Battery capacity required for cabins and RVs

by | Sep 4, 2018 | Articles, Batteries & Battery Charging, CME

Battery capacity

Solar and battery capacity required for cabins and RVs is usually limited. As with homes and properties, always have maximum solar capacity. Consider using LiFePO4 batteries as 80% of their nominal capacity is available. LiFePO4 batteries are also light and compact. Lead acid and AGMs, however, are fine for converted coaches. For those, size and weight are less critical.

Battery capacity required for cabins and RVs - battery capacity,solar capacity,LiFePO4 batteries,AGM batteries,Dual solar systemThe author’s 2004 4.2 litre TD Nissan Patrol and TVan each had their own self-contained solar system. Pic: rvbooks.com.au/

Cabins and RVs should have the maximum solar capacity feasible. This ensures batteries will charge fast and deeply even with intermittent sun. The battery capacity required for cabins and RVs needs to cope for about three days. From thereon it is cheaper to charge via a grid-voltage charger. This can also be powered via a small inverter/generator. See: RV Solar and Alternator Charging.

As a rough guide, (and assuming a 12-volt system) do not allow battery capacity (in amp hours) to exceed 50% of your solar capacity (in watts). Unless you do, your batteries may not adequately charge. A 100 amp-hour battery thus needs at least 200 watts solar capacity. Seemingly excess solar capacity will assist charging during times of little sun. There is no risk of overcharging. The solar regulator automatically prevents that.

Dual solar system

AGM batteries are ideal for cabins and converted coaches, but their 33 kg per 100 amp-hour (for 12-volt units) is too heavy for small [ifso id=”239224″]. Where size and weight are critical use lithium-iron LiFePO4 batteries. They cost more, but as 80% of their nominal capacity is available, that cancels out their higher price. LiFePO4 batteries are also light and compact. They are about one-third the size and weight of AGMs. Another benefit is that unlike conventional lead-acid batteries, as long as first fully charged. AGMs can be left for up to a year without use. LiFePO4s can be left for evem longer.

If towing a camper trailer or travel trailer consider having a self-contained solar system in each. This enables you to have one (charging) in the sun. The other can be in shade. You can readily interconnect the systems to share power and battery capacity.

Having two self-contained systems enables you to have a small fridge in the tow vehicle. This is very convenient when shopping. That vehicle too, can have a solar array on a roof rack and an associated battery.

Our 4.2-litre Nissan Patrol and TVan (shown above) were set up this way. Each had its own system. Moreover, they could be used separately or paralleled if desired. In over seven years, however, we never needed to do so.

It is also feasible to have alternator charging. : https://rvbooks.com.au/rv-solar-and-alternator-charging/ outlines how.

Our book Solar That Really Works! explains all. Furthermore, our equally top-selling Caravan & Motorhome Electrics tells all you need to know about the electrics generally.

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 travel trailer 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, travel trailers, 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.

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, travel trailers, 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 travel trailer 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