Lithuium battery and solar panel install

[johnno]

Nearly finished installing the lithium 50ah (tiny) battery and two solar 50W flexible solar panels for my Eclipse, so thought it might be useful to document the experience here. The aim is to run a Dometic CXF3 25L cooler, chartplotter, radio, phones/tablets and the standard lights for day and multiday trips.  The outboard has a charging function but I use it so little it would be useless for keeping the battery charged. I'm also not sure if I could even use it with my lithium battery.

After a bit of to-ing and fro-ing this is the system I've come up with. It's been quite a learning experience for me, to do with wiring and electrics on the one hand, and solar and battery systems on the other.  I should add that I also have a shore power lithium battery charger that I can use to top up the batteries before a trip if I need to, and that also we plan when possible to chill the fridge right down using shore power for 30 minutes or so before we leave on longer trips, and we should be able to achieve that while we pack the boat.  The boat is in a wet berth by the way.

I decided on the bimini for the pv panel location as it was the least unsightly and most out of the way.  We started with one solar panel and one mppt controller, but moved up to two flexible pv panels and two controllers when we decided to add the fridge.

With the boom splitting the panels on the bimini, and some shading almost always present, we found the two controllers and independent panels more productive of power than linking the panels in either series or parallel with one controller.

The we also added a shunt so that we could see the state of charge in percentage and charge remaining (in hours), rather than just seeing the present voltage.

The controllers and shunt both work through the iphone (read-outs, plus updating and changing settings) so there was no need for any extra instruments.

The two controllers, two buses, and the shunt all fit along the upper wall of port side berth out of the way but close to switch panel, battery, and pv panels.

So far it seems to work really well, but we have yet to do an overnighter.  We did spend a day on the boat though with fridge, chartplotter and vhf runnning and the solar panels kept the battery fully charged with plenty to spare.  The fridge I should say is really efficient.

Photos show the physical install of the controllers etc and also some screen shots of the Victron apps working with the two controllers for each panel and also the smart shunt.

[crazycarl]

What size wiring did you use from the panels to the controllers?  My 50 watt panel came with and reccomends 10 gauge, but the 10g. wires barely fit into the controller and if bumped, will pull out. 

You're installation looks nice and clean.

[5monkeys]

This looks fantastic, I got a 50 Watt panel for our 19.. hoping to install it on the sliding hatch cover..

[Jim in TC]

Great looking system...I must say, the tech (controllers, monitoring, refrigeration specifically) since we left our off-the-grid farm 12 years ago has taken some leaps. Of course, some of our equipment dated back to the late 80's when we built, and that stuff is *really* out of date!

[Fastdoc98]

I'd love to see pictures of the mounted panels!

[johnno]

What size wiring did you use from the panels to the controllers? 

Hi Carl, I used 25amp tinned marine wire which is 2.9mm square so roughly 10 gauge, but it seemed to go in okay. I'm actually thinking of putting ferrules on the ends but that means buying yet another crimping tool probably.

[johnno]

I'd love to see pictures of the mounted panels!

There are some pics in an earlier post of mine.  Link is below if you can't find it. Actually they were taken when I had only put up one panel, but the second is just a mirror. I'll see if I can find another pic and add it just so they're all in one post.  I used the 'stay-put' toggles, but changed the way they're normally used by putting the canvas of the bimini and the solar panel between the two washers of the screw up toggle. It holds well, and the toggle bit is redundant really.

https://cpyoa.com/forum/index.php?topic=12334.0