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Leisure Batteries

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peridot
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Leisure Batteries

Post by peridot on Wed 13 Mar 2013, 9:48 pm

The 'Noseweight' thread had drifted into matters electrical so I thought it appropriate to start a new one.

I had been considering the addition of a 110 Ah battery to power a motor mover and provide for off-EHU camping and was thinking about the best place to locate it in the Destiny.

As to the battery itself, given that many of the claims made for particular makes of battery are specious to say the least, and the fact that I am on a tight budget, I was planning to go for a 'cheap and cheerful' type.

I was just about to buy a Numax one from Tanya.co.uk when a bit more Googling took me to [You must be registered and logged in to see this link.]

They had a Bosch L4 018 advertised at £85 - not much more than the Numax. I gave them a call and it turns out that the batteries listed on their website are actually out of date and no longer available. However they had the newer Bosch L4 033 105Ah available at £87.50 delivered.

This doesn't appear to be widely available under the Bosch brand in the UK (I understand that Car Batteries Online import directly from the Bosch manufacturing plant). It is however identical to the Varta LFS105 which is over £143 delivered from Tanya

From what I've read up on it does seem that the Bosch/Varta batteries are genuinely better constructed than the generic types and can withstand deeper discharge giving more useable capacity. I'm certainly very happy with the price.

I'll report further when the battery arrives and I get around to installing it.

WARNING: Anyone thinking about ordering from carbatteriesonline please read from post 35 onwards (page 3). One of our members reports a very poor experience with this company and their website appears to continue to offer batteries that are not available.



Last edited by peridot on Tue 30 Apr 2013, 11:07 pm; edited 1 time in total
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peridot
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Re: Leisure Batteries

Post by peridot on Fri 15 Mar 2013, 10:04 pm


Despite not promising next day delivery the battery did in fact arrive today.

Carefully and professionally packaged in a custom fit shock absorption 'pillow'.

It won't win any beauty contests - which is only right for a battery Smile


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navver

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Re: Leisure Batteries

Post by navver on Fri 15 Mar 2013, 10:28 pm

I think I paid £85 for a Numax 110AH 3 years ago and it's on it's last legs now. I think the life depends a lot on the charging regime. I have to keep it at a storage site in the middle of a muddy farm so not easy to get to and because the battery is such a fiddle to get in and out of the compartment I tend to leave it there. I wish I could keep it at home and charge it regularly.

I must admit yours looks very nice for a battery. Nice sexy ruby red terminal post. Be interesting if you post again in 4 years if it's still going strong.
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peridot
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Re: Leisure Batteries

Post by peridot on Fri 15 Mar 2013, 10:45 pm

That's one of the problems with getting reliable feedback on batteries - unless you have a real dud it's a few years before you know whether the more expensive ones are really any better.

Three years from a Numax that you haven't been able to look after particularly well doesn't sound too bad.

Unfortunately the red terminal is just a plastic protective cap. I have however ordered some sexy colour coded terminals for it Cool

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Helen
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Re: Leisure Batteries

Post by Helen on Sat 16 Mar 2013, 8:31 am

This is our battery, we've been using this one since buying the Dandy, I think the reason it's lasted so long is because it's charged regularly and the charging box that the Dandy came with makes it easy to do.

Not sure on the make but will get the other half to take a look when he gets home

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peridot
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Re: Leisure Batteries

Post by peridot on Sat 16 Mar 2013, 8:52 am


The Lab-Craft was (and is) a superb piece of kit that has looked after many a battery.

Very hard to get hold of one now.

I remember it was my Dad's pride and joy when he first got one and I build him a split charging unit from scratch to charge the battery in the boot of the car. Thinking about it that unit may well be in a box of junk in the garage at my parent's house, I must have a dig around when I'm next over. It was better than the micro-miniature one I've just fitted to my car.



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Tow Itch
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Re: Leisure Batteries

Post by Tow Itch on Sun 17 Mar 2013, 9:05 pm

Ah the lab craft. Thought I'd recently refered to these myself but searched using the search function and can find nothing.

Battery charging. I have a number of questions re battery charging both charging from the mains, well from the mains through a charging unit and also questions over using a split charger or similar from your car.

Charging From The Car

At the tail end of a PM the other day received a question:
could you tell me the system I need to charge up the battery's when I drive I remember you told me about it on a post but can't find it thank you

Reply being:
What you want is a split charge relay. Also unless you have some perverse desire to wire up this relay to the alternator a Self Sensing Split Charge Relay is what you want.
Now normally the person fitting your tow bar is the person you entrust this to. Unless you had a modern can bus wired car especially if it had an electronic stability programme.
Now xx xxxx xx xxxxx xx (personal detail removed) am I right to guess the fridge and battery will reside in the boot?
This allows the battery to be charged during day driving. Though you may want the space given by locating the battery in the Dandy.
Simple facts and FAQ [You must be registered and logged in to see this link.]

Locating both the battery and the fridge within the car saves on installing a 12s plus. Though I don't know if as you are fitting a new bar if you are choosing that or even a 13 pin assembly. Who knows you could be seduced in to caravans at any point.
The relays are available from under £20 but I might ask for a decent Brand like DURITE. I was going to link their site but the only self sensing relay I could see tripped at too low a voltage. What you want is on at 13.3v or even 13.5v and off at 12.8v or even 13.0v. I've seen suitable on eBay. You probably only need 20 or 30 amp switching but a good brand 140amp relay will last. There is junk being sold as 200amp relays that you would barely want switching your headlights. Ignore above found the relay on Durite's site

[You must be registered and logged in to see this link.] item 0-727-33

What I don't understand is that it looks like a single switched output but if you look at this wiring diagram below:
The bottom diagram. It looks likes the relay will switch the Leisure battery off/on charge and switch off/on the fridge at the same time. And "caravan" power. NA in your case.
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You want the fridge isolated from the leisure battery at the point you switch the engine off otherwise your newly charged battery is trashed by the fridge in 1 hour or so.
So isolated feeds like this are needed.
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Who ever is doing this will know what they're doing. Basic rules fuses on in and out side get shown where they are. Nice thick wire. The more thick wire you see the better. Where is he taking his permanent 12v feed from? A somewhere close to engine bay with nice thick wire, not off some 3 strand wire in the boot (because it's close)

So not having physically done this myself I have several questions as I was trying to go through the process within my head. N.B. I realise for you the options will differ slightly as your unit has the fridge on board and most probably the battery on board. (sh*t I can't remember are you the battery required for a motor mover or is that someone else?) So you will be using 12s, or is it you who is wiring to 13pin

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So looking at the above are most split charge relays fitted with multiple live feeds like this -> [You must be registered and logged in to see this image.]

Or are the fridge and other power just activated from another switched live feed within the car? (thinking while writing) No the essence of the relay is to relieve power on other wiring and save vehicle battery charging in case of problems. Though I do have some issues on the No4 pin (green) other caravan power.
I've seen wiring diagrams with the No4 Supply being an unswitched supply straight from the vehicle battery. Though this will not apply to Dandys are not live feeds other than the battery charging and fridge actually switched off when the engine is running on newer vehicles as other feeds could interfere with car electronic systems?
Though on a 12s system is that what this is doing. I'm not understanding what points are energised when with this relay system.

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Before we go onto charging from mains I wish to return to the Durite pdf page [You must be registered and logged in to see this link.] I presume the second item. The electronic split charger is used for long running engines or larger battery banks. The sort of assembly seen on either a large motorhome or a canal boat?

Charging from Mains

I'm not too fond of Zig units they only charge to 13.8 V you may think 13.8 is great as it's more than the output voltage of a battery but the rate of charge is governed by the difference between the battery voltage and the charger voltage. So zig units not only don't fully charge they are also slow at getting to the charge level that they will put into the battery.
But I know even less about mains charging than I do about alternator charging. I have at times known more just at this point taking help from others is quicker than writing to various battery sages.

The issues loosely covered in [You must be registered and logged in to see this link.] The first bit only as this is actually about charging from alternators and includes things like the voltage drop across a diode that we might have chosen to discuss above but isn't relevant here we're just looking at the necessary voltage to charge fully.
Also here [You must be registered and logged in to see this link.]

My thoughts on charging the battery while away would be:

If you are using an EHU all the time why are you using a battery? Even if you use a motor mover does no one do a remote power option where you can start your car and run a lead from there?

I didn't know that large amperage "smart" chargers were available. For most users with a limited residency on a site I'd use large dumb charger and run a few hours on a high charge then revert to a low charge. When home I'd leave the battery connected or regularly connect to an "intelligent" charger.

Large amperage "intelligent" chargers. So I now know these exist and theoretically everything is perfect if my battery is connected to one of these. What happens when the battery is not just being charged but connected to a consuming drain. Lights, TV, cold box? What does the charger/transformer "see",how does it affect it's supply and how does that affect battery charging or drain. Obviously if the demand was more than the amperage of the charger there would be drain but when charging does the demand nature be it resistive, inductive or a mix affect the charger output?

Finally price sensitivity. If the most perfect answer is twenty times more expensive than the next best and delivers only a marginal improvement then it's not worth bothering.

Not mentioned solar or wind charging but feel free to go into either or both if so inclined.

I await the thoughts of brighter contributors.


Last edited by Tow Itch on Mon 18 Mar 2013, 11:26 am; edited 1 time in total (Reason for editing : Changed 7s to 12s. It's a 7 pin system but called 12s I must have had a moment.)
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peridot
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Re: Leisure Batteries

Post by peridot on Mon 18 Mar 2013, 8:43 am

It's been some years since I did any significant tinkering with caravan / tow car electrics. It was always a minefield and has become more of one over time. When I learned most of what I know the standard colour code was blue positive, white negative. I know it went through a few changes since but now I come back to blue negative, light grey positive - that does make me double and triple check all my connections I can tell you Smile

Anyway, back on topic. The main confusion seems to be around the use of the 12S Pin 2. Pin 2 was always the 12V feed from the car to the trailer going back to the original 12N socket specification before the fog light pinched it.

It appears that use of Pin 2 for battery charging was carried over to the 12S socket but only as custom and practice - not as a defined standard.

Subsequently a standard was defined that mandated 12S Pin 4 as the batty charging feed. This was previously a permanent 12V feed that now needed to be ignition fed.

Not surprisingly the use of Pin 2 for battery charging continued well past the publication of the standard and is still being referenced in technical literature including the diagrams you have included above.

So, to correctly wire a 12S socket Pin 2 should be left unconnected, Pin 4 should carry an ignition-controlled battery charging supply, and Pin 6 should carry an ignition-controlled fridge supply.

Of course that's not going to be much use if your trailer is expecting its battery charging supply on Pin2. You will need to change the trailer wiring, or wire the 12S socket 'incorrectly'.

To add confusion manufacturers of split charge relays, such as the TEC3M you have shown, encourage the use of Pin 2 as a parallel connection to help overcome the overheating / voltage drop problems associated with the fact that the wires in the multicore cables are smaller than they should be.

In the picture you have shown, the two 12v connections are common (just allowing the use of two parallel supply cables). Terminal 6 and Terminal 4 are switched through separate relays to control the fridge and battery charging respectively. Terminal 2 is connected internally to Terminal 4. This provides for the use of a parallel connection using both pins, or caters for a trailer that is wired to accept the battery charging supply on Pin 2 only.

I assume this is also the case in the two schematic diagrams you have shown i.e., once the relays detect 'engine running' the 12V supply is provided to Pins 2, 4, & 6 covering all bases.

To be fully compliant with the standard, caravan manufacturers should ground the 12S Pin 2 at the caravan end. The tow car can then detect this when the caravan is attached and adjust any electronic vehicle systems accordingly. It is perhaps fortunate that manufacturers have chosen to ignore this part of the standard as, for most tow car wiring, it would provide a direct short circuit on the high-current 12V feed.

As far as the 13 Pin arrangement goes, it appears that everyone is adhering to a single standard so hopefully it will sort this mess out in due course.


I still need to update my knowledge and understanding of mains charging systems and would also welcome contributions and links from others. My current belief is that the common 3-stage 'smart' chargers do a good job (although I have the same question over how they react to loads applied to the battery whilst it is charging). They are certainly superior to the 13.8V limited chargers.

I'm not convinced that the chemistry in lead-acid batteries is sophisticated enough to warrant expensive equipment such as the 8-stage chargers I have seen.

I'm not sure either that using a car supply for a motor mover would be a viable proposition. The current demand would probably dictate a 25 sq mm cable connection, which would be rather unwieldy and would probably overload the charging system of most cars.

To recap on my own situation. I've installed 13-pin electrics on the car and converted the Dandy to 13-pin also, although I haven't connected the fridge / battery charging supplies pending examination of the internal wiring on the Dandy when it's next erected.

I've bought the leisure battery which I intend relocating from the front box to the cupboard under the sink.

I've installed a Powrtouch Evolution motor mover, with a temporary electrical connection to the front box, pending final installation of the control box next to the leisure battery.

I'm happy to be corrected on any of the above, it's just a summary of what I've found out from various sources in recent weeks and may not be the whole story.




navver

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Re: Leisure Batteries

Post by navver on Mon 18 Mar 2013, 3:43 pm

As far as I understand there should be a permanant live feed to the dandy and a separate feed from a voltage sensing relay. In the dandy there should be a habitation relay which is changeover upon voltage sensing.

The permanant live feed goes to the habitation relay. With engine running, habitation relay switches power to dandy battery for charging. With engine stopped, habitation relay isolates dandy battery and switches power to dandy low volt circuits so lights etc run from car battery, should the dandy battery run low. With 13 pin socket unplugged from car dandy battery switches power to dandy low volt circuits so lights etc run from dandy battery.

Fridge 12V comes from a seperate pin on the 13pin socket. The feed to this is via a voltage sensing relay in the car so is only live when the engine is running.

The fridge & dandy battery are never connected at any time, as the fridge only uses 12V from the car whilst engine is running and is not connected to the dandy 12V circuits or battery. It will connect to the 12V circuits for control purposes only when running on gas if needed but that will only draw a very small current. The mains 240V fridge supply is to a heating element of about 120W, 0.5A at mains voltage but 10A at 12V.

Volt drop for 2.5mm2 cable is 18mV/Amp/m so at 10A for 5m cable VD is 0.9V, so the battery charging current when driving is always going to be very low. The car battery is at the front with a huge cable connected and the battery in the boot or in the dandy will get much less.
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Tow Itch
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Re: Leisure Batteries

Post by Tow Itch on Mon 18 Mar 2013, 5:26 pm

Ah yes wiring practice has changed and I knew this at one point however when trying to remember or find diagrams I'd used originally I'm at a loss.

Line by line critique of your response not to be critical but so we either "sing off the same hymn sheet" or know the points we have to check out. (Mind you readers we could both be wrong)

Anyway, back on topic. The main confusion seems to be around the use of the 12S Pin 2. Pin 2 was always the 12V feed from the car to the trailer going back to the original 12N socket specification before the fog light pinched it
OK don't know about any 12N practice pre dating fog lamps
Anyway, back on topic. The main confusion seems to be around the use of the 12S Pin 2. Pin 2 was always the 12V feed from the car to the trailer going back to the original 12N socket specification before the fog light pinched it.

It appears that use of Pin 2 for battery charging was carried over to the 12S socket but only as custom and practice - not as a defined standard.
Subsequently a standard was defined that mandated 12S Pin 4 as the batty charging feed. This was previously a permanent 12V feed that now needed to be ignition fed.
Not surprisingly the use of Pin 2 for battery charging continued well past the publication of the standard and is still being referenced in technical literature including the diagrams you have included above.
As stated failing to find diagrams I've looked at previously but have used the same source for all these diagrams as he is quite encyclopaedic and I've used him for coupling info. 1983 wiring as per Thomson Caravans.
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Almost as per up to up to date with a permanent live pin 4 auxiliary caravan, ignition activated pin 6 fridge and alternator or charge light activated pin 2 leisure battery charge. With the only difference being pin 7 left spare resulting in pin 3 earth burn out.

Right so let's go to their 1998 wiring [You must be registered and logged in to see this link.]
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So we can see your removal of the use of pin 2 here and subsequently below even if there is disagreement over 1998 or 1999.
[You must be registered and logged in to see this link.] Sorry no image of the diagram to lift.
So now pin 4 serves as both a connection for battery charging and auxiliary wiring (lights radio etc). Well no wonder this didn't catch on there is no possibility of a good result. A true what genius thought of this moment.
If you connect up to a car as previously wired the first time you stop with a non fully charged leisure battery you don't move again because it's drained the starter battery. So if instead the pin 4 is now on a switched supply be it alternator or ignition key. If for some reason you want to power the caravan (Dandy well it doesn't really apply to us) off the car the engine has to be running or the keys must be in the ignition. That is ignoring the disappointment felt if your battery was wired to pin 2.
If I were to wire up a caravan 12s connection I would not adopt this system ever. Much better to add a missing pin 2 connection.
Ironically I do now believe that the requirement on modern wiring systems is that only the fridge and battery may be powered (Of course road lights as well but that is the 12N) whilst on the move any auxiliary power supply as per pin 4 must disconnect upon either the ignition key being turned or upon the engine running. This is to prevent interference with car borne electronic systems.
To add confusion manufacturers of split charge relays, such as the TEC3M you have shown, encourage the use of Pin 2 as a parallel connection to help overcome the overheating / voltage drop problems associated with the fact that the wires in the multicore cables are smaller than they should be.
As long as the fridge was wired to pin 6 there shouldn't be that much extra current through pin 4 compared to the previous current through pin 2. The major burnout was always through pin 3 if pin 7 had not been wired to earth. Could the encouragement to wire through pin 2 not just have been because only wiring through pins 6 and 4 sucked and everone could see this?
Later saw this
What about pin 4?
Modern caravans have their own relay switch. When the vehicle’s engine is running the power is switched from the interior lights to allow the caravan’s own battery to charge.
from [You must be registered and logged in to see this link.] Still treat pin 4 and 6 only wiring as dubious.

In the picture you have shown, the two 12v connections are common (just allowing the use of two parallel supply cables). Terminal 6 and Terminal 4 are switched through separate relays to control the fridge and battery charging respectively. Terminal 2 is connected internally to Terminal 4. This provides for the use of a parallel connection using both pins, or caters for a trailer that is wired to accept the battery charging supply on Pin 2 only.
I assume this is also the case in the two schematic diagrams you have shown i.e., once the relays detect 'engine running' the 12V supply is provided to Pins 2, 4, & 6 covering all bases.

Ah Um, Ah Um Ah. This is where I start to get stuck. I think the 1st diagram is poor as it shows nothing of how the three 12v +ve supplies are wired within the self sensing device.
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As you're going into the detail of telling me that terminal 2 is wired to terminal 4 I presume you are referring to the 3rd diagram or 2nd wiring diagram.
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To reiterate. I don't understand the nature of how the relay in the 2nd wiring diagram energises the supply pins. what I originally wrote:
I've seen wiring diagrams with the No4 Supply being an unswitched supply straight from the vehicle battery. Though this will not apply to Dandys are not live feeds other than the battery charging and fridge actually switched off when the engine is running on newer vehicles as other feeds could interfere with car electronic systems?
Though on a 12s system is that what this is doing. I'm not understanding what points are energised when with this relay system.
For all I know the pin 4 could be energised upon ignition or it could be of a modern standard and deactivated upon ignition.
I can understand a relay when given an illustration of the internal switching but not just from a representation of the pins as above. Sorry for my numptyism.

To be fully compliant with the standard, caravan manufacturers should ground the 12S Pin 2 at the caravan end. The tow car can then detect this when the caravan is attached and adjust any electronic vehicle systems accordingly. It is perhaps fortunate that manufacturers have chosen to ignore this part of the standard as, for most tow car wiring, it would provide a direct short circuit on the high-current 12V feed.
1) This is beyond me and I'd never heard of it at all. Can you provide a link to this standard?
2) I can see why earting pin 2 on a caravan might result in misery if it's wired to a supply on a split charge relay.
3 I've seen pin 5 described as a spare or the loose term of sensing be it reversing or other. But we are talking of pin 2 wired to "ground" to allow the car to sense this. The issues I can see even if everything was wired to this standard:
a) You are speaking specifically of "Grounding On The Caravan" from pin 2 not a caravan side connection to pin 3 (or 7)How does the car sense being grounded to the caravan there is no return except a variable one of indeterminate resistance across the tow hitch itself? This looks strange to me. It is to pin 3 and was often taken from pin 5 See Bugger Bugger Bugger at the end.
b)With reference to [You must be registered and logged in to see this link.] OK I know it's 16th edition and we're on 17th but it's the only prescriptive piece I could find. The mains earth is grounded but all 12v (ELV) cabling is isolated. From the above
Where 240 V and extra-low voltage circuits (usually 12 V) are both used, the cables of the two systems must be run separately and must both be insulated for 240 V.
. Now a grounded wire from pin 2 would become disconnected when the 12s plug was removed from the car (other than in the bizzare Dandy set ups where the 12s plug is inserted into a second 12S socket in the dandys body to energise the 12v sockets from a transformer or the leisure battery)but this has got to be contrary to the spirit of the 16th edition and with a non specified sensor would possibly (probably) breach the regulations if one connected mains while still attached to the car with the 12S plug?

Allied question relating to mains charging springing from point 3b) So the 12v (ELV) system must be isolated from the 240v supply?
If so how are the transformers of battery chargers wired, are they isolating transformers or are they wired with a common earth potential? If the latter then the 12v (ELV) system is not isolated. Do we have to take care of the type of charger we use? I'm not pretending even 5% of caravanner's would get this but it's a dotting our i's and crossing t's type point.

I'll go with you on the mains charging or to be truthful I know nothing better. Didn't realise the sort of lead thickness a mover would require from a third party source. 252mm is a bit thick.

See you have not ventured to wind or solar charging yet. Perhaps as well.

Decided to have a look at 13 pin wiring and saw that while you now have 3 earths that pin 9 has now become similar to pin 4 as in it is permanently live. It's switching between auxiliary functions and fridge being reliant on the battery charging circuit. I still have a belief about the auxiliary functions not being available whist driving I wonder if I'm mixing these up? With this set up if you did not have a battery would you then need to wire the fridge to pin 10? See Bugger Bugger Bugger.

You kill yourself trying to find a well written guide then after you have written all of the above you find one.Bugger Bugger Bugger

Third parties if you can help please do so this is not meant to be a 2 person conversation. If you don't understand a bit do say, this needs to be easily readable eventually.
The only thing I would be cross at is an opinion without any supporting evidence (and probably only then if it were silly or meant to troll) I don't want the sort of rubbish that you see if you go to UK Campsite and search "Reverse Polarity" [You must be registered and logged in to see this link.] where correspondants are either trolling or so thick their death would be no loss to the gene pool.
I know it has limited interest but all this does take a while to write.
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Tow Itch
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Re: Leisure Batteries

Post by Tow Itch on Mon 18 Mar 2013, 5:59 pm

navver wrote:As far as I understand there should be a permanant live feed to the dandy and a separate feed from a voltage sensing relay. In the dandy there should be a habitation relay which is changeover upon voltage sensing.

The permanant live feed goes to the habitation relay. With engine running, habitation relay switches power to dandy battery for charging. With engine stopped, habitation relay isolates dandy battery and switches power to dandy low volt circuits so lights etc run from car battery, should the dandy battery run low. With 13 pin socket unplugged from car dandy battery switches power to dandy low volt circuits so lights etc run from dandy battery.

Fridge 12V comes from a seperate pin on the 13pin socket. The feed to this is via a voltage sensing relay in the car so is only live when the engine is running.

The fridge & dandy battery are never connected at any time, as the fridge only uses 12V from the car whilst engine is running and is not connected to the dandy 12V circuits or battery. It will connect to the 12V circuits for control purposes only when running on gas if needed but that will only draw a very small current. The mains 240V fridge supply is to a heating element of about 120W, 0.5A at mains voltage but 10A at 12V.

Volt drop for 2.5mm2 cable is 18mV/Amp/m so at 10A for 5m cable VD is 0.9V, so the battery charging current when driving is always going to be very low. The car battery is at the front with a huge cable connected and the battery in the boot or in the dandy will get much less.

navver if you can avoid losing the will to live please read my piece above.

Fridge 12V comes from a seperate pin on the 13pin socket. The feed to this is via a voltage sensing relay in the car so is only live when the engine is running.

The fridge & dandy battery are never connected at any time, as the fridge only uses 12V from the car whilst engine is running and is not connected to the dandy 12V circuits or battery. It will connect to the 12V circuits for control purposes only when running on gas if needed but that will only draw a very small current. The mains 240V fridge supply is to a heating element of about 120W, 0.5A at mains voltage but 10A at 12V.
If using a 13 pin set up then the battery is on a voltage sensitive supply on pin 10. pin 9 supplies both the auxiliary supply and the fridge switching between the two dependant on either switching within the Dandy (caravan) or external switching dependant on alternator output. (See change in use of pin4 on 12S connections) If you were dependant on internal switching either system sensing has moved on a battery needs to be in place supplied by pin 10 or the fridge needs connecting to pin 10.

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Sorry navver it looks like it can be either or.
Some diagrams show auxiliary and battery on pin 9 fridge on pin 10 some auxiliary and fridge on pin 9 and battery on pin 10. The PDF from the Caravan club is the opposite of the pin 9 & 10 arrangement in the above diagram.

The fridge & dandy battery are never connected at any time
Er I think I know what you mean but safer to say the battery never supplies power to the fridge. Connected could be interpreted in several ways.

navver

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Re: Leisure Batteries

Post by navver on Mon 18 Mar 2013, 11:01 pm

I think pin 9 is normally unswitched from the car and pin 10 is switched via the relay in the car for fridge use. I've just checked my Bailey caravan manual and they don't give a diagram, however they do mention the automatic relay to select the power source. When the car is connected via lead the car power will be used. When the car not connected the battery and or the power supply will be used to power the caravan.

Pin 9 goes via the habitation relay in the caravan. This isolates all the caravan 12volt circuits whilst towing as a safety feature and puts the supply to the caravan battery for charging whilst towing.

Pin 10 goes straight to the fridge, controlled by the car relay.

So when towing I have fridge on and caravan battery charging but only when the engine is running.
When caravan is plugged into car without engine running, all the caravan 12V works from the car battery.
When caravan is not plugged into the car, all the caravan 12V works from the caravan battery.

I think this arrangement came in in 1999 and I think there were changes to the 12S socket at that time as well. My previous van was a 1999 and that worked like this.

I would expect the newer destinies with toilet etc to have this arrangement especially if fitted with the 13pin plug, although if they still put batteries in the gas locker, who knows.
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Re: Leisure Batteries

Post by peridot on Tue 19 Mar 2013, 3:17 pm

Tow Itch wrote: As long as the fridge was wired to pin 6 there shouldn't be that much extra current through pin 4 compared to the previous current through pin 2. The major burnout was always through pin 3 if pin 7 had not been wired to earth. Could the encouragement to wire through pin 2 not just have been because only wiring through pins 6 and 4 sucked and everyone could see this?

I think you're probably right. Using Pins 2 and 4 ensures a greater degree of compatibility with towed units.


Ah Um, Ah Um Ah. This is where I start to get stuck. I think the 1st diagram is poor as it shows nothing of how the three 12v +ve supplies are wired within the self sensing device.
As you're going into the detail of telling me that terminal 2 is wired to terminal 4 I presume you are referring to the 3rd diagram or 2nd wiring diagram.

Yes, I was referring to the photograph and connection diagram for the voltage sensing split-charge relay.

To reiterate. I don't understand the nature of how the relay in the 2nd wiring diagram energises the supply pins.

It's difficult because it doesn't show a good representation of the relay. The only operation that makes sense is that, when energised, the 12V feed to terminal 21 is connected through to terminals 11, 14, and 22, thus energising pins 2, 4, and 6 of the 12S socket.


1) This is beyond me and I'd never heard of it at all. Can you provide a link to this standard?
2) I can see why earting pin 2 on a caravan might result in misery if it's wired to a supply on a split charge relay.
3 I've seen pin 5 described as a spare or the loose term of sensing be it reversing or other. But we are talking of pin 2 wired to "ground" to allow the car to sense this. The issues I can see even if everything was wired to this standard:
a) You are speaking specifically of "Grounding On The Caravan" from pin 2 not a caravan side connection to pin 3 (or 7)How does the car sense being grounded to the caravan there is no return except a variable one of indeterminate resistance across the tow hitch itself? This looks strange to me. It is to pin 3 and was often taken from pin 5 See Bugger Bugger Bugger at the end.

I think it was in the Caravan Club document you've linked to that I read the description of the Pin 2 sensing function (although I came across it on a Volvo owner's website with the club logo and header deleted - naughty). It doesn't look like there are any examples of it being implemented in practice so it's probably safe to ignore it.


Allied question relating to mains charging springing from point 3b) So the 12v (ELV) system must be isolated from the 240v supply?
If so how are the transformers of battery chargers wired, are they isolating transformers or are they wired with a common earth potential? If the latter then the 12v (ELV) system is not isolated. Do we have to take care of the type of charger we use? I'm not pretending even 5% of caravanner's would get this but it's a dotting our i's and crossing t's type point.

Interesting point, although I would expect the output of a charger to be fully isolated.


See you have not ventured to wind or solar charging yet. Perhaps as well.

That's one for the future. The panels (and wind generators) are still expensive and installation on a Dandy is not the most straightforward process. If I needed extra capacity my first thought would be to add a second battery, although that carries a severe weight penalty.

Decided to have a look at 13 pin wiring and saw that while you now have 3 earths that pin 9 has now become similar to pin 4 as in it is permanently live. It's switching between auxiliary functions and fridge being reliant on the battery charging circuit. I still have a belief about the auxiliary functions not being available whist driving I wonder if I'm mixing these up? With this set up if you did not have a battery would you then need to wire the fridge to pin 10? See Bugger Bugger Bugger.

I think Pin 10 is always for the fridge. It is interesting that the battery charging facility is described as permanent live which points to the management of charging being done in the caravan. I don't understand the statement "The fridge circuit must work correctly for switching of the pin 9 supply between these functions to occur". In any event I wired the supply to Pin 9 via the split-chage relay so it is, in effect, ignition fed. Even in the later Riva Destiny there is no control gear in the unit. I don't even think there are any fuses. Shocked


EDIT: Having read navver's last post I think I now understand the link to the fridge circuit. The feed to the fridge also energises the habitation relay which applies the Pin 9 permanent supply to battery charging duties. With the car engine not running the fridge and habitation relay are de-energised and the permanent feed from the towing vehicle can be applied to the caravan's 12v circuits. So the habitation relay is effectively a slave of the split-charge relay in the car.





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Re: Leisure Batteries

Post by peridot on Tue 19 Mar 2013, 3:36 pm

navver wrote:

I think this arrangement came in in 1999 and I think there were changes to the 12S socket at that time as well. My previous van was a 1999 and that worked like this.

I would expect the newer destinies with toilet etc to have this arrangement especially if fitted with the 13pin plug, although if they still put batteries in the gas locker, who knows.

You might reasonably expect so but you would be disappointed Smile

I haven't found evidence of any control or protection on the Dandy 12V wiring.

Having now understood how the habitation relay system works, I think I'll fit one and put my 13-pin socket wiring back to standard with a permanent supply to Pin 9.

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Re: Leisure Batteries

Post by navver on Tue 19 Mar 2013, 5:29 pm

I believe the habitation relay is voltage sensing in it's own right and operates independently of the relay in the car which controls the fridge supply.

The habitation relay over rides all the controls in the caravan such as the master 12V isolate switch. It is there primarily to ensure the 12V circuits in the caravan are isolated whilst being towed for safety reasons in case of an accident. Of course the road lights still work.

I can't believe that if it's there for safety reasons, they would rely upon a relay in the car to do the switching.

Checking the IEE regs, the circuit to charge an auxilliary battery should be separate from a circuit to operate a fridge.

IEE Regs for caravan battery chargers say they must comply with:

IEC 60335-2-29, Household and similar electrical appliances – Safety – Part 2-29: Particular
requirements for battery chargers


Whilst I have access to these sort of things I don not for this one.
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Re: Leisure Batteries

Post by peridot on Tue 19 Mar 2013, 7:01 pm

navver wrote:I believe the habitation relay is voltage sensing in it's own right and operates independently of the relay in the car which controls the fridge supply.

The habitation relay over rides all the controls in the caravan such as the master 12V isolate switch. It is there primarily to ensure the 12V circuits in the caravan are isolated whilst being towed for safety reasons in case of an accident. Of course the road lights still work.


Ahh, okay. I may have been jumping to conclusions in trying to work out the reference to the fridge circuit in the Caravan Club guidance.

I may still wire mine that way for simplicity. I could then wire the two outputs from the voltage sensing relay in the car in parallel and take some of the strain off them as I really don't believe they'll last long switching the fridge and charging circuits Smile


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Re: Leisure Batteries

Post by navver on Tue 19 Mar 2013, 10:16 pm

The fridge & charging circuits should be totally separate.

Fridge controlled by relay in car via pin 9.

Charging or dandy 12V circuits controlled by habitation relay in dandy via pin 10.

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Re: Leisure Batteries

Post by Tow Itch on Tue 19 Mar 2013, 10:50 pm

navver wrote:The fridge & charging circuits should be totally separate.

Fridge controlled by relay in car via pin 9.

Charging or dandy 12V circuits controlled by habitation relay in dandy via pin 10.


Hang on this is the opposite way round Pin 9 is definitely the "habitation" circuit.

The confusion well my initial confusion was that:
The C&CC show this(9) split with the battery with the fridge on pin 10.
PF.Jones show this(9) as power suply (split with fridge?) with the battery on pin 10.

C&CC From Bugger Bugger Bugger link
Pin 9 must be permanently live for both battery charging and interior light etc functions to operate. The fridge circuit must work correctly for switching of the pin 9 supply between these functions to occur.

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Re: Leisure Batteries

Post by Tow Itch on Tue 19 Mar 2013, 11:12 pm

peridot wrote:
navver wrote:I believe the habitation relay is voltage sensing in it's own right and operates independently of the relay in the car which controls the fridge supply.

The habitation relay over rides all the controls in the caravan such as the master 12V isolate switch. It is there primarily to ensure the 12V circuits in the caravan are isolated whilst being towed for safety reasons in case of an accident. Of course the road lights still work.


Ahh, okay. I may have been jumping to conclusions in trying to work out the reference to the fridge circuit in the Caravan Club guidance.

I may still wire mine that way for simplicity. I could then wire the two outputs from the voltage sensing relay in the car in parallel and take some of the strain off them as I really don't believe they'll last long switching the fridge and charging circuits Smile


The comments in my last post would show where peridot gained his belief that the habitation circuit depended on the functioning of the "fridge" (Fridge or battery depending on the diagram followed) on pin 10.

The relay could be "independently" sensing but depend on the circuit through pin 10 if it was a voltage in 10 that activated the switching.
C&CC
The supply to pin 10 should be live only when the vehicle engine is running (see section 3.5.15).

I think we see what was desired though I'm unsure of who perceived what safety value in this switching system navver
I can't believe that if it's there for safety reasons, they would rely upon a relay in the car to do the switching.

I've not wired my Dandy nor am I in the process of so doing but from odd bits that I have seen where I initially thought the wiring had been abused by owners.(On reflection not too sure)I would check out all wiring as per peridot's suggestion.

Wiring included the trully brilliant don't wire the battery and the charger into the 12v system but feed them to a 12S socket on the Dandy that you then placed the 12S plug into to make the internal 12v circuits live. I'd believe anything was possible after that.
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Re: Leisure Batteries

Post by peridot on Tue 19 Mar 2013, 11:25 pm

An engineering colleague of mine had a favourite saying - "The great thing about standards is that there are so many to choose from"

And that's before people start misrepresenting them.

The Caravan Club position seems to be the most consistent across the sources I have looked at so I'm sticking with that (fridge on 10, battery charging on 9).

I actually came across the exact schematic of what I'm planning to do. This purports to show the habitation relay system although it's incomplete as it doesn't cover the supply of the caravan circuits from the car. However I'm never going to want to do that so this is precisely how my system is going to be wired when I complete it at Easter ... I think Twisted Evil

The top circuit is 'engine off', the bottom one is 'engine running'.



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Re: Leisure Batteries

Post by peridot on Tue 19 Mar 2013, 11:36 pm

Tow Itch wrote:
The comments in my last post would show where peridot gained his belief that the habitation circuit depended on the functioning of the "fridge" (Fridge or battery depending on the diagram followed) on pin 10. The relay could be "independently" sensing but depend on the circuit through pin 10 if it was a voltage in 10 that activated the switching.

I've found references to the 'habitation' system using both a relay fed off the fridge supply, or a voltage sensing relay, so both appear to be valid ways of achieving this function.

I think we see what was desired though I'm unsure of who perceived what safety value in this switching system navver

I'm glad it's not just me that's baffled by this one. I'm far more concerned to ensure that the electrical system is safe when I'm asleep in my unit than when I'm towing it. It appears now that due to this requirement the active stabilisation systems that are a significant safety feature on modern caravans are technically 'illegal' as they obviously need to remain powered when towing.

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Re: Leisure Batteries

Post by Tow Itch on Tue 19 Mar 2013, 11:39 pm

I only did "O" Level geometrical and engineering drawing and have never drawn other than the most basic of circuits for "O" Level physics or possibly "A" Level (failed) but prise to the guy for showing one activated relay in one position and the other activated relay the opposite way round.

Make it easy for the numpties that's the way to do it NOT.
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Re: Leisure Batteries

Post by Tow Itch on Tue 19 Mar 2013, 11:53 pm

Some where in the back of my head I believe that the requirement to disable functions other than the fridge and the battery are from a concern about interference with the cars electrical function.

Now if we go to the next level of car wiring and vehicle specific wiring packs the car may adapt it's braking and electronic stability programme if it senses it is being towed. I really don't want to go there until I need to. I think I'd need a lot of guidance.

Where and how is the power for the AL-KO and other active stability devices picked up? Through the domestic supply? As Britain seems to have abandoned it's manufacturing base standards seem (particularly on vehicles) to be from German TUV certification. Would AL-KO have developed a system that they couldn't power?
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Re: Leisure Batteries

Post by jake001 on Wed 20 Mar 2013, 12:10 am

The second diagram is not really required as convention is to show relays in de-energised position i.e. ignition off and what happens when ignition is "on" is then pretty obvious. Smile
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Re: Leisure Batteries

Post by Tow Itch on Wed 20 Mar 2013, 12:19 am

jake001 wrote:The second diagram is not really required as convention is to show relays in de-energised position i.e. ignition off and what happens when ignition is "on" is then pretty obvious. Smile

Jake

Coming in at the end and getting clever. Where were you when we were sweating blood on this and would have appreciated your ability and Knowledge. Or are you saving yourself for an appraisal of the strengths and weaknesses of the varying charging systems on differing batteries? Possibly waiting for input from your colleagues at Boeing for that?

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