Solar panels

[TissyD]

I am fitting solar panels on our van but getting confused as to which to buy. What is the difference between monocrystaline and polycrystal and which are the best. I will want to run an inverter to charge my mobility scooter.

 

[Exwindsurfer]

Mono ever time

 

[trevskoda]

Make sure you use an MPPT split control unit, 1ah to starter the rest to hab batteries.

 

[Molly 3]

I think mono are a bit smaller for same output , are you going glass or semi flexible etfe are better .now you have downsize your array will be smaller charging a lithiam mobility scooter in a van is not that simple and needs some research , you would need a pure sign wave inverta to run a battery charger charger

 

[TissyD]

Next question please. I am fitting 2 x 115 watt panels, without all the technical jargon, is it best to put them in series or parallel?

 

[Mr and Mrs Tupcox]

Make sure you use an MPPT split control unit, 1ah to starter the rest to hab batteries.
View attachment 59704

These work fantastic had mine 6 months now .

 

[TissyD]

I've got all the bits now just wondering which was the best way of coupling. I have already got a 12 volt panel on the engine battery.

 

[wildebus]

Next question please. I am fitting 2 x 115 watt panels, without all the technical jargon, is it best to put them in series or parallel?

without the technical jargon who knows?

i.e. You need to provide more technical info to get the right answer. e.g. What Solar Controller do you have? What cabling have you got in place from Roof to Controller?

 

[TissyD]

2 x 115w Monocrystalline panels supplied as a kit with upgraded Victron Smart Solar MPPT from Onboard Energy.

This one

 

[wildebus]

2 x 115w Monocrystalline panels supplied as a kit with upgraded Victron Smart Solar MPPT from Onboard Energy.

This one

So the controller will let you cable up either way (that would not be the case with many) and both ways will provide the same harvesting within measureable limits.
Parallel will give better mitigation against the effect of shading on a single panel.
Series will wake up the controller earlier and give a smaller voltage drop on the cabling - but both of those will give minimal benefit.
For a 2 panel system, I'd go parallel.

 

[TissyD]

Thank you.

 

[Terry H]

I've got all the bits now just wondering which was the best way of coupling. I have already got a 12 volt panel on the engine battery.

If you have 2 panels, series with an MPPT controller is the way to go. The controller will drop the voltage to the 12v for your batteries, and up the current available. Even in the rain, I get between 2 and 5 amps charge, but up to 18 amps on a really sunny day running 2 x 120watt panels.

 

[in h]

Series gives a usable output when light levels are low.

Parallel gives better efficiency when light levels are high.

I use series because I want the extra performance when the sun isn't plentiful.

Either can give better performance when partly shaded, depending where the shade is.

Of course, this all presupposes an MPPT controller. Otherwise, you have to use parallel.