Basic Motorhome Solar Help required

[simon4132]

Hi,

I have a motorhome (RV).
It currently has a single solar panel on the roof. I have looked all over it and cannot find any labels showing the power.
The controller is confusing and seems only to show the battery voltage.
That panel is at least 10 years old. It connects directly to the leisure battery.

As it is a motorhome there are 2 batteries, leisure and starter.

I am buying 3 more solar panels - flexible so I can stick them over the cab bed.

Solar specs for new panels
max power 130w
max v 23.08
max current 5.88a

My original plan is to - connect one solar panel to the starter battery through a controller just to make sure that is charged up separately.
Then have 2 of the new solars in series and the existing one in parallel and connect all to an mppt solar controller.
However - controllers seem to want all the solar panels to be the same type.

Should I just leave the existing one as it is and add the 2 new panels as a separate system?
Or should I just mix them up anyway?

Also, i've seen some dual battery controllers - an even better solution would be to have just one controller for the whole lot.

I want to avoid having huge cables going to the battery.

Any ideas / pointers?

Thanks
Simon

 

[Zapper77]

2-130 watt peak solar panels would only top out at 22 amps...if you are lucky. You will need a charge controller. (I'm able to push 3-100 watt panels through my 20 amp mppt at 12v).

Personally I would recycle that 10 year old panel.

 

[simon4132]

2-130 watt peak solar panels would only top out at 22 amps...if you are lucky. You will need a charge controller. (I'm able to push 3-100 watt panels through my 20 amp mppt at 12v).

Personally I would recycle that 10 year old panel.

I think you might be right about getting rid of the 10 year old panel. That is of course another option. I could replace it with one of the new ones.

 

[HRTKD]

I would skip the flexible panels. The quality just isn't there yet. Low watt results, poor longevity.

 

[mikefitz]

Flexible panels bonded to the roof tend to fail within two years. You then have a daunting task of removing them. Sometimes the over heating failure can damage the motorhome roof.
For around 400 watts of panels you need a 30 amp solar controller mppt type, recomended is Victron Smart 100/ 30,
If using multiple panels ensure they are the same.

Panels & Mounts

Suppliers of solar panels and solar kits for caravans, motor homes, boats, farms, homes and businesses.

www.bimblesolar.com

The large domestic types are cost effective.

Victron SmartSolar MPPT Charge Controller 100/30

Victron Smart Solar 100/30 MPPT Charge Controller with Bluetooth built-in. For 12V & 24V systems in motorhomes, caravans, campervans & boats.

www.12voltplanet.co.uk

Suggest you remove the existing panel and its controller.

Don't consider the controllers that offer dual output. For maintaining the engine battery you can fit a battery maintainer.

Votronic 3065 Battery Master - Standby-charger 12V

<p>This Votronic charger is a great way to trickle charge your engine battery in a motorhome, Installed between the starter battery and the leisure...

www.roadpro.co.uk

You have not indicated the type and Ah capacity of the leisure battery. What is the issue about cable size?
Cables need to be selected for the expected current and to be of suitable cross section to keep volt drops to minimum

 

[Vigo]

With roof space at a premium it is likely worth it to replace the old panel with a new one, or put that space 'back into the pool' for the new panels.

I agree don't give the starter battery separate anything at this stage, you can always feed it power post-solar-controller IF there is a need.