Solar Repair/Upgrade

[Tergra]

The 950w solar package on my 2023 Isata 30FW has performed poorly from day one. Since I have factory Lithium batteries with two 30A Victron MPPT charge controllers, I decided to convert from the factory parallel panel setup to a series setup with three panels wired to each charge controller. After disconnecting all of the factory wiring, I checked the Voc (open circuit voltage) of each of the factory panels. Three of the five factory panels had a Voc of zero volts. The remaining two factory panels had a Voc of 19 volts. As there is a three year warranty on the panels, GoPower quickly replaced the failed panels. I purchased an additional 190w panel to bring my panel total to 1140w. Before installation I checked the Voc on each of the new panels. They all were at 22 volts. I set up and wired the panels to minimize shading on each three panel string depending on the time of day. So far looking at the charge controller voltage trends, each controllers voltage hovers around 57vdc for most of the day with the battery bank at 100% charge. I've attached pictures of the new arrangement and a photo of how hot one of the failed factory panels got. The other panels showed no heat discoloration.

 

[Aussieguy]

where did they put the charge controllers
in cupboard or close to battery?

near battery is best because the higher voltage will allow more amps to get to the controller
then with a SHORT wire from controller to battery you minimize losses
if the controllers in a cupboard away from battery consider re-wiring them?

 

[Tergra]

Regarding wiring from the panels to the charge controllers, the higher voltage of a series setup allows the use of smaller gauge wire. Unfortunately, my ISATA 5 30FW has the batteries located at the back of the coach and charge controllers located at the front so there is some line loss from charge controllers to the batteries as the voltage peaks at 14.6 Vdc in that rather long line run.

 

[Aussieguy]

if you can measure the voltage at the end of the long run .. and it stays above 14.2
then they probably used the correct wire size

my factor pre-installed was totally too small 10g from controller to battery with about 22 foot run
But I had plenty room to put controller next to battery and use a short run of 4g