Hobby caravan 12v power

[Steamer]

While I agree that it makes good sense to fully insulate batteries from everything and provide good ventilation to prevent any build up of fumes while charging, but there are literally millions of cars, boats, caravans and motorhomes with batteries that are not in sealed boxes. Here are just a few examples.

This is a photo of a factory fitted leisure battery in an Eriba Triton 420GT:

Under the sofa/bed open to the internal atmosphere.

My old Leyland Mini, the car battery is in the boot, behind the rear seat.

Narrow boat battery bank in back cabin.

Boxed in under the rear step, but not air sealed to the living space.

 

[Damian]

Quote " then can someone please point me towards the written legislation that states this. "

IEE Wiring Regulations : A721.55.3.5

 

[WoodlandsCamper]

I may be cynic, but why do people buy new caravans without the features they want.

 

[Damian]

I may be cynic, but why do people buy new caravans without the features they want.

I often wonder why too.
Many times I am asked to retrofit certain equipment and systems which are readily available in other vans, and the downside to the owner is that retrofitting often costs a lot more than the alternative van.

 

[Steamer]

Over time people's requirements change. Personally, I have no intention of adding a battery to our fairly new van as it was bought for continental site use only, but years ago, I bought an Eriba for UK site use which had no battery (Batteries are optional extras in Eribas) and after 6 years, we decided to use it for rallies where power wasn't available. The need to add 12 volt power became necessary.

Because of the lifespan of Eriba vans being so very long, the needs of owners are likely to change.

 

[Steamer]

A721.55.3.5 Auxiliary battery compartment A tray should be installed under an auxiliary battery if the electrolyte of this battery is liquid. The interior of an auxiliary battery compartment should be ventilated and protected against the corrosive effect of acid-laden gases, either by: (i) installing a sealed auxiliary battery that incorporates an external ventilating kit that is taken to the exterior of the caravan, or (ii) installing an auxiliary battery in an enclosed battery compartment that is protected internally against corrosion and is ventilated to the exterior of the caravan by means of a suitable tube with a minimum inside diameter of 10 mm at the top of the auxiliary battery compartment, in accordance with the battery manufacturer's instructions or as supplied by the manufacturer of the auxiliary battery, or (iii) ventilating the compartment at low level and high level to the exterior of the caravan and constructing the interior of the compartment, including the sides of the ventilator openings, of acid-resistant material or providing it with an anticorrosive finish. If the compartment opens into the interior of the caravan, the lid should provide an air seal. The minimum free area of ventilation should be not less than 80 mm at low level and not less than 80 mm at high level.

Item iii refers to high and low level ventilation as an acceptable option which the BSS recommends as well.

Sealed batteries are more accurately called VRLA as in valve regulated lead acid, they have a pressure operated vent in case of over charging and so theoretically require ventilation although it will never be used in normal conditions. AGM and gel are not considered liquid by transportation companies.

 

[Damian]

I do not know what you are trying to say.
Yes the regs refer to high and low level ventilation, and you highlight one specific part of the paragraph but you fail to include the rest of the sentence.....
..ventilating the compartment at low level and high level to the exterior of the caravan and constructing the interior of the compartment, including the sides of the ventilator openings, of acid-resistant material or providing it with an anticorrosive finish. If the compartment opens into the interior of the caravan, the lid should provide an air seal.

Your assertion of the possible use of the POV on a sealed battery is all very well until there is a problem , then it WILL vent.
Trying to differentiate on the name given to various batteries is just a red herring, apart from GEL units, lead acid batteries are lead acid batteries, nothing more., nothing less.

However, you do what you "think" is right whilst I do the right thing, and it is of no use whatsoever comparing caravans with boats or cars, they have their own regs.
It is not good enough to suggest a course of action which a forum member may use which is potentially dangerous.

 

[ProfJohnL]

I'm not convinced that a leisure battery needs to be in a self contained battery box that needs to be sealed away from the living quarters. I have owned countless professionally built cars, caravans and boats where the batteries are sharing the same space as the occupants. If the rules have changed over the years, then can someone please point me towards the written legislation that states this.

Over time legislation and codes of practice change, usually as the result of some unfortunate incident which has made the industry re-examine the causes of teh incident. There is legal pressure for industries to engineer protection into designs and practices.

The argument that a particular practice has not harmed you, does not mean that others have not been harmed. I recall seeing a film somewhere of a moored boat that did explode, and the cause was traced back to a battery that failed and started to produce hydrogen. A spark ignited the gas resulting in the boat effectively being destroyed by the blast, but also the follow up investigation found that when the explosion occurred it also ruptured the batteries, spraying battery acid around the interior.

It was judged If the boat had been occupied any occupant would most likely have perished as result of the explosion and fire, or at lest been seriously burned by boiling H2SO4.

If the batteries had been properly enclosed and vented, the vapours would have been contained and would not have been explosive (due to the exclusion of air).

I suggest that if you were to purchase a professionally built vehicle now it would have a room sealed battery box.

 

[Steamer]

My point is that there are millions of caravans and motorhomes out there with leisure batteries under seats and beds, not contained in sealed and vented purpose built battery boxes. It is unrealistic to expect these owners to redesign their vans/ vehicles to update to modern manufacturing regulations.
I am not saying that it doesn't make good sense, but the risks are obviously very low otherwise there would be a big effort by the UK government to get everyone into line. Remember the effort when people had to wear seatbelts in vehicles.

I merely suggested that the OP simple buy a leisure battery and hook it up via the 13 pin plug. Rather than leave an expensive battery on the grass outside the van for people to pinch, they simply pop it into the front under bed storage cupboard available on the Hobby 560. Leisure batteries tend to be at risk of gassing during charging and in normal use, this rarely happens. Gel batteries don't gas, so it would have been far easier for someone to recommend this instead.

I was merely trying to suggest a simple, inexpensive option to help someone cope with the odd weekend away on a rally field. This way, there is no major expense, no need to drag a heavy battery around with him on his other trips, just charge up the battery at home before setting off and pop the battery in the car boot.

The risk of explosion is tiny, especially when merely discharging a battery (ie. Not charging it) and if it is a gel battery, no risk at all.

Thanks for pointing out the current regulations that apply to the manufacturers.

Ps. These batteries will change our world. Solid State Sodium batteries. They have 3 times the capacity of Lithium Ion and charge up in a fraction of the time!
They are also cheap to make as they use the salt from sea water.
See how serious Toyota are taking them!
https://www.autoblog.com/2017/07/25/solid-state-batteries-why-toyotas-plans-could-be-a-game-change/

 

[Martin24]

Damian, thank you for trying to make sure that people using the forum stay safe and abide by current regulations. Please any newbie caravan members of the forum and old hats as well take note of what Damian has posted.

 

[Damian]

Quote " Thanks for pointing out the current regulations that apply to the manufacturers "

The regulations do not just apply to manufacturers, they apply to anyone carrying out work on a van which is not of the original build. That is any new item added MUST comply with the current regulations.

Similarly with gas, all work MUST comply with current regulations, for manufacturers and anyone else who does work on that system.

 

[Steamer]

This makes interesting reading; http://batteriesbyfisher.com/agm-batteries

"Do sealed batteries need to be vented?
A VRLA battery (valve-regulated lead–acid battery), more commonly known as a sealed battery or maintenance free battery, is a type of lead-acid rechargeable battery. Due to their construction, they do not require ventilation, can be mounted in any orientation, and do not require constant maintenance."

 

[Dustydog]

Steamer

The answers you have received are from the top technical caravan Gurus we have. I really fail to see why you continue to disagree with them hmy:
Many of us have been tuggers for decades and yes some of our earlier years practices were not safe by today's standards. Now we are all more sensible and safety aware. Why on earth would we want to go backwards and create potential hazards.
Damian summed it up perfectly. You carry on doing the wrong thing but please please don't encourage Newbies on here to do something which imo is very dangerous.

 

[ProfJohnL]

Thank you Dusty,

But in fairness, Steamer has asked a valid question concerning VRLA type batteries.

In the context of caravanning it is very unusual to find owners who are prepared to spend the extra money on VRLA batteries. Power densities of VRLA are generally lower than for wet formulations, so get get the required capacity you wil need more and physically bigger batteries. This has a knock on effect for space and weight which of course is a major concern for caravanners. Consequently the more conventional wet lead acid battery is the norm.

Proper room sealing is required for wet or vented lead acid batteries, and as that is what most caravanners will use, It is sensible to fit the required containment for safety and convenience, and prepared boxes are available. While VRLA batteries may not require ventilation when they are working correctly, but in the event of a cel failure they tend to get very hot, they can distort and break open allowing their content to leak. I do not know for certain but I would guess the gel is just as corrosive as conventional battery electrolyte.

We can't stop you from doing what you want to do, but you have asked questions, and we have provided best practice answers, We have not created the legislation or the codes of practice, but we are duty bound by professional etiquette, to question non conforming ideas and practices.

On this point please do not try to sway us to condone what is considered bad practice.

 

[Steamer]

I feel it is important to question advice given by complete strangers on public forums, especially when this advice uses powerful words like "safety and regulations". As an aeronautical engineer and process manager, I am naturally inquisitive and am required to question those people that claim to be an authority on a particular subject.

Regulations A721.55.3.5 does not appear state that all battery types should be contained within an auxiliary battery compartment, only batteries containing a liquid electrolyte. So gel batteries would be exempt.
A Lithium Ion leisure battery would be exempt too!
https://www.sunstore.co.uk/PowerXtreme-LithiumIon-125ah-battery.html

I was told that these regulations don't just apply to manufacturers, but everyone. After a little digging and according to the Provision of Information within BS 7671 Part 2, Annex A to Section 721 states that DC installations used in caravans do not fall with the requirements and as such, are offered as recommendations only. See below.

It therefore appears that caravan DC installations can vary legally. Furthermore, as we know that in the UK there is no requirement to have caravans MOT tested, so impossible to detect any none conformity even if it became mandatory.

I feel that good advise would be to recommend sealed and ventilated battery boxes or compartments for any liquid electrolyte batteries, but offer alternative battery technologies like Li-ion or gel, if lower power needs are sufficient.

 

[ProfJohnL]

Hello Steamer,

I agree entirely that traditions should be questioned, as they often fail to take into account changes in available information, technology, and social acceptance, and heaven knows caravanning is rife with traditions and assumptions that don't have logical or scientific basis. A tradition should only be allowed to continue providing it is fit for purpose through a vigorous appraisal.

However in the context in 12V wiring systems in caravans, there is legislation (which can often defy logic but we have to comply) and codes of practice that generally have been revised over time with the latest best practice. And whilst it is true there are special provisions that exempt privately owned touring caravan and self propelled motorhomes form certain aspects of some regulations, there is still the overarching requirement that works carried out in these vehicles must be safe, and not present a hazard to the owners or users or other persons.

Just because the likelihood of detection of nonconforming works is very low, it is not impossible, and if an incident arrises where the nonconforming works are implicated in the cause or as an uncontrolled hazard the HSE could still prosecute.

As an aeronautical engineer you above all should appreciate the that when a recommendation is made through a recognised body (for example the CAA or IEEE or for caravans the NCC) it would be frowned upon if those recommendations are not followed.

Let me take you back to your first post in this thread #441028

You specifically refer to a "leisure battery" and that in the context of caravanning is a wet lead acid construction. The subsequent advice that was given was wholly commensurate with that technology.

I fully recognise that battery technology is advancing very quickly, and I hope that some of the newer high power density systems prove to be durable and light weight but currently (no pun intended) there is no financially practical alternative to the wet technology for caravans.

 

[Steamer]

I concur. Great summary.