12V setup for camper trailer.

[loanrangie]

So now that the weathers improving i need to think about adding power to the camper, i looking for a fairly basic 12V setup for mainly powering a fridge and LED lighting plus the odd charging of phones, laptop etc.
I dont want 240V wiring but do have a 400W inverter for those times when the wife wants to use a hairdryer or even a kettle.
For starters will be using a 100 AH deep cycle with provision for adding a 2nd with re charging via a folding solar panel and via the cars D/B system.

[Homestar]

A 400 watt inverter won't run a hair dryer or kettle. A 2000 watt version barely would, and if you go to something that big, remember they will draw nearly 170 amps at 12 volts when running at full load like they would be if your running a kettle or hair drier. That would flatten your battery in short order if you only have 100AH to play with.

Tell your other half to leave those things at home and stick with the 400 watt unit. You will need a 35 to 40 amp supply for that.

Apart from that a 100AH deep cycle and a 120 watt solar panel will run your fridge, lighting and chargers fine - that's what I have and I never go short on power. :)

[loanrangie]

Hairdryer and kettle aside, what should i be starting with ? Some kind of switch panel with circuit breaker and a couple of fused cigi and USB sockets in 2 locations.

[Doc130]

12v setups depend on what sort of camping and for how long you want to go being self sufficient. These things depict battery sizes, solar panel etc

[Homestar]

Hairdryer and kettle aside, what should i be starting with ? Some kind of switch panel with circuit breaker and a couple of fused cigi and USB sockets in 2 locations.

Yep, that's a good start. As pretty much everything these days charges off a USB outlet, make sure you have plenty so everyone's not fighting over them. 2 in each location at least. If you're not up to making your own panel up, there are some good ones on the market that are as easy as wiring them to your battery. Mount the reg for your solar panel close to the battery - don't leave it on the panel. Have a set of connectors to hook your solar up in an easy to get to location that gives you some flexibility in where you can place your panel - on either side of your trailer. If your trailer has a flat surface on top of it, design it so the solar panel stores there and stays connected to the battery - it will always be fully charged when you head out.

[Homestar]

12v setups depend on what sort of camping and for how long you want to go being self sufficient. These things depict battery sizes, solar panel etc

Very true. As an example I run a 120 watt panel, and a single 100 AH deep cycle battery. I run a 38 litre a Engel fridge and 2 strips of LED lights mainly. A small 12 volt pressure pump for water and a big floodlight (27 watt LED) which I use when setting up in the dark, or if there is a need for lots of light.

I can go away almost indefinitely with this setup. Even without the solar panel hooked up I can go 3 days just off the battery. My limiting factor is my fuel bill, not the amount of power I have.;)

[Doc130]

Bicicat, to be honest I doubt you could camp indefinatley with that setup. Fair enough saying you can go three days without charge but if we really want to get all technical about 12v, without doing the calculations I would say you would have the battery well under 50% charge after three days which is not exactly what deep cycle batteries like. To give the ultimate setup for battery life you never want to let your deep cycle battery go below 50% charge at any point, ever! However, not many people think of this when designing their 12v system. Not knocking your setup at all coz it would work great, just thought it is worth mentioning. Personally when I think of indefinatley, you want to be able to go a week without sun or any sort of charge. This should cover almost all situations, if it was raining for that long I'm sure that you would probably pack it up and move on.

[Homestar]

Bicicat, to be honest I doubt you could camp indefinatley with that setup. Fair enough saying you can go three days without charge but if we really want to get all technical about 12v, without doing the calculations I would say you would have the battery well under 50% charge after three days which is not exactly what deep cycle batteries like. To give the ultimate setup for battery life you never want to let your deep cycle battery go below 50% charge at any point, ever! However, not many people think of this when designing their 12v system. Not knocking your setup at all coz it would work great, just thought it is worth mentioning. Personally when I think of indefinatley, you want to be able to go a week without sun or any sort of charge. This should cover almost all situations, if it was raining for that long I'm sure that you would probably pack it up and move on.

Been out in it for weeks straight - never had an issue. Stayed in one spot many nights in a row - no issue. You are right about running it 3 days straight without charging it - it drags the battery down, and it isn't great for it - I only did it that time because I forgot my solar panel...:angel: That won't happen again as it permanently mounted now - not ideal, but still works fine.

Oh, and when I'm home from trips, I sometimes forget to plug the fridge back into 240 volts and just leave it on this system and I've had it go over a month and still had a couple of beers in there at zero degrees when I remembered to plug it in and the battery sitting on 12.7 volts - that was just recently coming out of a Victorian Winter. That's pretty much indefinitely in my book. :)

Oh, and I'm a Sparky by trade who specialises in DC control systems so I sort of understand what I'm up against. ;)

[Doc130]

Maybe in a Victorian winter, it must be close to zero anyway, but anywhere where the ambient temp is even above 25 degrees I don't believe you could run a engel fridge especially, for one month and on a 100ah battery and still have 12.7 volts. Engels aren't as good on current draw as people think. I've got a shunt setup which doesn't lie. I've run A few mates Engels of varying sizes for a test and my nation luna. Luna wins hands down!

[drivesafe]

To give the ultimate setup for battery life you never want to let your deep cycle battery go below 50% charge at any point, ever!

First off, hi Doc and not taking a deep cycle battery below 50% is a myth.

All deep cycle batteries have always been able to be discharged down to 30% but all modern deep cycle batteries can be safely discharged down to 20%.



Hi Loanrangie, can you tell us more about your set up and intended usage?

What size solar panel do you plan to get or already have?

What sort of set up do you have in your tow vehicle?

Are you planning to set up in one spot and stay there or to move regularly from one spot to another or set up in one spot but do lots of day driving?

All this and any other info you have will help you to set up to meet your specific needs.

[Homestar]

Maybe in a Victorian winter, it must be close to zero anyway, but anywhere where the ambient temp is even above 25 degrees I don't believe you could run a engel fridge especially, for one month and on a 100ah battery and still have 12.7 volts. Engels aren't as good on current draw as people think. I've got a shunt setup which doesn't lie. I've run A few mates Engels of varying sizes for a test and my nation luna. Luna wins hands down!

Whatever dude. I don't like being called a lier - you obviously don't believe me, so that's your issue. I know what I've got out of this system and so do many others here I've been out with. I'll stick to trying to help the OP with his question from now on and I'll not respond to your rantings again.

[TerryO]

First off, hi Doc and not taking a deep cycle battery below 50% is a myth.

All deep cycle batteries have always been able to be discharged down to 30% but all modern deep cycle batteries can be safely discharged down to 20%.


I would be interested to see any documented proof of this from battery makers etc. that their deep cycle battery's can be run down to even 30% of charge on a regular basis and it won't dramatically shorten their life span.

Having many mates who run their fridges off of AGM battery's in their campers one thing I have noticed is while most have some sort of solar charging system fitted nearly none of them have a regulator that tells them what charge their battery has in it and or at what rate the power is being discharged or charged for that matter.

I understand that the only true way of measuring a battery's actual charge is to wait several hours after charging and with no draw down happening but still having some sort of measuring system is better than nothing because it still gives you an indication.

We have a ProStar 30 regulator fitted in the Caravan and it shows you everything you need to know including charge rate, discharge rate and what volts you have in your battery. If you have a good solar system it will also show you when your battery's are fully charged and the system is floating. I have attached a YouTube video of one being used, it is being used with 24 volt but forget that and much of what old mate is saying however it shows basically how it works and what you can see. Below is a chart that if used in conjunction with a regulator like the ProStar 30 that you can see how far down you are running your battery's. The regulator goes into float at 13.4 volts from memory, which even after a big night of using heaps of power it usually is in float by 9:00amish the next morning in late spring, summer and or most of autumn. If you don't have a reliable system that can show you this info then how would you ever know if your system is adequate or not?

https://m.youtube.com/watch?v=ApcU-Ne3K6k

[Homestar]

Good points Terry. I just use a cheap ebay voltmeter to monitor the voltage and my solar controller shows when it is actively charging or float charging the battery. I know the current draw of my appiances and what sort of voltages I can expect in the morning before the solar kicks in for the day.

Once you know how your system performs, you become less fixated on amps in and amps out but yes, you should have something in place that allows you to understand what's going on.

[TerryO]

I can't help myself, I wake up in the morning and straight away look over to see if the green light is flashing or not to indicate its on float.

I have worked out what every appliance and light in the van uses power wise after turning them on one at a time and watching the regulator go through its cycles.

Even though we have two 100amp AGM's when the van had normal bulbs fitted you could almost watch the battery's drain away before your eyes it happened that quick if they were all on. Now with LED's fitted even with every light on inside and out it only draws about 2.5 amps.

[jx2mad]

So Bacicat, are you saying that if your fold-up panels have a regulator fitted it should be moved to near the battery? It makes sense because of the voltage drop on the leads. Jim

[TerryO]

The regulator should be fitted as close to the battery's as possible.

[Homestar]

So Bacicat, are you saying that if your fold-up panels have a regulator fitted it should be moved to near the battery? It makes sense because of the voltage drop on the leads. Jim

Yes - for the reason you said. They all come fitted with the controller on the panel, but you will be able to run a longer lead with less voltage drop if you mount the controller near the battery. The unregulated output of the panel is quite a few volts higher and every little bit helps. It's also easier to see what the reg is doing at any given time if you place it somewhere easy to see rather than having to tilt the solar panel up if you want to take a peak. :)

[Homestar]

I can't help myself, I wake up in the morning and straight away look over to see if the green light is flashing or not to indicate its on float.

I have worked out what every appliance and light in the van uses power wise after turning them on one at a time and watching the regulator go through its cycles.

Even though we have two 100amp AGM's when the van had normal bulbs fitted you could almost watch the battery's drain away before your eyes it happened that quick if they were all on. Now with LED's fitted even with every light on inside and out it only draws about 2.5 amps.

Ahh - LED lighting - hasn't that transformed camping. :)

My 2 strips under my awning draw just over 2 amps and the ones inside a bit less. I don't feel guilty leaving them on for ages. I used to have some small incandescent globes years ago - just indicator globes, but at nearly 2 amps each, you had to be content to work with much less light.

[drivesafe]

Hi Terry and you WILL shorten the life span of any deep cycle battery if you take it down to 20% on a regular basis.

To get the maximum life span out of a battery, or more accurately, to get the maximum energy through a battery over it’s life span, you should not discharge it lower than 80% to 65% depending on the make and type of deep cycle battery.

As I posted, this “50%” is nothing more than a mythical number plucked out of thin air and has nothing to do with life span of batteries.

If you were living the type of life style where you depended on your batteries 24/7, then as above, to get the maximum use from your batteries, 65% to 80% is as low as you should allow your batteries to get.

This is an RV thread and a question relating to RV use. As such, someone trying to work out what sort of use, based on expected life span, can factor in safely discharging the battery down to 20% SoC ( 11.58v ) and getting a good life span from a battery.

If you factor in cycle rates vs discharge level vs “Expected” life span of a battery, you get the real world use of a battery.

If you look at page 8 of the Fullriver manual, the cycle rate at 50% ( 12.06V ) discharge level is around 1250, but as pointed out, by cycling the battery down to 20% SoC ( 11.58v ) you will only get a little over 750 discharge cycles.

Now to the “Real World“ use of a battery.

If you use this battery every day and discharge it down to 20% every day, then you would be lucky to get 2 years use from the battery.

If you used it every weekend, and every weekend you discharged down to 20%, your “expected” life span is now 14 years.

If you only use it once a month, your are now looking at an “expected” life span of of over 50 years. NOT LIKELY!

If you get 6 to 8 years out of most deep cycle batteries, you are doing well, so the governing factor for how low you can discharge a battery and still expect a decent life span is how often you actually plan to use the battery, not some mythical 50% discharge depth.

Here are some links to where the battery manufacturers state discharging their battery to 20% SoC is safe.

SPECIAL NOTE, while these documents are a good guideline, they are “BATTERY SPECIFIC” and you need to get the specific data for your specific brand and model of battery, as every battery is different.

Deep Cycle Battery, Mazda & Truck Battery (http://www.supercharge.com.au/deep-cycle-battery-care)

Battery Maintenance | Trojan Battery Company (http://www.trojanbattery.com/tech-support/battery-maintenance/)

http://www.fullriverdcbattery.com/media/pdf/technical/installation_manual.pdf

[loanrangie]

Thanks Gav, folding panel and a 100ah battery is what i want to start with and then make additions /progressions as required.

Hi Tim, we have simple power requirements at the moment being mainly fridge and led lighting.
I dont have a solar panel yet but will be buying one shortly along with fridge and deep cycle battery, power from vehicle is further down the list with an upgrade from the old pirahna isolator that was transferred from previous vehicle. Water tank and pump is on the list for additions.
We mainly do short base trips but i dont want to be limited to this if we decided to go longer.

[Doc130]

Terry, good to see someone on the same page. As far as 50% rule! that's just a good guide! ultimately you want to keep a deep cycle battery close to 100% all the time but in real life it's hard. I can guarantee that discharging battery's down to 20 -30% regularly will dramatically reduce battery life. Now if you don't care about buying batteries every year or two than that's fine! However, myself I have lifeline AGM batteries which are not cheap and do not want to be replacing them any time soon, this is why I have a shunt and bmi which tells exactly how many amps are either charging or discharging. This is handy for getting max amps out of your solar panel by adjusting the angle and watching the bmi.

[drivesafe]

I can guarantee that discharging battery's down to 20 -30% regularly will dramatically reduce battery life. Now if you don't care about buying batteries every year or two than that's fine!

As long as a battery is properly maintained and not abused in other ways, this would only be the case if the battery was cycled down to 20% SoC EVERY DAY.

But for normal RV use, the battery will die of old age way before this sort of discharge had any effect on the battery.

[drivesafe]

I dont have a solar panel yet but will be buying one shortly

Hi again loanrangie, and setting up your solar first has a number of advantages.

When your trailer is not in use, if you have your solar set up so it can still be used at home, you can let your solar maintain your batteries in your trailer, removing the need to have to periodically connect a battery charger to them.

Also, as other have posted, try to fit the regulator as close to the batteries as possible but also make sure you connect the solar to the regulator and then the regulator to the batteries with decent size cabling.

Unlike when charging from an alternator, where you have the ability to supply a current over a given length of cable and any lose caused by voltage drop is made up for by the alternator being able to produce more current.

With any solar setup, there is a defined maximum current output of a solar panel, and while PWM and MPPT regulators can increase the voltage at the panel, if there is a voltage drop of any significance, anywhere in the set up, the current lose caused by voltage drop, can NOT be made up, and this will mean a current reduction at the batteries.

So use over sized cabling for you solar set up to keep voltage drop to a minimum.

One more point, the chart Terry posted is an OPEN CIRCUIT voltage chart and not relevant while you are using any form of lead acid battery.

OPEN CIRCUIT voltage charts can also be battery specific and they are only reliable if you have other info to factor in, such as others have posted above, like amps ( watts ) in and out.

If you just take a voltage reading when using a OPEN CIRCUIT voltage chart, the batteries have to be sitting in an unused state, No-Load/No Charge, for at least 6 hours but 24 hours is needed to get an accurate indication of the battery’s SoC.

And again, without other factors being known, using an OPEN CIRCUIT voltage reading has other potential drawbacks, like you can get an OPEN CIRCUIT voltage reading that indicates the battery is fully charged, but apply even a very small load and the battery can go flat in minutes.

The chart below is for getting a fairly accurate indication of the SoC of batteries while they are in use, with a small load of no more than 5% of the total current capacity of the batteries being tested.

For example, if you have 100Ah of battery capacity, the load needs to be no greater than 5 amps.

https://www.aulro.com/afvb/images/imported/2016/06/640.jpg

[TerryO]

Sorry not to sure after comparing the two charts how this works Drivesafe?

You say that chart I put up is not relevant even though if you compare it with the one you put up it is basically the same.

I invite you to go back and compare the two charts and also read all of what I said.

[drivesafe]

Hi Terry and sorry mate, you are spot on the money, the two charts are the same.

I was on another forum, covering the same subject, just before I posted up here.

Brain does not working too well at that time of the day.

Cheers, Tim

[kelvo]

When your trailer is not in use, if you have your solar set up so it can still be used at home, you can let your solar maintain your batteries in your trailer, removing the need to have to periodically connect a battery charger to them.

Hi Tim,

If solar is not being used to maintain the battery, at which point should you connect a charger to it? Is it bad to leave a charger (3 stage for instance) permanently connected when at home, or are you just wasting electricity?

Thanks,
Kelvin

[loanrangie]

Thanks Tim, looking at panels right now. One i'm looking at (120W folding ) comes with regulator and wiring for a remote reg setup and shows the ideal setup of reg close to batteries which none of the other sellers do, this makes me more inclined to go that way.
And if i wanted/needed to replace the reg it would be a simple task, using the panel for battery maintenance sounds like a good idea too.

[TerryO]

Out of interest LoanRangie what price is the panel and reg?

Many of these solar kits you see on ebay etc might seem well priced at first glance but actually aren't very good value when compared the prices you often can get good quality panels and regulators for now.

If you have a good quality regulator like a ProStar 30 fitted next to the battery in the camper then not only can you see what your charge input is and what drain you are taking out of the battery but you can see how much charge you have left in the battery. plus you can add more panels later without a worry because the regulator is up to it and if you have good quality cabling then you can have the panels a little further away to follow the sun if you don't have a choice because where your parked.

[loanrangie]

Looking at sub $200 for a 120W folding panel, from the members here with similar panels i dont think i need to spend any more on the panel but possibly the reg at a later date if i need to.
If i was only buying the panel on its own i might spend more but in the next week i'll be a buying fridge, 2 x batteries and the panel plus associated wiring, sockets and cable etc to wire the camper.

[Homestar]

I've got a relatively cheap panel and it works fine - I can get about 8.2 amps out of it in full sun, but that drops quickly when any shade is present. I believe the more expensive panels cope better and output more power in part shade.

Ideally I would mount mine so it runs all the time so keeps the batteries fully charged at all times while not in use (mine does this now) but is removable from its mounts so it can be moved around more easily at a camp site (which mine can't be)

[landy]

In the OP Loanrangie asked about fitting plugs and power outlets. Does anyone have a preferred spot to place theirs? I would be interested to see other set ups for both 12v and 240v to gain some ideas. I'm following with intrest.
I made up a bed head for mine and fitted it with 2x LED lights and 2x double USB sockets to charge the iPhone's and iPads. It plugs into one of the cig sockets at the side of the bed. I find this works well. I also have a double socket at the rear for the kitchen light and fridge.

Cheers

Nino.

Edit. I have no idea why the photo is upside down. It's fine in the album.

[loanrangie]

Good idea on the bedhead Nino, i'm thinking a pair of cigi /usb sockets under side of the trailer just below the bed.
This side is open to the tent so easy to get to, also another pair at the kitchen end for fridge and any other 12V appliances that we might use.

[drivesafe]

Hi loanrangie and hope you don’t mind if I highjack your thread.

While in keeping with the last few posts, has anyone come across a decent plug and socket that works for RV use.

Cigarette Lighter type power sockets are renown for the plugs to fall out and in too many cases, for the plug and socket to melt.

Merit type plugs resolve the problem of the plugs falling out but they are still susceptible to melting.

I use Anderson Power poles and while they safely handle loads up to 30 amps, and are VERY small, they are only useful when used in an In-Line setup.

They do come with a number of panel type mounts but while you can walk on them and not break them, in the panel mounts, if you bump them from the side, they break quite easily.

So again, has anyone come across decent plugs and socket, that look good as well, for 12v use?

[bee utey]

Hi loanrangie and hope you don’t mind if I highjack your thread.

While in keeping with the last few posts, has anyone come across a decent plug and socket that works for RV use.

Cigarette Lighter type power sockets are renown for the plugs to fall out and in too many cases, for the plug and socket to melt.

Merit type plugs resolve the problem of the plugs falling out but they are still susceptible to melting.

I use Anderson Power poles and while they safely handle loads up to 30 amps, and are VERY small, they are only useful when used in an In-Line setup.

They do come with a number of panel type mounts but while you can walk on them and not break them, in the panel mounts, if you bump them from the side, they break quite easily.

So again, has anyone come across decent plugs and socket, that look good as well, for 12v use?

Hi drivesafe,

I have been using Merit plugs for 25 years and could offer some observations.

The sockets are usually aluminium and must be capped all the time they aren't used. They corrode fairly easily if unprotected in a damp environment. On that note I've seen brass merit sockets on ebay recently that may help.

10X Merit Hella Socket Flush Panel Mount 12V 12 Volt Accessory Power 12V Fridge | eBay (http://www.ebay.com.au/itm/130847423106'ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649)

The original Hella design has all round contacts for the earth side and are less likely to melt. One of my old Engel cables has an original one and it's lasted very well on a 6A motor load. Similar looking to this type:

5X Male Hella Merrit Plug Great FOR Camper Trailer 4x4 4WD Thumper AGM Battery | eBay (http://www.ebay.com.au/itm/5x-Male-Hella-Merrit-plug-great-for-Camper-Trailer-4X4-4WD-THUMPER-AGM-Battery-/301348493980?pt=AU_Electronics_Accessories_Power_B oards_Cables&hash=item4629c51a9c)

Having said that I don't have much of a problem with the single point Narva brand plugs so long as they go into clean sockets. On the other hand the multi fit cig/merit plugs I've sen have been utter crap.

[Hoges]

Hi loanrangie and hope you don’t mind if I highjack your thread.

While in keeping with the last few posts, has anyone come across a decent plug and socket that works for RV use.

Cigarette Lighter type power sockets are renown for the plugs to fall out and in too many cases, for the plug and socket to melt.

Merit type plugs resolve the problem of the plugs falling out but they are still susceptible to melting.

I use Anderson Power poles and while they safely handle loads up to 30 amps, and are VERY small, they are only useful when used in an In-Line setup.

They do come with a number of panel type mounts but while you can walk on them and not break them, in the panel mounts, if you bump them from the side, they break quite easily.

So again, has anyone come across decent plugs and socket, that look good as well, for 12v use?

For years I have been using 6.5mm (mono) audio plugs from Jaycar. Various shaft lengths and even come in right angle versions. see p197 of their downloadable pdf catalogue. I originally used one in desperation when I converted a cheap 12V cordless drill to run off a car battery. Cable was same gauge as used to provide sufficient amps for caravan electric brakes. Drill was used in this configuration to screw 800 stainless steel screws (10g 67mm) into a hard wood deck ...I add this momentous detail :eek: by way of saying that the plug never got warm and carried the current easily...
Advantages: they are firmly held in place, are generally robust, will take 15 amps for extended periods..., they are quite cheap compared to Anderson plug prices (for genuine Andersons that is!)
Disadvantages: the plugs protrude somewhat, so a right-angled version may be a lot less obtrusive

[Owl]

..... While in keeping with the last few posts, has anyone come across a decent plug and socket that works for RV use......




How much do you want to pay?

Hella Mining :: MagCode Power Systems (http://www.hellamining.com/index.php/accessories1/mag-code/)

[loanrangie]

I only plan on using cigi sockets for those items that already have a power lead with cigi plug already and not about to cut them up, i agree that they arent ideal for certain equipment but for my purpose they will be fine.