Van Power Without Leisure Batteries: How I Accidentally Built a Better System for Less

The Part Where I Spend Money Twice on the Same Problem

There is a very particular kind of stupid that involves buying something, deciding it is not good enough, buying something better, and then tearing out the something better in favour of a completely different approach that you had not considered until approximately ten minutes before you started pulling cables.

That is, more or less, the story of how I ended up running van power without leisure batteries. Twice.

A couple of years back, we had a single starter battery doing the job of a leisure battery. I know. The van came like that. We did not question it for longer than we probably should have. Eventually, the penny dropped, and I went out and bought two Yuasa L36-AGM Active Leisure Batteries at £242 a pop. Nearly five hundred quid. Lovely. Sorted.

Except it was not sorted. Because I also bought a battery monitor off AliExpress for a few quid, installed it, and spent every single morning staring at it thinking the batteries were on the verge of death. Every morning. SHIT. They are nearly dead. Start the engine. Top them up. Repeat indefinitely.

Here is the thing. When I actually ran the voltage calculations, those batteries were sitting at around 50% charge. Two AGMs in parallel, and I had only run the lighting and heating overnight. They were fine. The monitor was not fine. The monitor was the problem. But I did not know that then, so instead I just had low-level anxiety about my electrics for several months.

The Bit Where I Bought a 6000W Inverter and Almost Set the Van on Fire

Not long after, we had also upgraded from our original Jackery 1000 (version one, by now, four years old, Kathy’s laptop had been quietly draining it for most of that time, bless her) to a DJI Power 2000. We had bought the DJI as a portable power bank for work. Plug in the laptops. Do the day job. Sorted.

But then the slightly unhinged side of my brain started thinking. We had been running off a single starter battery, which, again, should never have been used as a leisure battery and yet somehow had been for longer than I care to admit. If I was already upgrading things, why not properly upgrade things? Kitchen sink and all that.

So I bought a 6000W inverter. A cheap one, as it happens, from AliExpress. I had been selling a few of the 3000W versions through my TikTok shop, so I figured: I know what these are, I trust them enough, let us go big. I wired it up. It worked fine. For a while.

Then I noticed the positive lead getting warm. Not warm in a ‘this is just electronics doing their thing’ way. Warm in a ‘this is concerning and I should probably address it’ way. So I fitted a thicker cable. Still warm. Fitted an even thicker cable. Still warm. I was at the point of buying the thickest cable I could find, needing about ten centimetres of it, having to buy a full metre because that is the smallest quantity available online, when it occurred to me that perhaps the direction of travel here was wrong.

The inverter had to go. The leisure batteries had to go. The AliExpress monitor had to go. All of it, out.

The Bit Where the ADHD Kicks In and Saves Me Some Money

This is where van power without leisure batteries started to make actual sense, as opposed to just being a chaotic sequence of events.

The DJI Power 2000 has a built-in 3000W inverter. It runs on LiFePO4 chemistry, which is the safer, more stable lithium option. It has an app. It has a car charger input. It has solar input. It has full monitoring on my phone that does not give me nonsense readings at 6am.

What if I just used this as the main power source for the van? Rip out the leisure batteries. Rip out the dodgy inverter. Sell the lot. Use the money to cover the cost of a couple of additional bits of kit. Make the DJI Power 2000 pay for itself.

Reader, I did that.

What You Actually Need

If you want to run van power without leisure batteries using the DJI Power 2000 as your main source, here is the kit list:

• DJI Power 2000 (online around £800-900 at the time of writing)
• DJI 1kW Fast Charger (around £230) – this is wired from your starter battery and is the main charge source when driving
• MPPT Controller (around £45) – handles your solar input, takes up to 400W of solar via XT60 connectors, smart enough to manage everything automatically
• A bit of patience and a willingness to pull cables until things work

That is genuinely it. No massive lithium install. No smart alternator requirement. No eye-watering battery management system. Total spend on just the DJI kit and supporting hardware: around £1,100. Offset the inverter sale (£75 off Facebook Marketplace) and the two leisure batteries that are still sitting here waiting for a buyer, and the real-world cost is lower again.

For context: a proper lithium leisure battery setup with an MPPT, BMS, and all the trimmings would run you considerably more than that. And you would still not get the wireless monitoring, the built-in inverter, or the ability to expand the system later with a plug-in expansion pack.

How the System Actually Works

The DJI 1kW Fast Charger connects directly to the starter battery. When we are driving, it draws from the alternator, ramps up to just over 1kW, and charges the Power 2000. When we are parked, it reverses the logic: it monitors the starter battery and pushes power back to it if the voltage drops below 12.7V. That is the threshold I have set. Below that and I cannot start the van, so the system just will not let it happen.

My van’s existing control unit needs 12V to run the lights, water pump, fridge elements, and heating. It no longer has a dedicated leisure battery doing that job. What it has instead is the starter battery, which is kept permanently topped up by the Fast Charger via the Power 2000. Through a process of trial and error involving some creative cable removal from the bus bars, the starter battery now handles the 12V side of things, and everything works.

Do not ask me to explain it in more detail than that. I got there through elimination. It works. I am not about to dismantle it to find out exactly why.

The MPPT controller handles the solar. I went from 100W on the roof to 400W after adding three more 100W panels last October (I wrote a whole blog on that here). In Northern Ireland in early May, I am seeing around 200-250W on a decent day. I have yet to crack 300W. We will see what summer brings. The MPPT can theoretically handle up to 400W input, so there is headroom there if the sun ever decides to commit.

The Power 2000 has its AC output, which I can switch on via the app wirelessly. This powers the sockets in the van. When it is on, it also charges our Jackery 1000 (yes, we brought it back into service) which we use as the primary laptop supply. There is also a manual switching box to make sure we are not accidentally running dual power from the AC and an external hook-up simultaneously. Basic fire safety. It matters.

Three Months In

We have been running this setup for nearly three months now. We got through the back end of winter on it, which I will be honest, was slightly character-building. We managed. We would manage more comfortably with an additional 2000W expansion pack, which retails at around £799 and is on the list for later this year. One expansion unit would take the total capacity to 4000Wh. That will do for winter peace of mind.

The thing I keep coming back to is the monitoring. The DJI app tells me exactly what the charge state is, exactly how many hours of power I have left, what the solar is pulling, what the car charger is doing. It is accurate. It does not give me daily heart attacks. The ANCEL BM3000 PRO Bluetooth battery monitor I had on the leisure batteries is in the bin. Literally. I would not sell it to a stranger.

The starter battery is looked after. The 12V system runs. The sockets work. We can make coffee. The fridge runs on gas but the 12V element behaves. The heating works. Kathy’s laptop is no longer a silent assassin of battery reserves.

It is, as I said on the video, just sweet.

The Bottom Line on Van Power Without Leisure Batteries

If you are running a motorhome or campervan and wondering whether you can run van power without leisure batteries, the answer is yes, and the DJI Power 2000 is a credible way to do it. You are not going to need a smart alternator. You are not going to need an electrician. You are going to need about £1,100, an MPPT controller, the DJI Fast Charger, and a willingness to pull a few cables until things make sense.

It is not the most conventional approach. Then again, nothing about this van life setup was ever going to be conventional.

Links to the key bits of kit are in the video description. If you have questions, drop them in the comments below. I will answer them as accurately as I can, which is to say I will tell you what worked for me and gently remind you that I arrived here via a combination of lateral thinking and a mild obsession with not wanting to buy another metre of cable.