Motorhome Solar & Electrical

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Winter here we are! One of the bigger jobs this week was for Mike, who sold the farm last year and has been travelling f...
31/05/2026

Winter here we are!

One of the bigger jobs this week was for Mike, who sold the farm last year and has been travelling full-time ever since. We added a 445W panel to work alongside his existing solar array, installed a Victron 2000W inverter, fitted a SmartShunt for proper monitoring, and upgraded the battery cabling throughout.

The cable upgrade was an important part of the job, but what stood out was just how well everything came together once it was finished. Mike now has a much stronger electrical system to support the way he actually uses the vehicle.

We also finally got an answer for Raewyn and Neil after spending a fair bit of time testing their solar setup. Their existing 720W array simply wasn't performing due to lost efficiency over the years. Combined with the reduced solar conditions we see through winter, available charging power had dropped away significantly. What started as a simple 'solar isn't keeping up' issue ended up having us comparing panel test results against seasonal irradiance data and expected output figures.

The solution was a full replacement with four new 250W panels feeding Victron solar controllers. The numbers are already looking a lot better!

The rest of the week was filled with our bread-and-butter installs, upgrades, fault-finding, and testing work. Every customer comes through the door with a different story and a different challenge affecting how they use their vehicle. Some jobs are simple, some require a bit more digging, but helping people get the most out of their setup is definitely what makes this job so enjoyable.

This wiring arrangement (pic below) was another interesting find from the week. It highlights exactly why we're such big fans of running circuits back to a central distribution point wherever practical. The more joins and additions a circuit accumulates over the years, the more opportunities there are for faults, overloads, and headaches down the track.

Hope everyone is having a great weekend, and safe travels to those out on the road!

Found this little guy during the week.At first glance it just looks like a blown blade fuse, but the melted housing tell...
28/05/2026

Found this little guy during the week.

At first glance it just looks like a blown blade fuse, but the melted housing tells a different story. In this case, the fuse itself was actually sitting loose in the holder, creating resistance and heat buildup over time.

It is a good reminder that electrical faults are not always caused by “too much load”. Sometimes a poor connection is all it takes.

Definitely worth occasionally giving the fuses in your vehicle or caravan a quick visual inspection. If you ever spot discolouration, melting, or signs of heat around a fuse or holder, it is something worth investigating sooner rather than later.

Another solid week in the workshop with a really good mix of upgrade work, fault-finding, and system design challenges.O...
24/05/2026

Another solid week in the workshop with a really good mix of upgrade work, fault-finding, and system design challenges.

One of the bigger jobs this week was a lithium upgrade for Merv, built around a full Victron setup to cover all charging sources. What made this one particularly satisfying was that the plan evolved once we opened the vehicle up. We originally had another mounting location in mind for the Victron 1200W inverter charger, but after taking a closer look we realised we could mount it neatly under the driver’s seat instead.

That ended up being a much cleaner solution overall. Keeping the inverter charger close to the batteries helped minimise cable lengths, reduce voltage drop, and make far better use of otherwise wasted space. Combined with an additional 400W of solar on the roof alongside the existing array, the system now has some very solid off-grid capability heading into winter.

We also spent a good part of the week working on a beautiful Hino bus for a couple deep into a major reno. The goal there was to completely overhaul the electrical side of the vehicle and give them a safe, reliable foundation to continue building from. We reworked the 230V side to bring everything up to a much better standard, while installing a complete Victron-based system to handle the DC side of the build as well.

Towards the end of the week, things shifted into a mix of smaller jobs. Battery replacements, satellite fault diagnosis, and plenty of testing work filled the days up.

One job in particular has had us deep into the numbers. We have been investigating a set of four solar panels that appear to be underperforming, but the answer is not quite as straightforward as it first looked. Between panel testing, system measurements, and cross-checking available irradiance and seasonal solar data, we have been trying to answer a surprisingly difficult question: are the panels actually failing, or are they simply performing as expected for this time of year? We'll update as we find out more!

That side of the job is something we genuinely enjoy. There is a lot more science and analysis behind solar performance than most people realise!

Safe travels for those out on the road this week!

303V AC at the inverter output. 😳 This is one of those faults that really reinforces why we test every system properly b...
19/05/2026

303V AC at the inverter output. 😳

This is one of those faults that really reinforces why we test every system properly before touching anything else.

Interestingly, most failed inverters we come across tend to go the opposite direction — low voltage output, unstable operation, shutdowns under load, things like that. Seeing one overshoot this dramatically is much less common.

In this case, the inverter was a particularly cheap unit, and while it still appeared to be “working”, the output voltage told a very different story.

For those interested, this type of fault is usually caused by a failure in the inverter’s regulation or voltage feedback circuitry. Essentially, the inverter loses its ability to correctly control the AC output voltage, and instead of maintaining ~230V, the output can climb well beyond safe operating range.

The scary part is that a lot of appliances will still appear to function… briefly.

Battery chargers, TVs, coffee machines, microwaves, laptop chargers, induction cookers - they all rely on stable AC power. Feed them 300V+ and components inside can overheat and fail quickly.

This is also where cheap inverter design really shows itself. Better-quality units generally have multiple layers of protection and will shut themselves down long before things get this ugly.

Needless to say, this inverter has officially been retired...

Another busy week wrapped up!One of the more memorable finds this week was definitely that earth connection we posted ea...
17/05/2026

Another busy week wrapped up!

One of the more memorable finds this week was definitely that earth connection we posted earlier. Safe to say it was not memorable for the right reasons. It sparked some good discussion online, but it also highlighted just how important proper workmanship and attention to detail really are in these systems. The small things matter, especially when safety is involved.

On a much more positive note, we completed a very tidy 1600W inverter replacement for Mike in his beautiful Frankia motorhome. The original unit had done well with around 7 years of service before finally calling it quits, so we swapped it out for a Victron Smart inverter and got things back up and running again.

We also had AJ back through with her awesome full-time van setup. She has put a huge amount of thought and learning into the project over time, and this week we added the final piece to her charging system with a Victron Smart mains charger. She is now set up for campsite top-ups as she continues travelling around the South Island through the colder months.

Aside from that, there were battery upgrades, inverter installs, fault-finding jobs, and a surprising amount of solar panel testing coming through the doors this week as well.

I finished the week by heading along to the local rally at the Classic Car Museum. It was great catching up with a few past customers and having some good conversations with people questioning their electrical setups. Most looked to be in pretty good shape already, but we will definitely be seeing a couple of them in the workshop next week.

Weeks like this are always a good reminder of how varied this industry really is. No two systems, customers, or jobs ever seem to be quite the same.

A car worthy of its own post!Last week we mentioned the owner Johnny’s Honda Civic VI-RS… and a few people wanted to see...
15/05/2026

A car worthy of its own post!

Last week we mentioned the owner Johnny’s Honda Civic VI-RS… and a few people wanted to see more 👀

This car is a pretty good reflection of how we approach everything here at Motorhome Solar & Electrical. Every detail has been thought through carefully, nothing rushed, nothing “good enough”.

From the wiring and fabrication, right through to the tiny finishing touches most people would never even notice, Johnny has put an insane amount of time and care into this build.

That same attention to detail carries straight through into the workshop and every install we do. Clean, tidy, reliable work that’s built properly the first time 🔧

This is one of those small details that can create a very big headache later on. Safe to say that a few particular words...
14/05/2026

This is one of those small details that can create a very big headache later on. Safe to say that a few particular words were said when we saw this...

The panel on the right needed to come up for unrelated work, but because the panels were mounted this close together, the fixing hardware became completely inaccessible. What should have been a straightforward removal turned into a much bigger job.

It is a good example of why system design is not just about making everything fit. It is about thinking ahead to servicing, fault-finding, upgrades, and future access.

There is a huge difference between something that technically works, and something that has been properly planned!

Sometimes giving yourself an extra 10mm of clearance can save hours of labour down the track.

This one gave us a bit of a shock this week.What you are looking at here is supposed to be an earth connection. A small ...
14/05/2026

This one gave us a bit of a shock this week.

What you are looking at here is supposed to be an earth connection. A small piece of wire twisted around a bolt and trapped under a washer. No lug, no proper termination, no mechanical security, and no confidence that it will still provide a reliable connection once corrosion and vibration set in.

To our standard, this is about as poor as an earth connection gets.

Earthing is one of the most important parts of any electrical system in a motorhome or caravan, but it is also one of the most overlooked. Most people focus on batteries, solar, and inverter size, while the grounding side of the system gets ignored.

The problem is that earth connections are there for fault conditions. They are there to provide a reliable, low-resistance path when something goes wrong.

On the DC side, poor grounding can create all sorts of strange behaviour. Voltage drop, charging inconsistencies, unstable electronics, communication faults, heat buildup, and unreliable system performance can often be traced back to poor earth paths or inadequate return conductors.

On the AC side, the stakes get much higher. Once you are dealing with 230V, proper earthing becomes a critical safety system. RCBOs and other protection devices rely on fault current having a proper return path in order to operate correctly.

This is especially important in inverter-based systems, because the inverter is an isolated source. Without proper neutral-earth bonding and compliant earthing arrangements, safety devices may not trip as intended during a fault condition.

The frustrating part is that proper earthing is not complicated. It just requires care, correct materials, proper terminations, and attention to detail.

Good electrical work is often invisible when it is finished. Unfortunately, so is bad electrical work until something stops working, or somebody gets hurt.

It’s been a solid week in the workshop with a good mix of major upgrades and general maintenance. Here’s a quick look at...
10/05/2026

It’s been a solid week in the workshop with a good mix of major upgrades and general maintenance. Here’s a quick look at what’s been keeping us busy.

We mentioned Brent’s battery relocation earlier in the week. We pulled his two external batteries and moved them inside alongside his third battery for a much cleaner, more efficient setup. While we were in there, we replaced the factory Projecta monitoring system and fitted a Victron SmartShunt so he actually has in-depth, accurate data on his power usage. We also caught an inaccurate mains charger and swapped it out for a Victron 12/30 Smart Charger to ensure his newly relocated bank gets charged properly.

Next up was Geoff’s Jayco Conquest. He is making the move away from relying on LPG, so we swapped out his old setup for a new Dometic RUC8508X compressor fridge. It's a great addition to the system and a smart move for long-term reliability.

We also knocked out a few odd jobs between the bigger solar and electrical installs, including a thermostat replacement and fixing up some stop and brake lights for Cath and Mike.

On a personal note, our owner Johnny and a few mates spent the weekend showing off their polished Honda Civic VI-RS builds at REVCON. We only mention it because the absolute fussiness and perfectionism those guys put into their cars is exactly the standard Johnny sets for this workshop. It’s all about the details. That exact same mindset is what goes into our electrical installs: we don't settle for 'near enough is good enough', we just focus on doing the job right down to the last cable tie.

Hope everyone had a great weekend! We've got a few hours left until next week is full, so get in touch if you're wanting your system looked at!

Another interesting find in the workshop this week.This inverter is advertised as a “3000W” unit, but there are a few pr...
08/05/2026

Another interesting find in the workshop this week.

This inverter is advertised as a “3000W” unit, but there are a few pretty major clues that tell a very different story.

To produce 3000W from a 12V battery system, an inverter needs to pull around 250A continuously. That is a huge amount of current. At those levels, cable sizing becomes absolutely critical.

The small cables supplied with this inverter simply are not capable of safely carrying that sort of load continuously. In fact, the warning label on the inverter itself more or less admits it: stating the cables may burn if the inverter is heavily loaded. That should immediately raise alarm bells.

Then there’s the physical size of the unit itself.

A genuine 3000W continuous inverter requires substantial internal components and serious cooling capacity to handle the heat generated under load. Large transformers, heavy copper, sizeable heatsinks and proper airflow all matter here. Physics always wins.

When an inverter is this physically small and lightweight, it becomes pretty difficult to believe the claimed continuous rating.

This one is also a modified sine wave inverter, rather than pure sine wave. That means instead of producing clean, smooth AC power like you get from the grid at home, it produces a much rougher waveform. While some appliances will tolerate this, many modern devices really do not like it.

We regularly see modified sine wave inverters causing:

- noisy appliance operation
- excess heat in motors and compressors
- unreliable charging behaviour
- issues with sensitive electronics

For motorhomes and caravans, we strongly recommend sticking with properly rated pure sine wave equipment from reputable brands.

Electrical systems are not an area where unrealistic marketing claims are worth the risk.

Address

22D Kaimiro Street
Hamilton
3200

Opening Hours

Monday 8am - 5pm
Tuesday 8am - 5pm
Wednesday 8am - 5pm
Thursday 8am - 5pm
Friday 8am - 5pm

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