- Polaris Overland.
Trailer Solar Power Upgrade
Lots of new bits and pieces had been arriving for the Land Rover and the Trailer whilst they were away getting resprayed. As we mentioned in the previous blog Dave was struggling without the two of them to work on resulting in us both spending more time on the route planning and the dreaded packing.
When we initially moved out to Cyprus, and as we had two furnished houses back home in the UK, we said we would not buy too much whilst here. So roll on 8 years and we have everything and then some more! So now we are sorting, selling and packing. Sorting what we want to keep. Selling what we do not want to keep. Packing everything we do want to keep and to be shipped home to the UK.
So Dave in particular was very happy to get the Land Rover and Trailer back so he could escape the sorting or packing and get on with the many jobs that need to be completed.
The trailer needed the new reflectors installed and the new solar system installed. All bolts on the trailer lid needed to be removed and rubber sealing washers added as rain had a habit of getting in at the bolts.
So its been a busy few days, the bolts are done, the reflectors fitted and the solar system installed. The previous Solar System we used was a makeshift affair bought off the local classified ads page that was cobbled together as a trial run but which worked surprisingly well to the point we used it for 2 years.
However a solar system in sunny Cyprus would have to be really poor to not work and as our travels would take us to countries with less sunshine the decision was made to upgrade. Additionally the original solar panel was a solid framed house panel which was both heavy and bulky. Both of which we wanted to get away from.
We contacted a number of Overlanding Groups for guidance and advice and the solution that seemed our best option was to install 2 x 60W Flexible Solar Panels with an MPPT Charger. Dave being from a marine background liked the Victron Charge Controllers and Display as his experience of their marine equipment was good, being reliable and well built. More details can be found here :- www.victronenergy.com/solar-charge-controllers/mppt7510
The MPPT Charge Controller was chosen as the only viable solution as it works well with multiple panels and with voltages significantly higher than the batteries which compensates and adjusts to satisfy the requirements of the batteries. Additionally by good positioning of the panels even when one is in direct sunlight and the second in partial shade the system again compensates to meet the requirements of the battery. All of this results in a more efficient charge. If you need a more technical description there are various threads on google such as this :- comparing-pwm-and-mppt-charge-controllers/
In practical terms the flexible panels are lightweight, easy to move and position whether the Roof Top Tent is packed away or set up. The flexible panels are designed with marine use in mind so should stand up to the weather and the vibration
The first job was to remove the old PWM Controller which meant disconnecting a lot of the Electrical Box.
This was not so easy due to the restricted space however new MPPT Charge Controller was installed.
The Display Unit was mounted in the electrical box door and the communication cable run internally. The display unit allows us to monitor the parameters and if needed change settings for the charge algorithms.
Next issue was how to run the solar panel cables to the top of the trailer. We were loathe to drill more holes in the trailer so the cables were run internally in the rack tubing and into the electrical locker then electrical box.
The cables have the waterproof MC4 Connectors for the external connections to the solar panels. As there are two panels a Y Adapter was needed to allow both panels to be connected to the single +ve and -ve cables to the Charge Controller.
With the panels temporarily mounted on top of the packed Roof Top Tent the system was tested.
In relative shade we were running approx 20W giving a charge of around 1.5 Amps.
Bearing in mind it was early evening I was surprised to get any charge and the picture below shows the sunlight at that time.
The system has been left running now for two days and once the batteries were charge the system has been running in float mode to maintain the batteries at optimum charge by maintaining a the charge and discharge current at a similar rate.
I have additionally added a connection from the charge controller to run the fridge in the Land Rover in the event the Aux Battery in the Land Rover fails or to extend our off grids time.
Hopefully we will now be able to spend longer off grid without a need to charge up the system,