Electrical Diagram Review & Questions

[jakehow]

Been reading the forum for a while now and finally getting my build going, I picked up a bunch of parts on Black Friday this year and trying to arrange them in a way that works now which is probably not the best way to approach, but hey...

This design borrows liberally from some of the active members here but has a few unique aspects. I have a 2017 144 Crew 4x4 with Aux Battery. We are using this as a weekend camper for a family of 4 and is my daily driver as well.

The diagram is still under construction a bit but thought I would try and get some feedback before finalizing (some missing runs, terminals, wire gauges, etc). Trying to figure out how to make it not look like a mess in omnigraffle still . The PDF is easier to read the small text in.

The plan is for equipment under the passenger seat to be wired to the Aux battery and everything else to be wired to the house batteries. They will be connected through the Magnum MS2012 via a Blue Sea Rotary Switch for charging while driving.

Aux Battery (Stock):

• Espar D2 under passenger
• Rockford Fosgate PBR300X4 driving front and rear Hertz speakers, connected to stock head unit for now
• Samlex PST-600-12 Inverter

House Battery ( 2x 170AH Renogy Lithium):

Solar Charging:

• 3x 100W Renogy Eclipse Panels on Roof in Parallel
• Renogy Rover 40A MPPT Charger

Inverter/Charger:

• Magnum MS2012
• Can be connected to shore power or vehicle inverter via BlueSea Rotary Switch

AC Loads:

• True Induction TI-1B Stove w/ dedicated outlet
• 4x Outlets:
  • Laptops
  • Electric Kettle
  • Maybe Microwave or Instant Pot

DC Loads:

• MaxxAir 7500 Fan
• Lighting:
  • 2 Pairs of LED Floods on Roof (Left and Right)
  • 1 Pair of LED Floods on A Pillars
  • Backup Light mounted in Camera Housing
  • 8 3w LED pucks in headliner
  • 6 3w LED pucks under cabinets
  • LED strips in Galleys
  • LED Work Lights on Rear Doors
• TruckFridge TF49DR-SS
• 4x 12 Volt Outlet Panels
• VIAIR 20001 Air Compressor Kit
• Shuffle 3 GPM 55 PSI Water Pump
• Whale Pumps 3gallon 12v Water Heater

The 12V heater and the Air Compressor will be on separate circuits b/c the Paneltronics panels don’t have 35A breaker option and the rocker switches in the panel are only rated to 20A.

After putting this together I have a few questions I was hoping the forum members could help me with:

1. Theres a jump from 250A bus bars from Blue Sea all the way to 600A, I am assuming because of the 300A spec’d fuse for the inverter I need to go with the 600A bus bars?
2. Is it ok to have 2 terminals on one post of the main bus bars or should I get the 8 post versions?
3. Are the 300A shutoffs that I am using for the battery and the inverter sufficient or should I swap them for 350A variation to ensure the fuse fails first?
4. Do I need to protect the Blue Sea A/C Switch that I am using to switch between the vehicle inverter, shore power and off? Are 30A breakers ok here if so, or should the be 25A?
5. The Renogy batteries have overcurrent protection which can be reset only using their controllers (which I am), do I need additional protection with some sort of low voltage cutoff? Opinions on if the built in overcurrent protection is sufficient?
6. How should I size the breaker going to DC distribution panels? Max possible usage vs most likely max scenarios?
7. Is connecting the Renogy Battery Monitor to the same shunt that came with the Magnum BMK kit the optimal thing to do?
8. Is there a simple way to add monitoring for the aux/starter battery while in camp mode?

Anything else I should be concerned about or need to adjust? Thanks!

 

[autostaretx]

I assume those 1.5 amp loads on your roof are lights?
12 gauge wire up there seems needlessly excessive ... 14 gauge (or even 16) would suffice.
(added: and then i found that the long run feeding them is 14 gauge)

--dick

 

[jakehow]

I assume those 1.5 amp loads on your roof are lights?
12 gauge wire up there seems needlessly excessive ... 14 gauge (or even 16) would suffice.
(added: and then i found that the long run feeding them is 14 gauge)

--dick

Agreed, but I had some leftover laying around at the time and went with it. Is my assumption right that with correct breaker sizing this is no issue?

 

[OrioN]

Move the Espar D2 from the Aux/Stock battery to the house/LI's. (Or, add a power source selector switch).

The Aux./Stock battery can only supply a maximum of 50% of it's ~100aH for ~50aH.

The D2 on high will use ~4A, so you will only get a max of 12 hrs run time between charges.

 

[autostaretx]

Agreed, but I had some leftover laying around at the time and went with it. Is my assumption right that with correct breaker sizing this is no issue?

Correct.

--dick

 

[jakehow]

4. Do I need to protect the Blue Sea A/C Switch that I am using to switch between the vehicle inverter, shore power and off? Are 30A breakers ok here if so, or should the be 25A?

I found (most of) the answer to this one by actually reading the manual(http://assets.bluesea.com/files/resources/instructions/6635.pdf), go figure.

It does not specify maximum breaker sizes but given that the actual rating of the switch is 32A, assuming I can put 30A breakers on both inputs and the output.

 

[AndyMAC]

I have the Espar D2 installed with a selector switch. Before adding our 2 Battle Born's we used the factory aux to power everything (lights, 2 Maxx air fans, charging phones and Espar) and worked just fine over night. We could stay stationary for two nights but the second night was a little stressful watching the voltage. Now I would use the Factory Aux for the first night, and then switch over the the Li Pack for any additional nights.

Also, it looks like (and I am no expert) that your Shunt is coming off the same battery as your load. I always thought that if you have the load coming off battery 1 you want the shunt off battery 2 (or the last battery in the bank)

 

[jakehow]

I have the Espar D2 installed with a selector switch. Before adding our 2 Battle Born's we used the factory aux to power everything (lights, 2 Maxx air fans, charging phones and Espar) and worked just fine over night. We could stay stationary for two nights but the second night was a little stressful watching the voltage. Now I would use the Factory Aux for the first night, and then switch over the the Li Pack for any additional nights.

Also, it looks like (and I am no expert) that your Shunt is coming off the same battery as your load. I always thought that if you have the load coming off battery 1 you want the shunt off battery 2 (or the last battery in the bank)

Thanks. Did you mount the selector switch in the seat pedestal? How are you monitoring battery condition on the Aux battery?

 

[OrioN]

Thanks. Did you mount the selector switch in the seat pedestal? How are you monitoring battery condition on the Aux battery?

There are remote battery monitors that allow for multiple banks, which naturally require a shunt per bank.

 

[AndyMAC]

Thanks. Did you mount the selector switch in the seat pedestal? How are you monitoring battery condition on the Aux battery?

My switch is under the seat pedestal. I usually just keep it on the factory aux position so the controller doesn't have to restart every time I turn the lithium batteries on. I have a voltage meter display in an upper cabinet so I can check on things. My system is so that I can actually switch and use the factory aux battery for the driver side of my van (1 maxx air fan, water pump and some lights) just in case my Li Pack gets low (only using solar and shore power charging for now).

 

[autostaretx]

Yes, the shunt is drawn confusingly ... hopefully you ONLY have the wire to the battery bank on the "left" end, and all of the other negative connections (including the one to the power bar) on the "right" end.

That way, all current to/from the Lithiums passes through the shunt, and the "right" end is at "system negative".

--dick

 

[jakehow]

Ok, planning on adding a battery selector switch (Blue Sea 6008200) and I found a Victron BMV-702 cheap on Amazon Warehouse to monitor Aux and the Starter voltage.

I had planned to copy the design I have seen on the forums, where all negative leads back to the negative post on the house battery for the house system and the equipment in the passenger seat pedestal uses the factory ground under the drivers seat. Now that the components in the front can be powered by the house battery does this present an issue when the switch is in that position?


Also, I understand how to hook up the shunt, just need to draw it more clearly

 

[autostaretx]

... I understand how to hook up the shunt, just need to draw it more clearly

I'm being picky about it for two reasons:
(a) up 'til now, we couldn't tell if you understood shunts
(b) to help the NEXT guy who copies YOUR drawings...

Ok, planning on adding a battery selector switch (Blue Sea 6008200) and I found a Victron BMV-702 cheap on Amazon Warehouse to monitor Aux and the Starter voltage.

I had planned to copy the design I have seen on the forums, where all negative leads back to the negative post on the house battery for the house system and the equipment in the passenger seat pedestal uses the factory ground under the drivers seat. Now that the components in the front can be powered by the house battery does this present an issue when the switch is in that position?

This is where your choice of drawing style gets in the way of answering that.
i.e. all the same-color lines spanning the drawing to reach the "physical" locations,
instead of using a "schematic" style so that current flows (and what segments move when a switch is thrown) are more clearly followed.

Which switch? On a quick pan-and-scan of your drawing, the only "switch" i notice is the "AC Charging Shore/Inverter Switch (Blue Sea 8367)" in the control panel box?
(plus the two cut-offs just above the Magnum MS2012, but they don't "transfer" anything).
added after first posting: ahh... your proposed Blue Sea 6008200 ... since we don't know where/how you're inserting it, answering is impossible. I think.

By "house battery" do you mean your Lithiums? (in which case the "negative post" is the right end of the shunt, not the left). Or do you mean the Aux Batt?
If the "system ground" (right end of shunt) is common with the Sprinter's "ground" (frame), everything should work properly. (or may not care ... how your system and the Sprinter starter battery (which is what i assume is at the other end of the arrow rising from the radio's Head Unit?) are cross-connected isn't too at all clear.)

--dick

 

[jakehow]

I'm being picky about it for two reasons:
(a) up 'til now, we couldn't tell if you understood shunts
(b) to help the NEXT guy who copies YOUR drawings...

I definitely appreciate this, and I appreciate the threads where people came back and updated their wiring diagram until it was sorted out so I will try and keep mine up to date and post the finalized working version here as I adjust it and complete the install.

Added:
* clearer shunt drawing
* ground in the rear of the van for the lithium batteries
* BMV-702
* Selector Switch under seat pedestal to switch off the Aux when low
* added the aux battery to the drawing for clarity and to draw the shunt for BMV-702
* added run from back of van to the 6008200 with AWG 6 cable

Thanks for all the help so far.