Thread: Traxide SC80 Battery Controller

Sure...

But without going in to a twenty page expanation, basically...

Something along the lines of the BCDC 12v charger elimantes any issue of voltage drop. Voltage drop isn't the only issue with charging a battery ina camper the distance is too. Basically, (very basically it isn't of course quite this simple but..) when your alternator is charging the power "out" will take the path of least resistance, this is why your primary battery can end up charged but your auxillary in the trailer never gets properly charged (also why it is recommended to put the camper battery on a decent charger regularly).

A 12v charger also adresses this issue charging the camper battery as it's own entity, not by simplying linking them together.

For those that just run an anderson back and plug them together for charging, yes it will work, but not as effecitvely from both a battery energy storage point or view as well as battery life span.

Again this is simplified, but an overview of why it is a "better" rather than just another way of doing it.

Hi cookiesa, and while I did not reply to your fist post and most certainly replying to this one.

The bulk of your post is fresh of the advertising hype used to sell DC/DC devices and while is all sounds good and well, the single factor that is “ALWAYS” omitted when some one is promoting these devices is the fact that they are only good for topping off battery that are only been used a bit but if the battery, and I emphasis a single battery, if the battery is in a low state then unless you are driving long enough you are not going to get any additional advantage from these devices.

With a low battery, it is highly unlikely that you will drive long enough to fully charge it no matter what type of charging you use.

Furthermore, when your off on that long holiday, WHY DO YOU NEED TO FULLY CHARGE YOUR BATTERY.

This is one of the myths the sellers of these products try to promote and while their devices are in no better position to fully charge a battery if the battery is low and the drive time is too short, they try to give the “illusion” that their device will fully charge your battery.

In the few instances where one of these devices could fully charge a battery quicker than an alternator, it’s only because you have stopped driving before your alternator has had a chance to fully charge the battery.

So you have spent $400+ to gain, at most, maybe a 10% advantage, and again, this is only if you don’t drive long enough to give an alternator time to fully charge the battery.

So for $400+ you now have at the very most, 10Ah more battery capacity. That’s one hell of an expensive way to get such a little extra capacity, and again, this is only in a few cases, not the majority of cases.

In the case of a house battery in a camper trailer or caravan, a far cheaper set up improvement, with much greater advantages and is must kinder on your batteries, is to fit a second house battery.

The simple addition of another battery gives you additional capacity, and if you had a single 100Ah battery and used all 80% available, which takes your house battery down to 20% SoC, by adding another 100Ah battery and using the same amount of capacity only takes your two batteries down to 60% Soc and it will take your alternator hours less time to bring two 100Ah batteries to a fully charged state than these DC/DC devices can bring either a single 100Ah battery up from 20% SoC or two 100Ah batteries up from 60% SoC.

And there are heaps more advantages to be gained by simply adding a second battery, advantages that these DC/DC devices can not give, and the second battery system is usually cheaper the set.

Cookiesa, as I have posted many times, there is more than one way to skin a cat and these DC/DC devices are just one of a number of option, but they are the most expensive for the smallest improvement, if there is actually any improvement at all.

OH CRAP NOT DC-DC CHARGERS AGAIN!!!!

Going outside to hug my USI160.

It is not adverting hype but in fact very solid scientific fact based on research done by botrh companies such as REDARC, Century and exide here in Australia, no doubt duplicated in other countries.

But then again you have a vested interest in pushing your ideal. I also haven't touched on load sensing ECU based alternator charging and the like which also introduces a whole different set of issues with just linking two batteries together.

There are several methods as you say, and indeed one of the reasons there is no "one set up" suits all.

Great idea having two batteries, extra capacity and a longer charge time! (The last stages of charging are much slower than the initial bulk charge, but hey you know that, just failed to mention it in this post)

The other factor is what type of battery/ies you're using .... some recharge faster than others ... Optima Yellow Top AGM's for example, can be recharged lightning fast compared to a wet cell deep cycle style battery ... so the Yellows will recharge faster on a shorter drive.

Adding a second battery is of great benefit. Dual 100A/Hr batteries at a 10A discharge (5A/Hr each) for 5Hrs will leave more charge in each battery than a single 100A/Hr battery at 10A discharge for 5Hrs ... the slower the rate of discharge of each battery, the more A/Hrs the battery can deliver ... therefore dual batteries will need less A/Hrs to recharge for the same discharge as a single battery.

An extra battery (dual batteries) vs a single battery won't take longer to recharge if the discharge was the same. It will take less time.

Hi and thanks Fluids.

Hi again cookiesa, and if there has been “solid scientific research” done, why don’t they post up the results when the promote these devices. Lets face some REAL facts, if such research has been done and the results were so in favour of these devices, they would have already been posted up and used in their advertising.

What such research would show is that yes, these devices can fully charge a battery, but for the research to be relevant, it would have to show a comparison between what these devices can do as to what an alternator can do, in the REAL WORLD.

First off, because an alternator can automatically adjust the amount of current being produced, an alternator will increase it’s output if there is an additional battery added to the set up, and as an alternator can increase it’s current production, the two batteries will be charged in about the same time a single battery is charged.

With the above in mind, if the two batteries are only discharged down to 60% SoC, an alternator is going to fully charge them, to 95% or better, hours quicker then a DC/DC devices can bring a single battery, discharged to 80% SoC to a fully charged state.

Now alternators, because they use constant voltage charging, as the battery nears a full state, the charging current tapers off, and means it will take a lot longer to fully charge the two batteries much passed 95%.

But cookiesa, you neglected to mention the fact that DC/DC devices and multi stage battery chargers also step back the charging current once the battery reaches about 80% SoC, and so it would seem that these devices have to copy what an alternator does naturally.

Next, as I have already posted, it is highly unlikely that a house battery in a low SoC at the start of a days drive, will ever be fully charged while driving, no matter what system you use.

So cookiesa, while you are making claims that these devices better charge a battery than an alternator, which while in a laboratory might be the case, it is not so in the REAL WORLD, and as such, can you post up a link to any battery manufacturer, including Exide, where they state that their batteries must be fully charged every time they are use or the battery’s life span will be affected.

Now for some REAL facts, first off, it is not necessary to fully charge a battery every time you use it to get maximum life out of the battery, a fact that is stated on the SuperCharger battery site in the info on Allrounder batteries.

One little bit of info that seems to have CONVENIENTLY overlooked when comparing a single battery + DC/DC devices with a two battery set up using the same amount of power, is the fact that the lower you discharge a battery the short the life span for the battery.

This info is available on just about every battery manufacturer’s web site.

So once again, needing to discharge a single battery down to 20% SoC is actually quite harmful on a battery, while the two battery set, because you only take them down to 60% SoC for the same amount of power used, is, according to all battery manufacturers, far more beneficial for the batteries.

Furthermore, in a single battery set up, all the load is coming from one battery, in a two battery set up, the load is spread over the two batteries and is reduced by at least half.

Another fact is that reducing the load on any battery will help extend it’s life span, so again, the two battery set up is far more beneficial for the batteries than a single battery + DC/DC device set up is.

There are situations where these devices have a use, but to claim they will do a better job than what an alternator can do is simply not the case in the vast majority of set ups.

I'm wasting very little time in this my last response, you have an agenda to push and will continue to do so..

EXIDE..

To help maximise the life of your battery, follow these helpful tips:
Keep batteries topped upMaintaining a sufficient electrolyte level ensures the electrolyte is neither too high or too low. Use distilled or deionised water and never over fill. Maintenance free batteries will usually not require topping up. Low maintenance batteries require the addition of water only once or twice per year depending on conditions.


Batteries have a limited shelf life and when stored gradually lose their power to perform. On average, a fully-charged battery takes about 13 weeks to gradually discharge to less than its optimum operating level.

Whilst in storage batteries that have not been recharged and allowed to go flat, may be permanently damaged. Recharging every four to eight weeks, depending on storage conditions, will restore batteries to "as new" condition.

Also quite common knowledge.

The use of a DC/DC charger was mentioned in relation to fitting them ina camper or similar where voltage drop is a big consideration. As mentioned by Fluids, battery type makes a big difference, which is why it is preferable to not mix battery types with basic isolation systems. Something a DC/DC charger can also overcome.

As I said, horses for courses but obviously you are incapable of believing any product other than yours may be better in the correct context.

There is nothing wrong with your system, if used appropriately, but there are other systems out there, some of which will be better in some circumstances than yours. But hey, keep flogging away.

You also mention alternator output, love that one as most new vehicles now have ECU controlled alternators that are no where near as good at charging extra loads, and in some cases if wired traditionally won't charge them at all.

The biggest limiting factor in charging is the battery itself, just because you have a 100amp alternator (good luck actually getting 100amps out of it in "real life"). The battery will not take a 100amp charge. (With the exception of some specialty batteries)

As for charge times on a twin set up the charge will take longer, regardless of the system used than a single battery due to the batteries own internal resistance which will increase as the battery gets closer to being charged.

But yes twin batteries will last longer as you are not cycling them as deeply (assuming comparing apples with apples)

Over and out

Cookiesa, mate, I don’t know if you’re try to have a lend of us or that you are really that naive. The info you have in bold print relates to keeping the electrolyte in the battery topped up and has nothing to do with charging the battery.

Again, what does having batteries fully charged before storing them, have to do with charging them while driving.

Also, while it may be a problem trying to charge paralleled dissimilar batteries with a DC/DC device, because they use constant current charging, this is one of the big advantages of using an alternator.

An alternator, as posted earlier in this thread, is a constant voltage charger and as such can charger any mix of dissimilar batteries and any mix of batteries with different States of Charge, and every battery in the set up will be charged at each individual battery’s own optimum charge rate.

You sure as hell can’t do that with either a DC/DC device or a multi stage battery charger.

So once again, there is a very large advantage to be gained by simply using two auxiliary/house batteries rather than the limited use a single battery + DC/DC Device offers.

And once more and in more detail, because you obviously don’t understand how an alternator works, an alternator can charge two batteries in the same time it takes to charge one, PROVIDING the alternator is big enough.

So if you have two low 100Ah batteries and you want to charge them from an alternator, then as long the alternator is 80 amps or bigger, you will easily charge both batteries in the same time it would take the same alternator to charge a single battery, and you would still have enough power for the rest of the vehicle’s normal requirements.

Where as, if you have a 20 amp DC/DC device, thats all you have and if you need to add a second battery to your set up, you now have a situation where it will take you nearly twice as much driving time to charge the two batteries while the same set up with an alternator will take no longer.

And one more point, so far you are the only one that tried to compere my isolators with DC/DC devices, I have been talking about standard isolators in general.

BUT, if you really want to compere my isolators and what they can do, your DC/DC devices are going to look like nothing more than an expensive joke.