The camper trailers upgraded power system

After a couple of months on the road we have had few queries and a fair bit of interest in the 12v power system that the camper runs, so we though it would be a good idea to give an overview of what we have installed and our impression so far. So Mat is back on the keyboard today. 

When we purchased the trailer the 12v system was pretty much non existent, there was an old 100a/h deep cycle battery and 2 Merritt plugs on the side of the camper, there was no way to get charge into the battery except by using a stand alone charger and crocodile clamps. 

Knowing that we prefer to camp away from caravan parks as often as we can and that we would be running 2 Engel Fridges; one of which would be a dedicated freezer, we decided that the system would need a major upgrade and some thinking on how to make it work best for us. 

The first thing we did was work out our worst case total power draw (using the maximum a/h draw figures for all of the electrical stuff we have (the two fridges, some LED lights, and all of the gadgets and gizmos we have that need charging) and then worked backwards from there. However the more we looked into it, it became obvious that we were going to need someone with more 12v knowledge than we had, to design a system that would both meet our needs and be robust enough to handle life in the bush.

When looking for someone to help us design the system we got in contact with Jamie and Shane from JTS on the Sunshine Coast, these guys have been building 12v systems for years and specialise in the type of fit out that we wanted to do.  

Many phone calls and emails later (Sorry Shane!!) we landed on a system that we felt would cover all of our bases.

The system. It is located in the box on the drawbar at the front of the trailer. 

 The back bone of the system is 2x 120a/h AGM batteries from FullRiver these came very well recommended as reliable durable power storage options that would stand up to life as a full time power supply, they cost a little more than some other brands but, so far they have proved to be worth every cent. These were installed in Parallel configuration, basically meaning they operate as one big 240a/h storage.

Next we installed a Radarc BCDC 1225 battery manager, this system is capable of managing charge from both the vehicle (from the alternator) and from solar panels (more on this shortly). Having had Redarc products in our last two utes, and a Redarc dual battery isolator in Ruby currently we were happy to use this Australian made product.  Having taken care of 12v charging, we also wanted to add a 240v charging alternative to the system for times when we were in town.  

The Redarc is the black box beside the battery. 

Shane and Jamie recommended a ProCharge Ultra Charger, this is a 30A charger that can be used for bulk charging as well as maintenance charging of batteries in storage.  This system has proven to be perfect for topping up the batteries in town when we have been at a Caravan Park for a few days. 

240v power charger. 

Having taken care of charging we installed a BM1 compact battery monitor to keep an eye on both battery voltages and charge/discharge rates, this has proven to be the most handy piece of the entire set up, allowing us to get a firm understanding of both our power usage, but also to better understand how the charging a system works in various scenarios so we can adjust our use accordingly. 

Battery monitor & inverter

With a number of gadgets and gizmos to charge we knew we needed an inverter, in the end we settled for a Cotek 300w inverter, this is a pure sine wave inverter allowing us to safely charge delicate equipment such as tablet computers and mobile phones, the 300w inverter isn't big enough to run appliances such as kettles and toasters, but so far this isn't proving to be much of a problem for us. 

As the camper was a few years old the plugs and sockets used throughout the trailer were also in need of replacing. We chose to replace all of the existing Merritt Sockets with standard 12v cigar sockets, and also added an additional outlet inside the camper body for use inside the tent.  All of the charging and external connector plugs were changed over to Anderson Plugs, and the cabling    used was upgraded to accommodate for the size of the current to and from each plug. 

Lastly we needed a power source for the batteries when the car wasn't hooked up and we were away from mains power for more than a couple of days. We considered and quickly discarded the idea of using a generator, as that would mean carrying unleaded fuel.  Also we camp in National Parks a lot and some of these have strict rules about generator use. As a result we started looking at Solar panels.  The efficiently and affordability of portable solar panels has improved dramatically over the last few years, with a lot of cheap panels now available on the market.  Talking to the team from JTS it was clear that up to a point with solar you get what you pay for, with the budget end of the market often coming with inflated power figures and poor quality fittings.  However the same was clear from the top end of the market, with the most expensive panels, while they might be more efficient and durable over an extended (years and decades) period, that they didn't seem to offer value for money for us. 

In the end we ended up with  2x 120w panels from the Chinese manufacturer Blue Sun.  These were a mid range panel, to improve the durability of these panels the team from JTS has upgraded all of the clips, plugs and cabling on them to meet our needs, this included bypassing the solar regulators that came with the panels (our Redarc does this job in our system) and replacing the crocodile clamps with Anderson Plugs to match the permanently fitted inlet sockets on the trailer.  

Anderson plugs on the trailer that connect to the car. 

Anderson plugs that the solar panels connect directly to. This then charges the batteries. 

After several trial runs on shorter trips and after 6 weeks on the road it is fair to say that we are more than happy with how the system has worked.  On a sunny day our solar system makes around 15 amps of charge, meaning our system is usually fully charged by lunchtime.  On an overcast day the system is still making enough charge to keep up with our fridge draw (4-5 amps) meaning that even under poor conditions we can last several days without needing to look for an alternative power source. 

The longest period we have been away from mains power continuously now is 16 days, and the system was fully charged the evening before we packed up when we put the solar panels away. This self sufficiency is allowing us to plan longer periods away from mains power, and is also saving us money as we can bush camp more and don't need to pay for powered sites if we choose not to when we do have to use a caravan park. 

The long term durability of  the Anderson Plugs used in most of the systems connection will be interesting, so far they are going ok, but the most used of them are occasionally stiff and hard to use. We have plenty of spares in the event of one failing.

We can't thank the team at JTS enough for their help in designing and building the system, these guys were a pleasure to deal with and their workmanship was first class. See link to their website https://www.jtsonline.com.au.

The long term durability of the system will be interesting, but given the quality of the workmanship and components used, were confident that we will be fine.