Leisure battery and car battery in parallel?

[wednesday_rose]

Hi guys
So, since you all helped me out with my power problems, everything has been go, go, go! :lol:
As you would expect, the more experience you get, the more thoughts come to mind.
Unfortunately my van is running off a car battery so I'm looking into getting a nice 120/130AH Leisure battery.
(also found out about power inverters :lol: Nice prices on ebay for 1500W (3000W peak) inverters)
Anyway, I had already considered getting a second battery, securing it in the gas bottle compartment at the front and hooking it up parallel with the other battery.
So, I'm going to get a leisure battery, which will be my main battery, but, can anyone tell me if I can hook that one up to a car battery in parallel? Are these two types of batteries compatible with each other?
If so, is it really that bad if the leisure battery is stronger than the car battery?
Looking forward to hearing your thoughts.
Kenny

 

[wednesday_rose]

Sorry, I've posted this in the wrong part of the forum

 

[Damian]

Topic moved for you.

As far as putting a battery in the gas locker, it is NOT allowed under any circumstances.

You must either get a battery box fitted to the van , or (but not recommended) fit a battery box inside the van under one of the seats but it MUST be a purpose made box and vented to the outside.

 

[wednesday_rose]

Thanks for moving my post.
Okay. I didn't know that you cant put the battery in the gas bottle compartment, so thanks for that.
I don't really want to put the battery inside the van.
I think I'll just forget about the idea.
I've been thinking though, the car battery is a 95Ah battery and I've found a 135Ah leisure battery, the batteries don't need to be connected all the time. If we go wild, I can just hook them up when we get there and stash the battery under the van.

 

[WoodlandsCamper]

Check to see if the 135Ah battery will fit into the battery box. The bigger the power the bigger the physical size generally.

 

[bertieboy1]

If the battery box installed and fitted by the caravan manufacturer is not vented to the outside is it not purpose made.

 

[wednesday_rose]

Yes. It was installed by the manufacturer and is vented, just not big enough to take 2 batteries.

 

[WoodlandsCamper]

just not big enough to take 2 batteries.

No battery box ever is because caravans are not designed to cater for 2 batteries. You could take 2 batteries and only use one at a time whilst the other is on external charge elsewhere.

 

[bertieboy1]

The battery box on my caravan is certainly not vented to the outside,I've never seen one fitted with external vents.In fact the box is sealed from the outside.

 

[Damian]

All fitted battery boxes have a small cut out in the moulding where the mains cable fits when connected to the mains and the locker door is shut.
It is this depression that provides the venting.!!!

 

[WoodlandsCamper]

But isn't there a wall and seal between the 240V side of the battery box and the battery area?

 

[Damian]

Yes but its not gas tight !

 

[JTQ]

My last two continental caravans and some motor homes I have been interested in buying recently have their habitation batteries within the van, without external vents and simply strapped down not in special battery boxes.

These were as factory built and fitted.

There is no "must" to having a special enclosure and venting requirement, just the choice of the right technology lead acid battery and matching charging system to enable doing without.

It is certainly not wise to use conventional unsealed batteries without external venting.

 

[Albatros]

Not sure about your question but would reccomend you get an AGM battery, they are bit more expensive BUT you are getting a superior product over lead/acid. No hydrogen discharge, and they stand up to being stood and deep discharge 10x better than alternative, cant reccomend high enough

 

[JTQ]

This company has some views on our type of batteries. Makes interesting reading:

Moderator Note: Link to caravan service company removed as per forum rules.

 

[ProfJohnL]

This company has some views on our type of batteries. Makes interesting reading:

Thanks JTQ,

I have no connection with this company but I do like the way they present heir web site, and the comments they make regarding how they view their obligations to customers. If they follow their stated aims then more power to their elbows.

I do note that they have a page relating to motor movers:-

and its interesting the conclusion they come to regarding the type of battery required. There have been a couple of recent threads about batteries only for movers, and this companies perspective and logical approach concurs with my own.

Moderator Note: Link to caravan service company removed as per forum rules.

 

[JTQ]

This company has some views on our type of batteries. Makes interesting reading:

Moderator Note: Link to caravan service company removed as per forum rules.

I am sure you are right and there probably is some rule, but unfortunately, this is a case where the rules do no service to the forum's readers, precisely the opposite. You may like to ask that company if you could reproduce their article unaccredited as I am sure it would help many here better understand the complex issues with our batteries?

 

[Damian]

I have looked at the website and have the following points to make:
1. They do NOT sell batteries.
2. They do NOT repair motor movers
3. They are NOT the mover manufacturer.
4. They have no more technical information available than the motor mover makers, nor are they more qualified.

They are simply a caravan service provider with their own take on what is considered to be a suitable battery.

 

[chrisn7]

When looking at leisure batteries, it seems there is not a linear relationship between capacity and weight.There seems to be a significant change in construction around the 110amp size, so anything less is disproportionately lighter, so you might want to consider if a larger battery is really worth the significant increase in weight

 

[saint-spoon]

Can I point out that there is a marked difference between the design and construction of car batteries and leisure batteries. Car batteries are designed for short high current usage when the car is started whereas leisure batteries are designed to have a long low current discharge. If you put a leisure battery into a car you will most likely destroy the battery quite quickly as the internal plates distort during high current take off, with car batteries in leisure usage the coatings on the battery plates break down in lead acid batteries if they are repeatedly drained over extended periods (same as happens if you leave your lights on and deaden the battery that way.
If nothing else I would recommend changing your current car battery for a leisure one; you will see a marked improvement in performance.

 

[ProfJohnL]

Can I point out that there is a marked difference between the design and construction of car batteries and leisure batteries. Car batteries are designed for short high current usage when the car is started whereas leisure batteries are designed to have a long low current discharge. If you put a leisure battery into a car you will most likely destroy the battery quite quickly as the internal plates distort during high current take off, with car batteries in leisure usage the coatings on the battery plates break down in lead acid batteries if they are repeatedly drained over extended periods (same as happens if you leave your lights on and deaden the battery that way.
If nothing else I would recommend changing your current car battery for a leisure one; you will see a marked improvement in performance.

These were exactly the points that JTQ and I tried to make by pointing to some information pages on a web site that Damian deemed to be advertising.

 

[JTQ]

These were exactly the points that JTQ and I tried to make by pointing to some information pages on a web site that Damian deemed to be advertising.

Sadly, they were summarily judged as “less qualified and having no more technical information” on batteries, because “they did not sell batteries or make or repair movers”. What was missed out in that statement was they are supplies and refurbishes of caravan, motorhome and leisure craft electronic controller charger units.

I had simply stated “This company has some views on our type of batteries. Makes interesting reading:” a view I still maintain. One that could help many of our readers at least consider the arguments involved on this subject, probably more soundly that asking a sales person in a caravan accessory shop that sells batteries and movers, awnings, water fittings, LEDs etc.

 

[Damian]

Quote " What was missed out in that statement was they are supplies and refurbishes of caravan, motorhome and leisure craft electronic controller charger units."

They are simply one of several companies who do exactly the same.

 

[JamesH]

A simple question. If I used this company to repair my caravan battery charger, for instance, and received excellent service at a very keen price could I recommend them on this forum ?

 

[ProfJohnL]

Quote " What was missed out in that statement was they are supplies and refurbishes of caravan, motorhome and leisure craft electronic controller charger units."

They are simply one of several companies who do exactly the same.

Hello Damian,
I do object to the removal of the web page addresses you carried out earlier in this thread.

You stated you removed them because advertising is not permitted, yet the subject was batteries and as the authors point out they do not sell batteries so apart from naming the company, there was no commercial benefit they would gain. The fact is the pages contained some well argued points about the types of batteries recommended for caravans, and it went on to describe a new technology that overcomes some of the short comings of the traditional Leisure batteries and cranking batteries. This is of real interest to caravanners.

As for them having less experience than mover manufacturers, I think that is being very presumptuous. Mover manufacturers are only likely to have researched batteries from the perspective of movers, Where as a business who deals with a wide range of automotive issues are likely to have a much broader knowledge of what's available and how they will perform.

Now lets look at issue of the other businesses that do sell products that are openly mentioned in the forum without censure. Ironically Caravan Manufacturers, Gas suppliers, Appliance and equipment manufacturers, Battery manufacturers and sellers, service companies, Caravan sites and caravan clubs etc. These are all commercial organisations who might benefit as a result of being mentioned in the forum!

Perhaps you should be promoting a more even handed approach and removing reference to all these other organisations?. Or lets be more realistic? Yes it can be a fine line between spreading information and advertising, but even that bastion of broadcasting balance the BBC sometimes cannot avoid mentioning commercial organisations when dealing with a topical issue.