Choosing solar panels and MPPT

[steve.armitage Find all posts View Profile Close steve.armitage]

I think i want to mount a solar panel to my RR Pioneer platform which will keep the batteries topped up while parked up at home and also while out and about/camping. Ideally the solution will allow me to keep my 60l ARB fridge (~24Ah) running all of the time, at least in the summer anyway, where it's been very useful for picnics, etc., as well as running some lights while camping (~5Ah). I understand that while driving, the alternator will charge the batteries more than the solar will. I don't use the Prado much during the week, so when i forgot to unplug the fridge, the batteries were low (12v & 11.3v) and i've not been on a good drive in the last couple of weeks to top them up.

Solar seems a more flexible option than a mains battery charger.

Which solar panel/capacity
I've been looking at these thin mono panels https://www.vicoffroad.com.au/sport-...ging.html.html
At 2.5mm, i thought these would be a little more aerodynamic than the regular panels which are 30-40mm. With some board/rubber matting over them i'm hoping to still carry things on the roof.
There are also notes on the solar panel pages about not being able to connect these in series or parallel - which sounds like i cannot extend the set up by adding more panels while stationary if required - i.e. if i get a second fridge or run inverter/more appliances/etc. Where originally, i was looking at 100w-120w, i'm now wondering if i should get 150-200w to cope with any future expansion, if i'm unable to run these panels in conjunction with any others.

The 200w version would line up nicely with the outside pioneer rails https://www.vicoffroad.com.au/sport-...-kit-1293.html

I've only seen reports of people mounting the framed pannels on a roof http://www.pradopoint.com.au/showthr...us-solar-panel so unsure if there is an issue if i bolted these to my pioneer platform. I've not seen any examples of mounting these flexible panels to a roof rack.

Which MPPT


Where do i start. I've not been able to find a comparison that shows which MPPT delivers the best charge out of the solar input. The Victron 75/10 or 75/15 is the leader at the moment https://www.victronenergy.com/solar-...llers/mppt7510

Any other panels or MPPT's i should be looking at?

TIA, Steve

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Sounds very similar to a post on another forum so I'll keep out of it this time!

[steve.armitage Find all posts View Profile Close steve.armitage]

What did i miss Leigh - can you point me towards what you're referring to?

I saw your suggestions of solar panel brands http://www.pradopoint.com.au/showthr...r-panel-to-get

What about MPPT's?

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Ok if you didn't post on the other forum it went this way.

There is nor reason you can't use the panels in parallel, series would only be a problem if there isn't any bypass diodes on the panel and most likely there is.

24Ah ours for a 60ltr ARB seems low but if you believe that's correct then your panel needs to produce at least 30Ah, a 120W panel bright sunny day would probably just cover it but won't allow for cloudy day etc, also you can't keep pointing the panel at the sun if its mounted to the roof so I would go for at least 150W, 200W would be better and enough battery capacity for 2 to 3 days, if you not going to drive every day. ember you'll need to park outdoors if your
not going to drive it.

If your going to add panels later then get an mppt that can accept a reasonable high input voltage so you can use the panels in series.

[steve.armitage Find all posts View Profile Close steve.armitage]

I've been trying to find some panels which will fit on the pioneer platform which is 1185mm wide, excluding the curved edges - some of the 100w panels seem perfect at 1100mm x 570mm.

I've been looking at the flexible black panels, as they are only 3mm tall (except for small box) and would be more discrete than then normal silver panels.

An issues i've come across is that a lot of websites state "Do not wire the flexible solar panels in series" - some examples:
http://www.fullforcehunting.com.au/1...r-panel-genera
https://www.vicoffroad.com.au/120w-f...1179.html.html

At the same time, i see blogs/forums where people are using these (or they appear similar) panels in series.

Is there an issue with this kind of panel when wiring them in series, or only in the choice of controller - parallel for PWM and Series or Parallel for MPPT?

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

As long as the panels have bypass diodes in them they should be fine to connect in series, parallel operation shouldn't be problem.

A quick check of Ebay shows some sellers indicating series and parallel is ok, others indicating
as you wrote not to be connected in series or parallel, looking at the wording in the sales and the pictures I would not be surprised if they are the same seller trading under different names or at least being supplied by the same company.

There are plenty of sellers to choose from, if you not sure what your doing then purchase from a seller that indicates connecting them in series is ok.

Flexible panels tend to have high failure rates, when mounting them you'll need to fix them to some sort of paneling to stop them flexing and fluttering, don't just secure them by the edges.