DC to DC Chargers

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Re: DC to DC Chargers

This forum, as with many others, has some quite vocal people who are quite focussed on only one way of doing things.
There is always more than one way to achieve what you want. It sometimes just takes a bit to sift through all the info

And sorry Damain, but you are a perfect example of being focussed on a single solution and you are also proof that the biased misleading advertising used to flog these DC-DC devices is working.

Some facts on just one of many options available.

For far less capital outlay you could simple add a second battery.

Even using the same amount of capacity as you would with your DC-DC set would mean discharging the two batteries to only half that needed for your DC-DC set, which means your battery has to be worked twice as hard, which in turn means a shorter life for your single battery set up.

Because the two battery set up is only discharged to half the depth your DC-DC set up discharges your single battery to, the two battery set up will be charged in a shorter time than your DC-DC set can.

Again, because you have two batteries, you are only drawing half as much current from each battery and the lower the current draw, the easier it is on each battery, so again, the longer the batteries will last over your single battery.

There is also the obvious advantage of the two battery set up, you have heaps more power available if you need it.

Whereas with your DC-DC single battery set up, if you find you need more power than you have available, you have only one option and thats to add another battery ( more additional costs ) and the instant to you add a second battery to a DC-DC set, you also have to factor in up to 90% more driving time ( again more additional costs ) to allow your current limited DC-DC device time to charge your two batteries.

I am not against the DC-DC devices, there are some situations where they can offer some advantages, it the way they are marketed that is the problem, using grossly misleading advertising hype.

And Damian, as you can see, there are far cheaper, more effective ways to achieve better results than these devices can do, so before you accuse others of being single minded, you need to do some homework about your own ideas.

[Damienandwendy Junior Member Find all posts View Profile Close Damienandwendy]

Re: DC to DC Chargers

Hi Drivesafe, (notice how I at least take the time to spell your name correctly even though you misspelt mine twice)

At no point in my post did I say that DC-DC chargers were the only solution. I suggested 2 uses for them as well as alternator charging. And I described parts of my setup of which you have decided to make several assumptions.

So to allow my alternator to more effectively charge my house battery in my camper trailer (the battery attached to my DC-DC converter) you are suggesting I would have been better off buying a second battery ?
I only had room to install one battery so that was out of the question. The idea has some merit if you have the room but in my situation it does not.

My main point was that by using a DC-DC charger on your one house battery you will be able to use a lighter duty cable then one using purely alternator power.
I agree that a 20A or 30A DC-DC charger may not be the best option if you need to charge multiple batteries, but if you often need more power than what you have available, the you haven't done your homework in the first place and looked at your present and future needs, and planned your system to suit.

And thanks for the point about homework, because that is what this is all about.
I did mine and developed the system I have and I am very happy with it.

cheers

Damien

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Re: DC to DC Chargers

So Damien, what your saying is that everybody who buys a caravan or camper trailer knows the exact amount of power they will ever need before they buy, so they will never need to upgrade their stored power capacity.

The reality is that a vast majority of RV users, even when they have a good idea of what they will need in the way of house battery capacity, will allow for future expansion of their stored power capacity.

And to make for more problems, if the caravan or camper trailer was fitted out properly in the first place, they wouldn’t be fitted with incorrectly undersized cable but as many RVers know, it is a sad fact of life that many RV manufacturer’s don’t have a clew what size cable is required when it comes to wiring for the house battery in a caravan or camper trailer.

And then to make a bad situation even worse, you are indicating that someone setting up their van or CT can now use lighter duty cable if using one of these DC-DC devices, this just shows a total lack decent planning for the future in your set up.

It is far cheaper to rewire to the correct size cable and then not only is the set up more effective, it again, means that expanding the stored battery capacity is already catered for.

And Damien, while you may be in the extremely rare position of having such a poorly designed set up that will not allow for future expansion of it’s house battery capacity, but the majority of of vans and CTs will easily accommodate two or more additional house batteries and many actually come set up for such expansions.

And from hands on experience, many RVers double and triple their stored house battery capacity within a short period of time after purchasing the van or CT and it’s not because they didn’t do their homework, situations change and the most common reason for needing to increase RV house battery capacity these days, is because the user finds they what to do more and more free camping than they originally planned for, so they will increase their house battery capacity to meet their charging needs.

Admittedly, in your case where you haven’t looked to the future and you have set up in a manor that will not allow you to easily expand your house battery capacity, then a DC-DC device may be your only option but this just means you have not set up properly in the first place and your set up puts you in a very small minority situation because as posted, from hands on dealing with many thousands of customers, expanding house battery capacity at the time of purchasing or after using their RV for some time, is now very common place.

These DC-DC devices have their place BUT they are NOT the end all answer to most RV set ups, they can actually create more problems than they resolve.

[Damienandwendy Junior Member Find all posts View Profile Close Damienandwendy]

Re: DC to DC Chargers

Once again Drivesafe, you are missing the point of what had to say - and that was that DC-DC chargers were an option depending on your situation, setup and needs.

For you to come an now attack my "poor setup" and lack of planning is lame at best.

I have a 150Ah AGM that is more than suitable for the electrical needs that I have present and future. This size battery allows me approx 3 days of camping only using 50% capacity of the battery, which although not ideal, is not too deep a discharge to overly shorten the life of the battery. A future purchase of a solar panel or two will allow me to extend that a little further. In touring mode with around a 1 to 2 hour drive every day or so, my battery would always remain very close to fully charged.

As far as I was aware, the main purpose of these forums is to give people ideas on different options that they can look at for their personal situation.

I have tried to do that by describing the way in which I have set up my system, but you have turned it around as a personal attack on my lack of planning and poor choice of camper purchase, etc.

Lets just stay with providing information and ideas please.

Damien

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Re: DC to DC Chargers

but if you often need more power than what you have available, the you haven't done your homework in the first place and looked at your present and future needs, and planned your system to suit.

Hi Damien, if you have taken my comments as an “attack” on your reply, then try considering your comments above.

The reality is that most people will never know what sort of power requirements they need until they get out there and start enjoying their set up and comments like yours show just how little you know about this area of RVing.

[Guest Close Guest]

Re: DC to DC Chargers

Please keep to the topic guys, Personal attacks will be rewarded with holidays from the board... Last word on this.. :!:

[humphrey Junior Member Find all posts View Profile Close humphrey]

Re: DC to DC Chargers

A spirited discussion, although I still have no idea what a DC to DC Charger is. I'm assuming its similar to a an iPad? I wouldn't know what I need if for, but someones made it for a reason and everyones buying them so I must need one too.

It makes me think back to a Leyland brothers show I once saw. Must of been late 60s early 70s and they crossed the Simpson in what must of been the first ever Patrol brought into the country. It had all the modern conveniences like 4 wheel drum brakes, powerless steering, key required entry, a 3 speed fan/heater and vinyl seats.

My initial thoughts were of a couple of idiots heading for certain death. There was not one GPS unit between them, no lift, no HID's, no diff lock, no inverter/dual battery deep cycle set up, no Waeco, no generator. How far did these guys think they were going to get? Mals dress sense gave some explaination, I mean what sort of fool would cross the Simpson wearing a pair of Stubbies? I could only think that if your going to perish in the desert, you might as well be comfortable.

So after numerous dunes the Patrol finally grids to a halt when the clutch fried. (I noted that one of the women were driving at the time, but going down that road leads to dangerous ground.) This it it, the beginnig of the end I thought. "Serves yourself right" I yell across the lounge to the TV, "if you'd installed a heat exchange shower system and battery monitor this never would of happended". Funilly enough Mal pays no attention to me and pulls out a 2way radio made of baling wire and a coat hanger and orders in parts from a local station. He then makes me look even more stupid as he pulls out the old clutch, puts in the new one and continues on his merry way. I tell myself it was a case of shear arse over good management on Mals behalf and I went back to running 300 metres of cable through the Prado so I can run all the esentials that are required for the following days 4 wheel driving..............100 kays out of Melbourne.....................with full mobile phone coverage.............................and enough 4x4 traffic to resemble the Monash Fwy during peak hour.

People would once cross the country on horse back. It seems now days we cant manage it without 3 phase power.

It made me think that some times less is more.

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Re: DC to DC Chargers

Thats good entertainment value Brett.

Cheers.

[Matty80 Avid PP Poster! Find all posts View Profile Close Matty80]

Re: DC to DC Chargers

Fantastic! Absolute gold... Can really put it all back into perspective...

[Damienandwendy Junior Member Find all posts View Profile Close Damienandwendy]

Re: DC to DC Chargers

Interesting point Brett, but I guess the fact is that more and more people are expecting to take more electrical gear out bush to make the "camping" experience more enjoyable or comfortable. Late last year a friend wanted to know if his wife could take her 240V hair dryer out bush so she could dry her hair. I then asked him if he was camping in a tent or motel.

People want more power, and a way of maintaining that power so they can be out and about for longer.

Redarc have some good info on DC-DC chargers if you really want to know what they do. At the moment they have a 20A charger and are about to release a 40A version with the ability to charge via solar panels as well which could be interesting if its not overly expensive. But I reckon it will be.

Cheers

Damien

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

Re: DC to DC Chargers

hunphrey wrote
He then makes me look even more stupid as he pulls out the old clutch, puts in the new one and continues on his merry way.

I haven't seen that episode but I reckon someone else besides those guys actually did the work. My old man used to run a towing Business when i was a kid. He once Collected both of the Leyland brother vehicles (when the had Jeeps). They had broken down around Marla and he carted them all the way back to Whyalla to repair the Jeeps. One had a broken axle, don't recall the problem with the other. Both were nice blokes and made good TV, but between them they couldn't work out which end of the screwdriver you should use to take the wheelnuts off. :wink: He used a traytop truck towing a three axle, two car car trailer for these recoveries, on that same trip he also collected Bill Peaches caravan which had also broken down, another broken axle.

EDIT: just to get back on topic, I run a triple battery system, cranking battery, AGM in rear of prado and batteries in both a camper trailer and a tip trailer. After reading lots of info; mostly on this site, i couldn't work out why i needed a DC DC charger. All i have is a redarc isolator and wires connecting them all and it works very well.

Cheers Andrew

[stumped Lurker Find all posts View Profile Close stumped]

Re: DC to DC Chargers

thanks aj120 after reading all these posts and being a absoloute novice your post made the most sense i will be putting a redarc isolator in my new prado thanks

[AJ120 Out of control poster! Find all posts View Profile Close AJ120]

Re: DC to DC Chargers

thanks aj120 after reading all these posts and being a absoloute novice your post made the most sense i will be putting a redarc isolator in my new prado thanks

When i researched this topic I got just as confused as most people, so i decided to apply the scientific principle known as "Occam's Razor" there are varying interpretations of this principal but basically it says, If there is more than 1 answer to a problem then the simplest one is most likely to be correct. The other theory that backs this up is the KISS theory, "keep it simple stupid" :wink: I should add that as i have a D4D i have also fitted the voltage booster diode that LeighW makes.

Cheers Andrew

[Gumnuts Lurker Find all posts View Profile Close Gumnuts]

I just ordered a kit from Derek at ABR-sidewinder and dropped it in. Isolator, voltage booster diode & Optima D34 battery. Works a treat! For the last 19 years of camping I've only ever taken a swag, an esky full of ice, a battery powered transistor radio and a gas latern. It's only the arrival of kiddies that I thought I would try the luxury of 12 volt power. Seems a shame to say goodbye to the good old days though.

[NewyD4D Lurker Find all posts View Profile Close NewyD4D]

I run a Ctec DC-DC charger with an Optima yellow top 55ah 2nd battery, I am very happy with this set-up have never had a battery voltage issue or warm beer!