Grid connect solar modules for RVs – here’s how you can use them

by | Jul 10, 2020 | Articles, Electrical (general), RV Solar, SRW

by Collyn Rivers

Grid Connect Solar Modules

Using grid connect solar modules for RVs is readily done but needs an MPPT regulator. This article by Collyn Rivers explains how and why it is done.

Grid connect solar modules are often sold very cheaply. Most, however, produce optimum power at voltages that cannot be handled by the 12-24 volt solar regulators used in most RVs. Using grid connect solar modules for RVs is however readily done by using an MPPT (Multiple Power Point Tracking) solar regulator. An MPPT regulator accepts a much wider voltage range. Grid connect solar modules for RVs can also be used in stand-alone solar systems. This article by Collyn Rivers (RV Books) explains how and why.

Grid connect modules are made in a huge range of voltages and sizes. Those of around 300-350 watts tend to be the best value for money. Most output about 50 volts at 60-7 amps.

Juggling volts and amps

An MPPT solar regulator ‘juggles’ incoming volts and amps to produce whatever needed to charge your solar system’s batteries deeply, speedily and safely. For RVs such as camper trailers, caravans and motorhomes this is usually a (nominal) 12 or 24 volts.

Care is needed when buying an MPPT solar regulator when using grid connect solar modules for RVs. Some accept any input voltage from as low as 9.0 volts to often well over 100 volts. But some work only from 9-36 or so volts. Others have an upper limit of about 50 volts. This will be shown in the maker’s literature.

mppt solar regulator for grid connect solar

This 400 watts Morningstar MPPT solar regulator is ideal for smaller systems. It will accept input from solar panels up to a nominal 36 volts. (The maker emphasises its suitability for use with grid-connect solar modules for RVs.) Pic: Morningstar.

MPPT regulators do not need prior setting for incoming solar voltage. They do, however, need setting for the type and voltage of the battery/s used (e.g. lead-acid, AGM, gel cell etc), and usually for the capacity (amp hours). This is usually easy to do. If in doubt ask the vendor (or most girls or boys from 9 upward).

Outback Power MX60 for grid connect solar for rvs

The Australian-designed (now US-made) Outback Power MPPT units will accept up to 110 volts or so at up to 80 amps – ideal for larger systems on motorhomes converted coaches – and home stand-alone systems. Pic: Outback Power.

Can I legally install grid connect solar modules for RVs myself?

In Australia, it is legal for non-electricians to install grid connect solar panels for RVs etc, as long as the solar array’s nominal voltage does not exceed about 65 volts. The peak off-load voltage must be under 120 volts dc. This typically limits solar module output to a (nominal) 72 volts.

You are unlikely to experience other than a tingle up to 24 volts. Care is still needed, particularly if working on the RV’s roof. Anything above 50 volts or so can give quite a shock. Unless experienced in electrical work have someone who is to assist you. If the modules produce, or are series-connected, to produce above 120 volts dc, you must use a licensed electrician.

Be aware that many (probably most) ultra-cheap solar regulators are claimed to be MPPT – when they are not. Stay only with known brands.

Further information

Full details of all this, plus a great deal more is included in my books: Caravan & Motorhome ElectricsSolar That Really Works! and (for bigger systems) Solar Success. See also related articles (under Power/Solar) on this website. My other books are the Camper Trailer Book and the all-new Caravan & Motorhome Book. For information about the author please Click on Bio.

Collyn Rivers is a semi-retired automobile research engineer.  He is the author of seven books, five of which are about making RVs and solar work optimally.

Caravan and Motorhome Electrics

The essential handbook for anyone with an RV of any kind.  Everything you need to know to make the electrics in your rig work for you.

Cover of Caravan and Motorhome Books by Collyn Rivers

eBook versions

Paperback version

The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above.

Any bookshop, whether online or bricks and mortar, can order copies of Caravan & Motorhome Electrics.  Just ask.
ISBN: 978-0-6483190-8-5

Solar Success

Whether you’re building a new home or adding solar to an existing structure, this is the one book you can’t afford to be without.

eBook versions

Paperback version

Any bookshop, whether online or bricks and mortar, can order copies of Solar Success.  Just ask.
ISBN: 978-0-6487945-4-7

Why Caravans Roll Over
and how to prevent it

Explains in detail every aspect of tow vehicle and caravan stability. This is what you need to know to be safe on or off the road.

eBook versions

Paperback version

The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above.

Any bookshop, whether online or bricks and mortar, can order copies of Why Caravans Roll Over.  Just ask.
ISBN: 978-0-6483190-6-1

Solar That Really Works!

Solar that Really Works! covers the design, installation and use of solar in cabins, camper trailers, caravans, fifth wheelers, campervans and motor homes.

eBook versions

Paperback version

The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above.

Any bookshop, whether online or bricks and mortar, can order copies of Solar That Really Works!  Just ask.
ISBN: 978-0-6483190-3-0

The Caravan & Motorhome Book

The Caravan & Motorhome Book covers every conceivable aspect of campervan and motorhome usage. If you own a camper van or motor home, you'll want this book.

eBook versions

Paperback version

The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above.

Any bookshop, whether online or bricks and mortar, can order copies of The Caravan & Motorhome Book. Just ask.
ISBN: 978-0-6483190-5-4.

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Caravan and Motorhome Electrics

The essential handbook for anyone with an RV of any kind.  Everything you need to know to make the electrics in your rig work for you.

Cover of Caravan and Motorhome Books by Collyn Rivers

eBook versions

Paperback version

The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above.

Any bookshop, whether online or bricks and mortar, can order copies of Caravan & Motorhome Electrics.  Just ask.
ISBN: 978-0-6483190-8-5

Solar Success

Whether you’re building a new home or adding solar to an existing structure, this is the one book you can’t afford to be without.

eBook versions

Paperback version

Any bookshop, whether online or bricks and mortar, can order copies of Solar Success.  Just ask.
ISBN: 978-0-6487945-4-7

The Caravan & Motorhome Book

The Caravan & Motorhome Book covers every conceivable aspect of campervan and motorhome usage. If you own a camper van or motor home, you'll want this book.

eBook versions

Paperback version

The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above.

Any bookshop, whether online or bricks and mortar, can order copies of The Caravan & Motorhome Book. Just ask.
ISBN: 978-0-6483190-5-4.

Solar That Really Works!

Solar that Really Works! covers the design, installation and use of solar in cabins, camper trailers, caravans, fifth wheelers, campervans and motor homes.

eBook versions

Paperback version

The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above.

Any bookshop, whether online or bricks and mortar, can order copies of Solar That Really Works!  Just ask.
ISBN: 978-0-6483190-3-0

Why Caravans Roll Over
and how to prevent it

Explains in detail every aspect of tow vehicle and caravan stability. This is what you need to know to be safe on or off the road.

eBook versions

Paperback version

The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above.

Any bookshop, whether online or bricks and mortar, can order copies of Why Caravans Roll Over.  Just ask.
ISBN: 978-0-6483190-6-1