Camper Battery

[dickyjoe]

Hi

I have a camper trailer that had a marine lead acid battery in it with a simple low/high cut in relay to charge the battery from the vehicle through a 50amp cable.

The battery has died and I am in the market for a new one.

I'm thinking of a absorbed glass mat battery and installing a multistage DC/DC charger to properly charge the battery.

I'd also like to be able to charge the battery via a solar panel through the DC/DC charger.

My question is what are some good makes of battery and multistage DC/DC chargers.

Richard

[Tank]

I have that exact same setup on my CT, a fold out solar panel, a C-Tek DC to DC charger that takes it's power either from the tow vehicle or the solar panel and 2 Optima AGM yellow top batteries (deep cycle), works extremely well, Regards Frank.

[Pedro_The_Swift]

One of my 3 is one of these--
https://www.aulro.com/afvb/images/imported/2016/11/573.jpg

My only comment on DC chargers is,
I run 500W of solar.

[DiscoMick]

C Tek, Matson, Projecta, Redarc etc

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[dickyjoe]

Hi Thanks for the info.

I've started looking at C-Tek chargers.

There is this one which I think would be ok :-
D250S DUAL (http://www.ctek.com/au/en/chargers/D250S%20DUAL)

or this one :-
SMARTPASS (http://www.ctek.com/au/en/chargers/SMARTPASS)

I'm not sure I understand the difference between the two.

Once I've worked this out I'll look for a battery.

[Slunnie]

For deep cycle, my choice is Lifeline. You will pay for them, but they have capacity for their size, same technology as Optima (except flat plate) and they are very robust and long lasting.

For the large Optima size (75ah), the lifeline will give you 100ah. Same footprint but 70mm taller will give you 150ah.

[DiscoMick]

Most DC-DC chargers operate at 20A to 30A. Above that may exceed the maximum rate at which a particular battery can be charged.
Note that there are solar and non-solar versions of most chargers so check.
Whether you need a DC-DC or not may depend on the location of the battery. If you are using solar to charge the DC'DC may limit the solar input to 10A anyway, just like a solar regulator, so a 20-30A DC-DC may not be any advantage and you could just buy a 10A regulator for the solar for $20-30. So check the DC-DC's specs to see if it boosts the solar by more than 10A. While the current from the vehicle is steady the current from the solar can vary greatly.
However, where a DC-DC is useful is if you want to boost the current coming down the plug from the vehicle to compensate for voltage drop from front to rear of the vehicle and speed up charging of the trailer battery while the attached vehicle engine is running.
Putting a DC-DC in the actual vehicle may be pointless as your alternator should put out at least 80A anyway, much more than the DC-DC can operate at.
So in our case I have a Matson DC-DC in the camper to bump up the current from the vehicle to 20A, but my solar goes directly to the battery. The solar probably only makes a max of about 4A anyway.
I'm no electrician so others may give better advice. Hope that helps.


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[dickyjoe]

Hi all,

I'm looking to be able to properly charge the battery as a multistage home battery charger would, hence the idea of a 12/12v charger.

[Homestar]

One of my 3 is one of these--
https://www.aulro.com/afvb/images/imported/2016/11/573.jpg



Same as I use, but I got only 2 of them - I've never been able to bring them down very far from fully charged, even when I have left a pedestal fan going all night when it's hot. :)

I think for what I use, I could get away with just one and save myself the extra weight, but I probably won't.

DC - DC chargers are a controversial topic, my take on them is save your money to buy something else. They add weight and slow down the charging of the battery. As Pedro mentioned, solar is all that needs to be said. A solar system will bring your batteries up as far as any DC - DC device and will automatically maintain the batteries as well and keep them trickle charged just like a multi stage charger - all done.

When you're driving along your cars alternator can charge your house batteries much faster if you connect it directly and not put it through a DC DC device.

[Tank]

Hi Thanks for the info.

I've started looking at C-Tek chargers.

There is this one which I think would be ok :-
D250S DUAL (http://www.ctek.com/au/en/chargers/D250S%20DUAL)

or this one :-
SMARTPASS (http://www.ctek.com/au/en/chargers/SMARTPASS)

I'm not sure I understand the difference between the two.

Once I've worked this out I'll look for a battery.
That's the C-Tek charger that I have, regards Frank.

[dickyjoe]

That's the C-Tek charger that I have, regards Frank.

The D250S or the SmartPass

[Homestar]

Hi Thanks for the info.

I've started looking at C-Tek chargers.

There is this one which I think would be ok :-
D250S DUAL (http://www.ctek.com/au/en/chargers/D250S%20DUAL)

or this one :-
SMARTPASS (http://www.ctek.com/au/en/chargers/SMARTPASS)

I'm not sure I understand the difference between the two.

Once I've worked this out I'll look for a battery.

While I don't want to sound nasty, they're both a waste of money IMO. Batteries will draw current as needed, they don't need anything like this to pull a charge for something. Too many people get sucked into thinking they need stuff like this when they simply don't.

Connect your solar to the batteries, your cars alternator to the batteries when you plug the camper/caravan in, and you're done.

Doesn't matter what batteries, where they are, what car - it will work best wothout all the electronic guff the snake oil salesmen will try and convince you you need,

If you understand electricity and battery chemistry, you'll realise this simply isn't needed.

Just my 2 cents, I've been running dual, triple and quad battery setups for years without any issue, all different types of cars and alternators. I've never gone short of power or had any issues, my batteries last years.

Just sayin...

[rangieman]

While I don't want to sound nasty, they're both a waste of money IMO. Batteries will draw current as needed, they don't need anything like this to pull a charge for something. Too many people get sucked into thinking they need stuff like this when they simply don't.

Connect your solar to the batteries, your cars alternator to the batteries when you plug the camper/caravan in, and you're done.

Doesn't matter what batteries, where they are, what car - it will work best wothout all the electronic guff the snake oil salesmen will try and convince you you need,

If you understand electricity and battery chemistry, you'll realise this simply isn't needed.

Just my 2 cents, I've been running dual, triple and quad battery setups for years without any issue, all different types of cars and alternators. I've never gone short of power or had any issues, my batteries last years.

Just sayin...

Gav is right save your money buy a decent AGM connect a min 120w solar panel for when stopped and charge off the car when traveling .
This is all i do and have done on my camper since 2011 . When my camper has sat for a month or 2 i put my projector smart charger on for a day and night;)

[Tank]

The D250S or the SmartPass
The D250S , Regards Frank.

[Tombie]

Dc-Dc chargers still require fat cable to be effective...

So what vehicle are you using as the primary tug/power source?

I would be suggesting:

No Dc-Dc charger; fit decent cable to the rear.
Solar regulator and panel(s)
Decent battery as recommend above..
Then fit a 240v charger on board for those stays with power or maintenance.

[Trout]

I have the Ctek 250s in my camper trailer. Not a lot of use so far but it works just fine. Ctek stuff is generally very good imho. I also use lifeline batteries. They are brilliant. I grabbed an old one off my yacht for the camper. It is past it's pirime as it sat dead flat for a long time and it is probably well over 5 years old. It still works fine for the camper.

I only had a quick look at the smartpass but it seems the only other feature is a low voltage cutoff for non critical loads so that you have some reserve battery power for critical stuff. Unlikey to be of any use in a camper.

Regarding the various comments about the need for a dc/dc charger. There are many different solutions for charging batteries all with pros and cons. To say that dc/dc chargers are unnecessary is true but also a simplification.

I don't have solar panels. I have minimal battery capacity for my usage. Did not want to have really heavy wiring runs and wanted a no fuss option that would ensure my battery was properly charged. I had some things in place already so a dc/dc charger suited my situation well for minimal cost.

Using a good size solar panel and a smart regulator with a simple heavy gauge charging circuit from the cars second battery for some bulk charging would be a good option also. Really just depends on your usage and what gear you have allready.

[dickyjoe]

Where is the cheapest spot to buy a full river battery?

[Homestar]

Where is the cheapest spot to buy a full river battery?

Not sure what they retail for but I can get you a price from my mate who stocks them so you can compare if you want.

I got mine through him, they are brilliant batteries, but I didn't pay for them, he owed me a favour, so no idea what they should go for. ;)

[drivesafe]

Hi Richard and while I hate getting involved in these threads, but people are continually misunderstanding the real operating potential or more correctly put, the LACK of any genuine potential of DC/DC devices.

For a starter, you posted to QUOTE " I'm looking to be able to properly charge the battery as a multistage home battery charger would ".

The problem is that while marketed as being able to charge like a multi stage 240vac battery charger, DC/DC device CAN NOT charge like a battery charge for one very simple reason. You will not drive long enough.

The average drive time for anyone towing a camper trailer is 2.5 to 5 hours.

If you have been camping and you have a 100Ah battery that you have discharged down to 20% SoC, using that DC/DC device, you will need at least 5 hours driving time just to get your battery charged to around 95+%, and you will still not get any advantage from the multi stage end of charge, these devices offer.

Whereas, just charging direct from your alternator, and using decent cabling ( 6B&S = 13.5mm2 ), your alternator will have the same battery at around 95+ in about 3 to 3.5 hours of driving.

If after a trip or two, you decide you need more battery capacity, then that 20 amp DC/DC device will now need around 9 hours of constant driving, while your alternator will replace the same amount of used battery capacity in around 4 to 5 hours.

As has already been pointed out by others in this thread, DC/DC devices are a gross wasted of money when used in any Land Rover, including the new RR and RRS with Stop/Start operation.

A far smarter way to charge your battery faster, is to add another battery.

As strange as this may seem, but by using two batteries of the same size as the one you have now, you will recharge them in less than 2/3 of the time it takes your alternator to replace the same amount of battery capacity used in a one battery setup.

[DiscoMick]

After investigating I decided against fitting a DC-DC charger in the Defender.

I'm no expert, but as I understand it, DC-DC chargers usually limit the flow to 20-30 amps, but LR alternators usually make at least 80amps, so to install a DC-DC would actually reduce the current reaching the batteries. For example our starting and second batteries are linked with fat cables and 60 amp fuses. Why would I want to limit the current flow to 20-30 amps?

A DC-DC is useful if the current flow is less than 20 amps. I have one in the camper to compensate for voltage drop from the engine bay down the vehicle and through the trailer plug to the camper. That's a different situation to in the vehicle with the alternator pumping directly into the batteries.

A 240 volt multi-stage charger is for when a battery is to be left for longer periods to slowly push the final 5% of charge.

So its important to think about the situation. Hope that helps.




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[drivesafe]

A DC-DC is useful if the current flow is less than 20 amps. I have one in the camper to compensate for voltage drop from the engine bay down the vehicle and through the trailer plug to the camper. That's a different situation to in the vehicle with the alternator pumping directly into the batteries.

Hi Mick and again this is a misunderstanding of how batteries charge.

By simply using decent cabling between your cranking battery and your camper trailers house battery, you will still charge the battery in your camper trailer faster, direct from your alternator.

Contrary to most people's thinking, if you have a decent cabling setup, all in good condition, then yes you may still have voltage drop at the house battery.

But you need to understand what is causing the voltage drop in the first place.

If you have say 10m of twin 6B&S cabling running to your camper battery, and you have a low 120Ah battery in your camper, it might be causing over a 1.0v voltage drop between your cranking battery and your house battery.

Now this may sound pretty bad, but it's only half the story.

If your house battery is low, it could be drawing 35+ amps and a 35 amp current draw over 10m of 6B&S twin is going to cause a 1.0v voltage drop.

In this setup, the voltage drop is irrelevant because the battery is still drawing ( being charged with ) 35 amps.

So as above, knowing the voltage is only half the story.

Further more, if you were to connect your 20 amp DC/DC device to the same low battery, where the voltage at the battery from your alternator ( at 14.4v ) is going to be around 13.4v, your 20 amp DC/DC device will only be delivering 20 amps at less than 13.0v. Most people o not know this!

In both cases, the voltage at the house battery terminals will rise as the battery charges, but as your alternator is delivering a higher current right from the start, your battery will reach a fully state of charge far sooner than what your DC/DC device can do.

NOTE, this all relates to moderate to high house battery capacity usage.

If you are just topping a battery up then yes, a DC/DC device will do it sooner, but it's not hours sooner, it is more likely to be no more than 20 minutes sooner.

So if it takes your DC/DC device 60 minutes of driving, to top up your battery and your alternator takes 90 minutes but you are going to be driving for 2.5 hours, where is the advantage????????????????

Sorry folks, in the vast majority of setups, these devices are a poor second rate form of charging when compered to what decent cabling and your alternator can do.

[DiscoMick]

Yes, thanks for that and I certainly agree it is best to have a nice thick wire running directly to the trailer plug on the vehicle. However we didn't have that in our D1, when I put the DC-DC in the camper.
Instead the trailer plug was just picking up power from the rear of the vehicle. So I think the camper battery benefitted from a DC-DC in the camper.
Its a different situation with our current Defender which has a good connection to the trailer plug.
Again, thanks for your informative posts - I keep learning from them.


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[dickyjoe]

So I'm looking into batteries. Where is the best place to buy lifeline batteries

[Trout]

So I'm looking into batteries. Where is the best place to buy lifeline batteries

Whitworths Marine sells them possibly not the cheapest.

[Trout]

Interesting discussion about the merits or otherwise of dc to dc chargers. Have a look at this Dc-dc charging (http://caravanandmotorhomebooks.com/dc-dc-charging-2/) and what it's says and in particular what it says about the Ctek smartpass. I misunderstood what it did from my quick look at the web page.

[DiscoMick]

Interesting article.
In my case it appears to confirm I wouldn't gain much from fitting a DC-DC to the Defender, but I am benefitting from having one in the camper.


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[drivesafe]

Hi Trout, mate be very careful of anything Collyn Rivers posts up. He is NOT an authority on anything to do with automotive electrics, and is a devout liar.

For an example, he states that "A vehicle's starter motor is designed to work with a 70%-80% charged starter battery"

The battery size used in any vehicle is based on the CCA of the battery. The CCA of a battery is based on that battery being able to supply that CCA at 40% of the battery's total capacity and to do so at a temperature of 0F ( 32C ).

So he he has no idea what he is talking about and you can prove this yourself. If you ever end up with a cranking battery that has, for what ever reason, been discharged down to 40% SoC or 11.9v, you will have no problem starting your motor, because that is what the vehicle manufacturers has set their minimum battery requirements for any given vehicle, but this still leaves a good safety margin.

In reality, you can start a motor on any modern vehicle with a battery as low 11.58v or 20% SoC.

This sort of voltage level has absolutely nothing to do with how batteries are charge in an automotive setup and Collyn is doing nothing more than trying to muddy the waters to try to confuse people into thinking the alternators can not full charge any battery connected to it.

Collin is not interested in the truth, because he has his own hidden agenda, and one he has been caught at many times, as he is out to promote DC/DC devices for one of the vendors.

Now for some facts. There are now more than 4,000 D3, D4 and RRS vehicles fitted with my systems world wide, and the vast majority of those towing camper trailers and caravan, DO NOT have DC/DC devices fitted in their trailer or caravan, yet they have no problems charging and maintaining any number of batteries in their trailers and vans.

This is an E-mail I received a while back and demonstrates the need to get RELIABLE info before equipping a vehicle with a DBS that actually works and not rely on what so called experts in this field claim.

These guys fitted their own DBS and had no problems yet the fifth guy got his DBS "professionally" installed, and look at the results.

Note, the D2 has a constant voltage alternator, the D3 has a variable operating voltages, and the D4s have Regenerative Braking Voltage operation.

This covers just about every type of alternator operation.

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Hi Tim

Sorry for the long email - in the second half of the email my mate with a 200 series wants to know if you can help him

It seems like only yesterday that we installed your dual battery kits in 4 vehicles (D3, 2 x D4, D2) ready for a big trip. We've been back a while so I just wanted to give you an update on how the battery kits went.

In short, they were brilliant. We installed all 4 kits you sent us in one day. Aside from the fiddly process of removing trim pieces and working in the tight confines of a Land Rover engine bay the installation was straightforward with your instructions.#
Throughout the trip the kits never missed a beat - and others on the trip had lots of electrical issues.

On a few occasions the battery guard did it's job cutting out the fridges, but this was usually when we were camped in one spot for a few day (very little or no driving) in very hot weather (making the fridges run almost non-stop). It took surprisingly little driving to provide a good bulk charge back into the batteries.

We travelled the Tanami Track, Gibb River Rd, Kalumburu Rd, Mitchell Falls NP Road and the Great Central Road and nothing rattled loose or played up in any way.

Our friends in a 200 series Land Cruiser, on the other hand, did not fare so well when it came to electrics. Following local advice he had a Ctek DC-DC charger installed professionally by a very large and well known auto electrician here in Newcastle. They also installed an auxiliary circuit for his fridges and accessories etc connected to the aux battery.

In short the system never worked properly. Initially the DC-DC was installed in a very hot part of the engine bay making it cut out once the engine warmed up. We repositioned it behind his grill but even then he only got a useful charge on big driving days. On days where we did short trips around camp he was always having problems with a flat aux battery (including the extra aux battery on the trailer). To further add to his woes the auto elec did NOT install any form of low voltage protection on the circuit for his fridges and accessories. He ran his batteries far too low a few times and it didn't take long for the aux in the engine bay and the aux on the trailer to both die completely.

He couldn't believe how well our systems worked. So he was wanting to find out a little more:

Feel free to use my feedback as a testimonial if you wish.

Thanks

The guy with the Toyota has now had one of my DBS in his vehicle for a year or so and has not had one of the problems he suffered with, when he had the DC/DC device fitted.