We were requested by the customer to upgrade his power management system as he planned to live and work from his motorhome.
The first stage of the upgrade was to remove the out dated and unreliable Sargent power system installed by the manufacturer. The next stage was to modify the wiring loom and internal systems to allow the same functionality as the original system, this was achieved using 5 relays, it does make you wonder why they make these systems unnecessarily complicated.
We installed a Victron Multiplus 2Kva. Victron equipment is a must if you require reliable uninterrupted power. The Victron Multi has an 80amp charger and a 2Kva inverter, it has a mains priority switch built in so if you were unexpectedly to lose shore power it will switch to inverted power so quickly even a computer would not notice.
We installed a Victron colour control to control the system. This has many functions, I have listed the most useful below
- Grid Assist. This is by far the most useful function included in this upgrade. If you own a modern motorhome you probably have lots of 240v appliances you would like to run, possibly at the same time, if you are on a camp site with a 16 amp trip you can draw 3.5 Kw so you will never have an issue, however, if you are in Italy and you are on a camp site with a 5 amp trip you can only draw 1.1 kw. If you have your original battery charger and your fridge running on mains you have almost used the available 5 amps. This will leave no power to run your Tv or microwave and I would be very surprised if your motorhome air conditioning system worked. When you have Grid Assist installed you can use the colour control screen to inform the Victron Multi that it is only allowed to draw 5 amps from the shore power, if you require additional power it will automatically invert any requirements above 5 amps. This means even with a 5 amp supply you can still draw about 3 kw with no issues.
- PV generation. The amount of power being generated by your solar array will be displayed on the screen.
- DC power usage. The amount of power being consumed by your DC appliances will be displayed on the screen
- AC power usage. The amount of power being consumed by your AC appliances will be displayed on the screen.
- Battery condition. I true state of charge will be displayed on the screen.
- Water and waste tanks. Using a CanBus system we can make the tank levels show on the display
- If a generator is installed, you can also use the colour control to start and stop the generator. This can be programmed so the generator only comes on at certain times allowing quite hours at night when the generator will not fire, it can be programmed to turn on when the battery is at a certain level of discharge
To provide reliable power we installed two 100ah Transporter Energy Lithium Ion batteries. These batteries have a very sophisticated BMS which means you can use many different charge currents without damaging the batteries.
The Victron 2KVA Multiplus has a Lithium charge setting so we programmed it to charge the 200ah of lithium batteries. The batteries will allow a C1 charge, this means that each battery can accept a 100amp charge, they can also be discharged a C1 so if necessary, you can continually draw 200amps for 1 hour. Transporter Energy batteries also have a 10-year warranty making them an easy choice for the customer.
We installed 500 watts of solar on the roof using 5 x 100w Victron solar panels. Ideally, we would have liked to have fitted more but these panels filled all the available space. This was controlled using a Victron 150/60 MPPT charge controller. This Victron MPPT controller could accept 150 volts DC and supply a charge current of 60 amps. It is also fitted with a Lithium setting to ensure the battery BMS does not have to work too hard.
This motorhome was fitted with a 150-amp alternator, the engine does not require all the power all the time, so we installed a Victon Cyrix split charge system so any excess charge current produced by the alternator can be used to charge the habitation batteries. This system also allowed the motorhome air conditioning system to be used while the vehicle was in motion.