Campervan Electrical

Last modified: July 23, 2022

This document is an up to date description of the campervan electrical system.

Overview

The campervan has one bank of AGM batteries and one bank of a single lithium (LiFePo4) battery. Electricity is supplied by solar panels, an on-board generator, the factory Ford Transit alternator, or 12v volt ‘shore power’ from a household wall outlet and extension cord.

The air conditioner and microwave require 120-volt AC. The lights and water pump required 12-volt DC. The furnace, hot water heater and stovetop are propane fueled, but are controlled by 12-volt electric.

In the current configuration:

  • Charge sources are the campervan alternator, the 200w rooftop solar, 220W portable solar, shore power (plugging the camper into a wall outlet), and a Cummins Onan generator. The alternator and shore power sources charge the lithium bank. Either battery bank can be charged by the solar charge source.
  • The alternator can charge the lithium battery bank at a 60 amp via DC-DC chargers. The chassis starter battery and AGM bank can be charged from the lithium bank.
  • The charger/converter can charge at a 30-amp rate when plugged in to shore power or on generator.
  • The 12-volt lights and appliances can only be run from the lithium battery bank.
  • The 120-volt microwave, air conditioner, and outlets can only be used if the campervan is either plugged in or the generator is running.
  • We use about 40 amp-hours overnight, so either driving or running the generator for an hour recovers most of what we use.

The 120 volt AC electrical consists of:

  • A 2800-watt Onan gasoline generator that draws fuel from the Transit gasoline tank and generates 120-volt AC.
  • A 30 amp ‘shore power’ connection that feeds 120-volt AC from a standard 30A campground outlet and extension cord.
  • A WFCO transfer switch that automatically transfers load to the generator anytime it is running.
  • A 120-volt load center with circuit breakers that feeds 120-volt appliances (microwave, air conditioner) and 120v outlets.
  • A Victron IP-22 charger/converter that supplies 12 volts DC to the 12-volt side of the campervan.

The 12 volt DC electrical consists of:

  • A 30-amp Victron charger/converter that supplies 12 volts DC.
  • A 200-watt GoPower solar array.
  • Two SunPower 110W solar panels, one roof mounted, one portable.
  • One Victron 75/15 solar controller
  • One Victron 100/20 solar controller
  • An OEM Ford heavy duty 250 amp-hour alternator.
  • Two 105 amp-hour Duracell AGM house batteries.
  • One 300 amp-hour SFK LiFePo4 lithium battery.
  • Two OEM 70 amp-hour AGM chassis/starter batteries.
  • A Victron programmable low voltage disconnect that disconnects the house loads from the batteries when the batteries are discharged.
  • A Redarc 40-amp DC-DC charger that charges the lithium battery with a LiFePo4 specific charge profile. Limits current to 40A to prevent overload of other charge sources.
  • A Victron 18-amp DC-DC charger that charges the AGM batteries from either the alternator or the lithium battery bank.
  • An A/B switch that manually transfers the MPPT solar chargers between either the LiFePo4 or AGM batteries.
  • An A/B switch that manually transfers the Amp-L-Start battery maintainer between either the chassis or AGM batteries.
  • A 12-volt load center that distributes and terminates 12-volt circuits throughout the campervan
  • A solid-state relay (SSR) that can programmatically disconnect the Redarc charger input from the house 12v system.
  • Two Thornwave battery monitors/shunts installed in line with each of the AGM and chassis batteries.
  • A Victron battery monitor/shunt installed in line with the lithium battery.

Details (12 volt)

Campervan Electrical – as built, 10/2020

Components

GeneratorCummings Onan 2.8HGJBB 3800 watt, 120V AC. Gasoline fuel sourced from chassis gas tank. Generator is hanging under the campervan behind the rear axle.
Transfer SwitchWFCO WF-T30 Generator priority 120V transfer switch. Transfers 120V loads to generator whenever generator is running
Charger/ConverterVictron IP-22 30 amp DC charger/converter
12V 120V Load CenterWFCO 8930/50
120V breakers, 12V fuses
Solar PanelsGoPower 100W FLEX-110 100W x 2
Sunpower 110W Sunpower E-FLEX 110 x 2
Solar ControllersVictron MPPT 100/20 20 amp MPPT
Victron MPPT 75/15 15 amp MPPT
BatteriesDuracell AGM Group 31 105AH x 2
Battle Born Lithium LiFePo4 100AH LiFePo4
Low Voltage DisconnectVictronSmart Battery Protect low voltage disconnect. Prevents houes loads from discharging batteries below programmable threshold by disconnecting loads. Permits manual disconnection.
DC-DC ChargersRedarc BCDC1240D Battery-to-Battery charger. Charges Lithium battery bank using 12v DC from other 12v sources. Lithium-specific charge profile, 40A current limit.
VictronOrion TR-18 DC-DC charger. Charges Lithium battery via alternator
Amp-L-StartAmp-L-Start battery maintainer. Uses lithium battery to maintain charge of either AGM or chassis batteries, manually selectable.
On/Off SwitchBlue Sea 6006On/Off battery switch. Disconnects Lithium battery from all loads and charge sources.
Battery Monitor (Qty. 3)Thornwave Two Powermon Model BT-DCPM shunt-based battery monitors. Monitors voltage and current.
VictronVictron SmartShunt battery monitor. Monitors voltage and current, calculates state-of-charge and remaining capacity.
Solid-State RelayThornwave TL-SSR solid state relay. Allows Thornwave battery monitor to programmatically disconnect the Redarc charger input from the house 12v system.

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