Electrical
In large part, I copied faroutride and buildagreenrv. Not to brag, but I definitely brought my own research to the table too. I won’t get into academic explanations of sizing wire and breakers etc (though I will if you ask me to), but rather just present the choices I made and a little bit about why. I recommend the 2 resources above, the Sprinter build guide, and industry rules like RVIA and ABYC for more details.
I will explain in words first and back fill with pictures.
The system has an AC system and a DC system. I chose a 12-volt DC system, but I’d consider higher like 24v or 48v if I did it again.
AC (alternating current) System
My AC system has 3 possible sources: an onboard inverter (battery driven of course), RV or EV. I call the 2 different possible shore power sources RV and EV for brevity. The batteries could have been charged by shore, alternator (diesel), or solar. Shore could be a friend’s solar array or a grid-connected coal plant in West Virginia, so this is a very mixed energy source system… as green or as black as you make it in use.
The RV system allows me to connect to a 30-amp RV pedestal or a 15–20 amp wall outlet connection. I use a shore power cable rated for 30-amps and a stainless steel Smart Plug combo kit. I just use an adapter if connecting to a typical wall outlet. This system is highly preferred by those in the maritime field because these outlets really do wear out and cause dangerous problems as mentioned in Smart Plugs advertising. I used a 2.5" hole saw to do the connection straight through the side of the van. This goes through a 30-amp double-pole breaker upon entering the vehicle.
The EV system allows me to connect to a Level 2 EV charging pedestal. There’s a bit to know about this, but I think https://evwest.com/catalog/ is where I got almost everything for this: the receptacle, the little module for communicating that you are a parked EV to the pedestal, etc. I used 3/4" or 1" conduit and a 4" Cantrex box (available at most common hardware stores) to ensure the receptacle was super weatherproof. I put this unit underneath the driver seat and ran the wires in through the seat. This system goes through a 10-amp double-pole breaker upon entering the vehicle. The higher voltage EV allows for a lower current for a given power, given P = V * I.
I found an auto-ranging charger because of the dual shore power voltages. This unit will charge at 70 amps x 12 volts on 120v AC “RV” power and at 100 amps x 12 volts at 240v AC “EV” power.
I had to roll my own manual transfer switch in order to accommodate 3 sources of AC power (again inverter, RV, EV). There are 2 different destinations for the AC power: (AC panel, auto-ranging charger). I’m using 2 rotary transfer switches and an AC grounding bus. The inverter can only be sent to the AC panel. The “RV” power can be sent to either the auto-ranging charger or the AC panel. The “EV” power can only be sent to the auto-ranging charger.
DC (direct current) System
The AC and the DC system interface with each other through the inverter and the auto-ranging battery charger. The inverter transforms DC power to AC power and the converter / charger transforms AC power to DC power.
The backbone of the DC system is the 200 amp-hour x 12 volt = 2.4 kW-hr LiFeP04 battery bank. This is pretty modest by modern standards, but we’ve got a propane range and a diesel hydronic heater, so not super reliant on electrical power for cooking or heating. Tyrah really wanted an oven which pretty much rules out induction stoves. Further, regarding heating, most people that have tried to heat with a heat pump have a backup diesel heater, so we just avoid the heat pump all together. We can inject electrical heat into our hydronic system via our water heater, but more on that here. We went with https://www.lifebluebattery.com/home/index.html because of the BlueTooth app and the 10-year warranty.
We connect that battery bank to Blue Sea bus bars. Then there are just multiple ways to put energy in (alternator, shore, solar) and multiple ways to get energy out (DC, AC). Each of those purposes has a dedicated gadget, per:
We have a battery monitor from Xantrex. The DC system is grounded to the chassis. We open and close a Blue Sea solenoid in response to the State-Of-Charge of the batteries to ensure that we do not over-charge the batteries.
This entry needs a lot more pictures and explanations, but… thought I’d at least get something going.
