron, but if you're not going to use that then my understanding is the BMV-712 is rebranded and you can find the exact model much cheaper with some sleuthing. I don't have one yet, and based on a recent thread here I'd even consider battery choice to the LifeBlue which has Bluetooth SOC built in - compelling because the manufacturer (theoretically) can best determine the charging and decaying profiles of their own batteries.

Lastly - memory just jogged by Aaron's pics - consider whether you want to pay more for tinned copper vs copper lugs/wires, especially if you plan on long ownership and/or around salt water.
 

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The cable that aaron used looks like it isn't very flexible at all, which might be part of the difficulty he experienced.

Welding cable is very flexible, I don't think you need to worry about tinned cable, it adds quite a bit of cost and heavy guage cable is already pretty spendy.
 

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The cable that aaron used looks like it isn't very flexible at all, which might be part of the difficulty he experienced.

Welding cable is very flexible, I don't think you need to worry about tinned cable, it adds quite a bit of cost and heavy guage cable is already pretty spendy.
Yeah I got that wire at Lowe's and it was quite stiff. I ended up picking up more at NAPA and the insulation was much more flexible.
 

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Discussion Starter #15
I have a similar system (no solar yet) but it's in front of the driver side wheel well. I mounted the DMT-1250 to the front of the box (where I can see the panel) and tee-spliced a 4 AWG run from the upfitter power connector under the driver side step, before that heads across to the passenger side B-pillar. (I just rely on the stock 70A fuse). I use a single battery switch near the DMT-1250 to disable alternator charging. My BBs are coupled with 2 AWG, as are my + and - bus bars. (I also have another single battery shutoff you can see before the + bar). The silver box you see the side of is a Powermax PM3-45LK AC-DC charger/power supply from my shore power. There's a shallow AC outlet (out of view) the Powermax plugs into, where I also have an AC plug feeding the (blue) DC-AC switching inverter (AIMS Power 1200W).

If you're installing on the passenger side and you have the upfitter power connector, you could just remove the connector itself and tap into the 4 AWG + with a barrel connector, but you may have to build a slightly raised floor to run it across the slider opening. (Shorter run to the DMT-1250 using my approach, but we also want shallowest floor and ceiling because we're 6'4" and 6'2").

Also, in addition to fusing and wire-sizing, you can protect the alternator feed by programming the max current the DMT-1250 will charge the BBs with (default is 30A).
View attachment 69850
View attachment 69852
View attachment 69853
Thanks for the info. How do I know for certain if I have the upfitter connector? I have three 70a fuses on the starter battery, and I thought having the available spot means I don't have the upfitter, but after looking at some other posts (e.g. this one), I'm seeing that possibly the third fuse (circled green in that link, which I do have) is for the upfitter? I can always check the passenger B pillar, but I've already installed and silicone-ed my floor around the plastic guard, so I'd like to avoid needlessly moving that if possible.


Oh some minor deets; here's the extension cord I used for AC input. Your graphics show USB chargers on the AC which you may want to forego as there are ample 12VDC options available, and these days you'll probably want Quick Charge 3.0 (QC3), especially if you're charging tablets. (This one I just got to replace the stock one up front; will test if the annoying light stays on before buying another for the back).

For the battery monitor do some searching. Some on here swear by the Bluetooth Victron, but if you're not going to use that then my understanding is the BMV-712 is rebranded and you can find the exact model much cheaper with some sleuthing. I don't have one yet, and based on a recent thread here I'd even consider battery choice to the LifeBlue which has Bluetooth SOC built in - compelling because the manufacturer (theoretically) can best determine the charging and decaying profiles of their own batteries.

Lastly - memory just jogged by Aaron's pics - consider whether you want to pay more for tinned copper vs copper lugs/wires, especially if you plan on long ownership and/or around salt water.
I was actually planning on taping over those USB connectors on the AC plugs in favor of dedicated, more efficient DC USB charging in the walls :). I'll give QC3 chargers a look, thanks for the link. And good call on the battery monitor - I used the Victron as a placefiller, since it's so widely used and recommended, but definitely wanted to do more research there before pulling the trigger.
 

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Discussion Starter #16
The cable that aaron used looks like it isn't very flexible at all, which might be part of the difficulty he experienced.

Welding cable is very flexible, I don't think you need to worry about tinned cable, it adds quite a bit of cost and heavy guage cable is already pretty spendy.
Yeah I got that wire at Lowe's and it was quite stiff. I ended up picking up more at NAPA and the insulation was much more flexible.
Thanks for the info with wires. It sounds like welding cable is the way to go? Flexible and less expensive? I'd use the van in moist environments (PNW climate + ski seasons), but definitely want to keep cost and usability in mind.
 

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Thanks for the info. How do I know for certain if I have the upfitter connector? I have three 70a fuses on the starter battery, and I thought having the available spot means I don't have the upfitter, but after looking at some other posts (e.g. this one), I'm seeing that possibly the third fuse (circled green in that link, which I do have) is for the upfitter? I can always check the passenger B pillar, but I've already installed and silicone-ed my floor around the plastic guard, so I'd like to avoid needlessly moving that if possible.
Regarding the 70Amp Upfitter Fuse;

The example you gave is my photo. The 3rd fuse circled in green was my upfitter fuse. I disconnected the upfitter wire at the fuse & removed it from the battery box & tucked it behind the drivers stepup plastic cover. That wire goes to the upfitter connections behind the passenger seat @ the “B” Pillar.

I then attached my charging wire to that 70amp fuse & ran it to the back under the bed to my house battery bank. Details are on my build thread.

My PM van is a 2018. I’m assuming Ram did not change this for your year.
 

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Thanks for the info with wires. It sounds like welding cable is the way to go? Flexible and less expensive? I'd use the van in moist environments (PNW climate + ski seasons), but definitely want to keep cost and usability in mind.
I haven't seen any corrosion in a couple years in the PNW, it's not that damp here compared to a boat on the ocean where electrical failure could have catastrophic results.
 

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I haven't seen any corrosion in a couple years in the PNW, it's not that damp here compared to a boat on the ocean where electrical failure could have catastrophic results.
I live near the PNW also.

I agree the corrosion issue in this area “depends” on proximity to the ocean.

We love camping near the ocean shore. Corrosion is a major cause of electrical failure on saltwater used boats. We purchased “marine” grade wire for our van. Might be overkill for some campers as it depends on their intended use. It was not a massive costin comparison to the rest of our build.

Here is a warranty exclusion that is typical for the sheet metal industry (red circled);

69874
 
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