FREQUENTLY ASKED QUESTIONS
WHAT SPECIFIC EQUIPMENT DO YOU HAVE?
WHAT DO YOU NEED ALL THAT POWER FOR?
The vast majority of the time, I don’t drain it below 50%, but this does give us a lot of flexibility.
Without air con or solar, we typically use 100Ah per day charging devices, the coffee machine, hairdryer, toaster, routers, TV, etc. This would allow for about 9 days off-grid without moving and no solar. Solar can be very hit or miss in winter - some days we can completely meet our needs with solar, other days we get negligible charge.
Most high power devices (coffee machine, hairdryer, toaster) are only used for a few minutes at a time, and use minimal power overall. Air con is the exception. This typically uses 100A, so after 2 - 3 hours a night, you will be taking a serious hit after only a couple of days. With four of us in the van - and often staying in places with no shade (e.g. Disney) - air con is an absolute must for us in the summer or we will all be very cranky!
HOW MUCH DOES IT WEIGH?
The combined weight of all components in the power system is 180kg, which is mostly the batteries. I allowed for 10kg of cabling and other bits and removed a 24kg Lead Acid battery. I estimated this would add approx 230kg total and I did weigh the vehicle a couple of weeks before and shortly after - this seems to be pretty much the net result. The air conditioning adds an additional ~40kg.
Do not add this kind of setup without understanding your payload and visiting a weighbridge. I knew I would be adding a setup like this and specifically bought a motorhome with a 1,000kg payload (I had to pass an HGV C1 test in the process). Battery positioning is also key to ensure you don’t overload your rear axle.
HOW DOES CHARGING AT CAMPSITES WORK IN PRACTICE?
Each of my 50A mains chargers consume 5A on the AC side, which can be problematic for charging while using the motorhome on hook up. Both of the chargers are powered by a standard kettle lead type connector, wired into the vehicle electrics. They also have switches making it easy to control when they are powered. I also carry additional kettle leads to provide flexibility.
Campsite hook ups seem to vary from 6A to 16A. If I'm using a 3Kw device (e.g. hairdryer) that will take 13A - if the hook up supply can take it, I’ll switch off the chargers and use that direct.
If I’m on a 6A supply, I’ll leave the inverter on and use a converter to turn my hook up lead into a regular 3 pin socket, connect a kettle lead to that and plug into one of the chargers. This will allow a constant charge into the van via one charger and allow me to use 3Kw devices as usual without tripping the power.
This setup gives me the most flexibility. I carry extra leads and connectors which sometimes allows me to use multiple 6A hook ups (e.g. one for the van, one for the chargers, or one for the van and one for the electric hotplate).
HOW DOES CHARGING ON THE MOVE WORK IN PRACTICE?
Each of my B2B chargers output about 60A, given voltage drop and how they are configured. Most of the time I have one connected and it keeps things topped up nicely.
When I first had the setup installed, I had both always on and I rarely needed solar or mains charging as the batteries would just charge so quickly. This felt like a bit of a waste as even when it’s sunny, the solar isn’t going to work if there isn’t anywhere to put the energy. I turned one off to give the alternator a bit of a break and benefit from the solar.
Having the second B2B is critical for our summer trips, where we’re often travelling between off-grid locations and using air con extensively.
WHY VOTRONIC AND NDS BATTERIES?
I’ve used this equipment before in my caravan and it’s absolutely rock solid. There is cheaper gear out there (I see good reports of Victron) but I’ve seen a lot of people buy cheap batteries and end up replacing them.
Aside from the inconvenience and cost, all the freedom and flexibility a system like this provides vanishes if it fails. Without power, we don’t have any of the essentials - a fridge, heating, lighting, hot water, running water or even a flushing loo. Not a fun place to be.
WHY NOT A POWEROAK / JACKERY?
I have a couple of these too. If you have less demanding needs this might meet the requirements, but it doesn't meet the demanding charge / discharge needs we have. I carry a PowerOak as a backup device.