In this informal tutorial, Kathryn Bird (Speaker A) and her helper Mac replace a failed 300 W inverter in a motorhome with a new 2 kW unit. The video walks through safety precautions (disconnecting the negative terminal first, preventing metal contact between terminals), assessing and upgrading cable size for the higher‑power inverter, physically removing the old inverter and mounting the new one, and routing the thicker cables to the leisure battery. They explain why the original inverter blew—its 300 W rating was insufficient for charging an EcoFlow power station, which draws around 650 W. After installation, they test the inverter using its remote control, monitor battery voltage and load, and successfully charge the EcoFlow. The hosts also discuss choosing the inverter based on reviews, remote‑control capability, and cost. The video ends with a light‑hearted moral about rewarding helpers with a bacon sandwich and a call for viewer questions and subscriptions.
Chapters
So I'm doing electrics. Um, I am fitting a new inverter in the van all by myself with no help whatsoever. Mr. WB is definitely not here helping me out and definitely not telling me what to do so I don't electrocute myself. The dog, the dog is just staring at him. Hi, Daddy. Um, yeah. The inverter in my van broke on my Scotland trip, so I am getting a new one, and I've said I want to fit it by myself because I know lots of people are confused about how to fit an inverter. So I'm gonna fit it with supervision, and hopefully it will help you learn how to fit yours as well, if we don't die. Ah, get off, dog! Get off, dog! Don't ever work with children or puppies. Right, that's my inverter that broke.
Yep.
Look at the dust in it.
What you're fitting is a big inverter.
So an inverter is not like a diesel engine that you want to run hard?
No.
You want inverting to not be maxed out?
Plenty of leeway.
Okay, good to know. So let's unstrap it first of all. Oh, it is just strapped in. Okay, am I literally just pulling the things out the bottom?
No, no, no, because if you pull things out the bottom, they will touch.
Okay, so what middle?
At the bottom, there is, if you can see, The first thing we're going to do is take off the black wire and not let it touch anything else. Get lots of grief from people. You should have done it. I think you're doing the red.
I thought— no, that's the red. I'm doing the black. Not as easy. The dog— can you just pull back to see the dog? What are you doing, Mommy? What are you doing?
Negative off and out of the way. Okay. Positive.
Hang on, I'm trying to film around the dog.
Out of the way.
Okay, so what are these 2 connected to? They're connected to the connections on the battery?
They're got— they're directly to the leisure battery.
Little scratch on the back of that. That's you, that is. That's you. You checking cable. So you're literally just checking the size of the cables?
Yeah, so when I fitted this one, yeah, um, I fitted it with bigger cables.
Okay, so now how do you know what size cable? I suppose these cables came with the inverter, didn't they?
These are thicker, so we're going to change those cables. They're too thin.
Okay, so we are going to go to the battery. That's good, people will be excited about that.
Okay, cool. So this is our leisure battery.
Yeah.
And in here you see I fitted Yeah, I did. I fitted the wires to it. So what we need to do—
Can you pull up that black one so I can see?
You see the black wire there?
Okay, so it's just attached to the terminal.
So a very important point on this is you never want anything to short these 2 terminals. It will explode.
By shorting them, you mean touching them together?
Nothing metal can touch these 2 together. Okay, or Nothing metal can, uh, the wires touch together. So all we're going to do is take that off and swap it out for the bigger cable, and the same on the negative, and put them back one at a time.
Oh yeah, I know, it's very exciting. So all you've done there is you've pushed the lid down the back, and then— so yeah, you've You've put the connection on the side of the bolt, so you've gone the lead, then the thing. Is there a reason for that, or does it just make it easier for you?
Because it's just— because it's on the left-hand side, it'll then just be a bit shorter.
Oh, okay. Yeah, because we're a bit worried about the length, weren't we, of the lead? Okay, that makes sense.
That's all it is. Making sure that the red cable isn't touching the bodywork or anything like that. Nothing metal at the back. Don't go too tight. You want it tight so that it— so it can't Yeah, so the actual, um, battery terminal can't turn, but at the same time you don't want to thread the bolt. People far too many times tighten things far too tight.
From the guy whose Nespresso cup I can never open.
That's just cuz you're weak.
So that is now on, done, covered. So that's now the live done.
That's the live done.
The same on this side. Yep.
The difference is quite substantial.
So that's 300 watts, and this one is?
It's 2 kilowatts.
2 kilowatts?
Yeah, I got it so that you could run a small hair dryer. So what you get, 2 terminals. Yeah, as per the other. Yeah, we've connected the 2 batteries.
So you've literally just popped them on and then screwed them in?
Okay, we're going to put Push this back, and for now we're just going to keep it there until we're, we're happy with it. On, off, on, off.
Okay, perfect.
Done.
Do we want to test it? Could we test it on my EcoFlow? Because that desperately needs a charge, please.
And then—
Thanks, Mac. Thank you. Away, puppy, away. Right, just give it a sec. It always takes a second.
Um, so what we can do, it comes with a remote control, right?
So this was a cable that came with the set?
Yeah, it's got a remote control with it.
So is that why you picked this inverter, because it had a remote control with it?
No, I picked this inverter because it had the best reviews. It was the best output, uh, the most efficient that I could find for the money without spending thousands.
How much was it?
I don't remember, a few, couple of hundred pounds. Okay, so right, plug the cable. It's just a Cat5 cable. Yeah, so you plug that in the front. Yeah, plug it into the back there. Yeah, and then you get this. Okay, now you leave that switched off, you don't turn that on. Yeah, when you want to turn it on, you do this and it tells you your battery voltage.
Okay, hang on, the screen cover thingy. Okay. Oh, hang on, don't move it, don't move it, don't move it, don't move it. There. Stay there.
It tells you your battery voltage.
Yeah.
It tells you your load, so how many watts you're using. So now we've turned it on, let's plug this in. You should see that load start to kick up.
Give it a second. Yeah, yeah, yeah. So what does that 240 volts, 50 hertz—
Yeah, so that's, that's what the inverter is giving out.
Yeah.
That 13 volts is your battery. Now it's up at 13 volts because—
What, the leisure battery?
Leisure battery, yeah, it's charging. Yeah, you're on mains.
So this is a 2,000-watt inverter.
And we're using approximately to charge the EcoFlow, I reckon that's about a third.
Yeah.
So that's drawing probably about 650 watts, this EcoFlow.
Yeah.
Which is why your other inverter wouldn't do it.
Wouldn't— yeah, I couldn't do it.
Yeah. That's what's blown your inverter. You've drawn too much.
That's fascinating. Hadn't considered that.
Glad I got the, uh, the larger one. Yeah, thank you.
Didn't occur to me. I just thought it would use up to 300 watts and it would just charge slower. It didn't occur to me it would blow it. And then those 2 little things here are for like iPads and phones and stuff if you wanted to use those. Yeah, that's cool. So having done investigations, we've discovered that the EcoFlow takes— was it 500-watt inverter?
500 watts.
So if you want to charge it off an inverter, you need at least a 500-watt inverter.
And this inverter was only 300 watts.
Yes, I didn't realize it would go boom. I just thought it would take longer. Okay, so I fitted it in there and he has run the wire all underneath and then down under the carpet into there, around the back here, and it's now in there. So actually, that wasn't anywhere near as terrifying as I thought it was going to be. I feel I did a very good job.
You did an amazing job.
But I did film it, and I'm now going to make a bacon sandwich as a thank you, which I think is a fair trade. So if you don't know how to fit an inverter, find someone who does and make them a bacon sandwich. It's the moral of the day. Thank you for your help.
You're welcome.
If anybody's got any questions, drop them below and I will get somebody who knows what they're talking about to answer them. Uh, if you found this video helpful, a thumbs up is always very much appreciated. And if you're new to the channel and would like more motorhome tips, then by all means hit subscribe. Thank you for your time. I'll see you on the next one. Bye!
