Michael Janke

Last modified: November 23, 2023

This document is an up-to-date description of the campervan electrical system. A companion document describes the electronics and monitoring technology.

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 overnight. If we do not receive any sunlight during the day, we consume roughly 100Ah per day.

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 IP-22 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 305 amp-hour SFK (SunFunKits) LiFePo4 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 Orion DC-DC charger that charges the lithium battery from the alternator.
• 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.
• A Thornwave battery monitor/shunt installed between the chassis batteries and the B2B chargers.
• A Victron SmartShunt battery monitor/shunt installed in line with the lithium battery.

Details (12 volt)

Components

Generator	Cummings 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 Switch	WFCO	WF-T30 Generator priority 120V transfer switch. Transfers 120V loads to generator whenever generator is running
Charger/Converter	Victron	IP-22 30 amp DC charger/converter
12V 120V Load Center	WFCO	8930/50 120V breakers, 12V fuses
Solar Panels	GoPower	100W FLEX-110 100W x 2
	Sunpower	110W Sunpower E-FLEX 110 x 2
Solar Controllers	Victron	MPPT 100/20 20 amp MPPT
	Victron	MPPT 75/15 15 amp MPPT
Batteries	Duracell	AGM Group 31 105AH x 2
	SFK	(Sunfunkits) LiFePo4 305AH LiFePo4
Low Voltage Disconnect	Victron	Smart Battery Protect low voltage disconnect. Prevents houes loads from discharging batteries below programmable threshold by disconnecting loads. Permits manual disconnection.
DC-DC Chargers	Redarc	BCDC1240D Battery-to-Battery charger. Charges Lithium battery bank using 12v DC from other 12v sources. Lithium-specific charge profile, 40A current limit.
	Victron	Orion TR-18 DC-DC charger. Charges Lithium battery via alternator
	Amp-L-Start	Amp-L-Start battery maintainer. Uses lithium battery to maintain charge of either AGM or chassis batteries, manually selectable.
On/Off Switch	Blue Sea 6006	On/Off battery switch. Disconnects Lithium battery from all loads and charge sources.
Battery Monitor (Qty. 2)	Thornwave	One Powermon Model BT-DCPM shunt-based battery monitor. Monitors voltage and current.
	Victron	Victron SmartShunt battery monitor. Monitors voltage and current, calculates state-of-charge and remaining capacity.
Solid-State Relay	Thornwave	TL-SSR solid state relay. Allows Thornwave battery monitor to programmatically disconnect the Redarc charger input from the house 12v system.