solar charging

Peter,

Thankyou for your offer of guidance.

Here is the link to my photos https://skydrive.live.com/?sc=photos&cid=65f662d236b5d109#!/?cid=65f662d236b5d109&sc=photos&uc=4&id=65F662D236B5D109%21135

The solar side of the trailer wiring are the last few photos - including the solar regulator inside the trailer as well as the one mounted on the back of the folding panels.

My husband was thinking of bypassing the regulator on the back of the panels by simply disconnecting it, and then plugging in the anderson plug to the connection in the trailer that is wired to the internal regulator ....... would this give us the optimum charge possible to the batteries from the solar panels!

Thankyou again,

Lenita

You're most welcome Lenita,

looking at the photos, you can see the solar panel input +/- on the left of the solar regulator mounted on one of the panels.
Next to the solar input +/- you can see the battery +/- terminals with the extension wire on them.
Disconnect all four wires from the solar regulator and join the solar panel positive with the extension wire positive, same goes for the negatives.
I recommend marking each positive wire first so you don't mix up the polarity.

All the best.
cheers, Peter

Thankyou so much Peter! Very helpful advice.

I hope you don't mind me asking you one more question - this actually relates to the anderson plug from the car alternator which charges the batteries whilst driving - should we purchase a DC -DC Ctek charger to maximise the charge to the batteries from the car?

We intend to bush camp most of the time - only occasionally visit caravan parks - and even then we tend to prefer unpowered sites since we don't really enjoy being on a concrete slab sandwiched in between large vans! So charging the batteries via 240volts will be on an infrequent basis whilst camping.

Or would it make more sense to purchase a 15amp 'converter' (or whatever it is called!) and charge the batteries at home on 240volts rather than relying on the solar panels?

Cheers,

Lenita

Anytime Lenita,

depending on the voltage setting of the car alternator, the batteries will be charged to about 80~85% full pretty quickly. A DC/DC charger may get to this stage a bit later, but it'll push the state of charge to 100% within another 2~5 hours of driving.
So it all depends on how much you drive, but if you're more stationary than driving I'd say solar is the better option. The problem with the ctek is that it doesn't get the absorption/float switch over right. This means the batteries can get overcharged on any drive lasting longer than say 2 hours, if the batteries were already fully charged at the beginning of the trip. This overcharging issue is even more severe if a fridge is connected to the batteries in which case the ctek will stay in absorption charging mode (at the higher voltage) while the fridge compressor is running, regardless of state of charge.

The advantage of solar is that it can work nicely in tandem with the alternator.
The alternator supplies the bulk of the charge at a high rate, and solar is there to top it off. Topping off the charge only requires moderate to low current, over a long period of time. And that's where solar comes in handy.
Because topping off the charge needs to be done in a precise way in order not to over- or undercharge the battery, the role of the solar regulator is an important one and it should have the following features:

Temperature compensation through battery mounted sensor.
Correct absorption/float switch over.
Immunity of the multistage charging algorithm to intermittent or constant loads while charging.
Cumulative absorption stage charging (that's the only way to account for varying loads and sun intensity during charging).
As a bonus, it should offer a remote control/display option so that you can actually see the amp hours (or Watt hours) going into the battery, and out, voltages, currents, battery temperature, and other variables.
What's also nice is true MPPT (maximum power point tracking) capability which can extract close to the maximum rated solar power from the panel. It's like having a 20~25% larger panel if you compare it with an ordinary PWM solar regulator.

I guess your last question relates to mains powered charging?
Yes, these are always good to have whenever you've got access to mains power, or a generator.
But looking at your setup, you've already got all the ingredients to make this work.
For maximum battery health and best solar efficiency of your panels, you might want to upgrade to a true MPPT solar regulator with cumulative absorption stage charging and battery temperature sensor.
They're cheaper than you think (just click on our profile/web page) - and can certainly save you money in the medium term by extending the life of your valuable batteries substantially.

cheers, Peter

Thankyou again, Peter.

You mention that 'the solar panels can work nicely in tandem with the alterantor' - is this assuming that they are connected whilst we are driving? Since they are portable folding panels, this is not possible.

Or do you mean once we are stationary & have the panels plugged in to keep the batteries 'topped up'?

It is reassuring to hear that our setup has the ingredients to make it work! Although the camper is only 3 years old, it has obviously been well used for outback type camping (which is also our intention!) - plenty of evidence of red dust in nooks and crannies!

From my photos, are you able to tell what sort of batteries are installed? What determines the 'size' of a battery? Is it the measure of its output? If so, how can we figure this out? There are no apparent identifying marks (other than positive/negative terminals) on the batteries - not that we can see, anyway.

There is a 'boost voltage' switch on the solar regulator for 14.4V or 14.7V ..... which one should we choose?

Also, there is an LED display indicating either amps or volts ..... what should each of these readouts tell us about the batteries???

There is another display on the top left-hand side called the 'charging status' - there are two lights - one labelled 'solar power' and the other labelled 'charging' .......... do you know what each of these refer to?

I apologise for our ignorance in these matters - this is our first experience into the world of camper electrics ...... we are so grateful for your (and other's) expert advice.

Lenita

Hi Lenita,

no need to apologise, I'm glad to help.

Yes, solar charging works in tandem with alternator charging, but one after another.
Driving means bulk charging (high current, rapid increase of state of charge up to 80~85% of full). Followed by solar charging while stationary (low current, slow increase of SOC to 100%).
Ideally, you'd be driving for a couple of hours in the morning, and the solar panels do the topping up for the remainder of the day while pulled up somewhere.
But if the solar panels are of sufficient size and the solar regulator is of the MPPT type, then you might not need to drive at all, or you could skip a day or two and rely on solar only. As a guide, your alternator returns charge at the rate of 1Ah/minute.
E.g. if there's a daily shortfall of 20Ah, you'd drive (or fast idle) for 20~30 minutes the next morning.
To get an idea of state of charge, you can observe battery voltage which should reach 14.4V by 2pm.
If it doesn't get there in time, run the alternator a bit longer next morning.

You've gotta love your red dust lol.

Photos show batteries are pretty likely AGM around 100Ah each.
Battery size gives a good indication of its capacity, so yours would be around 300Lx175Wx200H?

For selecting battery size (Ah capacity), you'll need to find out your daily Ah requirement.
Multiply by 2.5 and that's the recommended battery size.

14.4 or 14.7V boost voltage:
Rule of thumb for AGM batteries: if they're being discharged more than 50% on a daily basis, select 14.7V, otherwise 14.4V. You can select 14.7v regardless once or twice per fortnight for a mini equalisation charging stage.
But if there's no battery temperature sensor, select 14.4V in summer regardless of depth of discharge.
The way the regulator's charging algorithm is designed also determines what setting to use, and also how accurate the actual voltage is controlled. Sometimes 14.4V setting only results in 14.2V battery voltage in which case you'd select 14.7V giving you 14.5V actual.

Indicator lights:
these only signal the presence of charging current/voltage, but not how much of it.
A basic voltmeter/multimeter reading taken off directly at the battery terminals is a good proxy of actual state of charge. But this varies with any load currents. An easy way is by using a solar regulator with a remote control/display unit.

Hope to have explained everything?
cheers, Peter

Thankyou for such valuable information and guidance Peter! We very much appreciate your help.

You have anwered our questions in such a way that even I (being a technically challenged female!!) can understand - thankyou.

I am still unclear on only one thing - and that is the LED display on the solar controller in the trailer. It indicates either volts or amps - we have only switched it to 'volts' - from what we can see it is telling us how many volts are currently in the battery (?????). Are we correct in thinking along these lines?

Whilst it is charging, we can see the level going up each time we check (ie 12.5 up to 14 .....or thereabouts).

We haven't actually switched it to 'amps' - what would that tell us?

Lenita

And, yes, we do love that red dust!!! Our previous car - a white 2WD Mistubishi Magna - wore its unremoveable layers of red dust with pride!!!

No worries Lenita,

I'm pretty positive the 'Volts' are the battery voltage (to be double checked with a multimeter right across the battery terminals).
The 'Amps' is most likely the charging current.
You can verify this by watching the amps during charging, with no load connected. If it's showing some amps, then these are charging amps.
If not, then they're load amps. Load amps show up on the display whenever a load is connected to the solar regulator and switched on - check this at night with no sun to exclude any ambiguity.

cheers, Peter

This is for Peter (battery Value)
You said :- The problem with the ctek is that it doesn't get the absorption/float switch over right. This means the batteries can get overcharged on any drive lasting longer than say 2 hours, if the batteries were already fully charged at the beginning of the trip. This overcharging issue is even more severe if a fridge is connected to the batteries in which case the ctek will stay in absorption charging mode (at the higher voltage) while the fridge compressor is running, regardless of state of charge.

Question is - (1) is this only for ctek as I have bought a redarc DC-DC multi stage charger with built in MMPT solar regulator.
(2) And where should it be installed, close to the alternator or near the 2x 100ah agm batteries in the camper trailer or it does not matter as I would prefer it in the Camper as I already have a 2nd battery under the bonnet
Thanks for your help

Hi Tony,

I just read up a bit on this unit of yours.
It seems to switch over to float once the output current drops below 4A, or after a 'predetermined' time. It seems to switch back to absorption if a load current exceeds the switch over threshold, so there's also potential for overcharging albeit the chances are much lower than for the ctek simply because the ctek's switch over threshold is so low.

Solar charging:
Their MPPT only seems to work for 12V rated panels.
And their explanation of the MPPT algorithm is a bit weird:
"MPPT ensures that you get the most power
possible from your solar panels during low light
level conditions."

Why can't they say something more clear cut like this:
A true MPPT solar regulator is capable of extracting close to 100% of available solar power regardless of panel voltage. Since the panel voltage moves up and down with cell temperature, the maximum power point shifts up and down as well giving it the name MPPTracker.

Because this unit can only utilise 12V panels, there's a good chance that their 'MPPT' functionality is limited to a preset voltage somewhere between 16~18V.
Of course this is a half baked approach because it can't take advantage of higher panel voltages with their reduced wire losses.
And did I miss the max specced solar wattage?

Other things I dislike:
float charging voltage is set to 13.3V - this is too low for any VRLA battery, especially for AGM types. Battery life will be compromised due to the effects of undercharging.
No battery temperature sensor input, although the manufacturer is based in a country with temperature extremes - you would assume they'd know better.
Then it doesn't provide a load output with low voltage cutout - any el cheapo solar regulator has this feature standard.
40A rated: ok, but for how long is the DC/DC charger able to churn out this high current?
Instead of an answer, you get to read this:
'The current in Boost stage may vary during operation in order to maintain safe operating temperature..'

Ok, so what's a safe operating temperature for electronic fanless devices weighing only 680 grams, which generate about 60 Watts of heat during 40A/12V DC/DC conversion?
Or how long before 60 Watts push the temperature up by 40 degrees?

Many questions remain unanswered but if you asked me if I would recommend it to our battery customers, the answer is clearly no.

Where should you install it?
Because it can tolerate a low 9V at the input, but the output only gives 13.3V float, wire it as close to the battery as possible.

cheers, Peter

Thanks again, Peter,

We will do as you say & check to see if the 'amps' display is the charging amps - and also double-check the voltage using a mutimeter (ha - once my husband has figured out how to use it!!).

Cheers,

Lenita

Thanks for all your expertise on solar/battery matters. I have purchased the redarc dc/dc charger already being told that they are 1 of the better one's on the market and Australian made. Which/what should I have brought ?
When you say near the battery is that the one under the bonnet or (I suspect the one in the camper as you say it tolerates the low input)
Again your expertise is invaluable
Thanks

Peter,

pardon my ignorance but why would "float" voltage of 13.3V affect the longevity of the battery. Isn't "float" one of the later stages after Boost and absorption when the battery has been largely or fully topped up?

Charging Algorithm

• When the BCDC1240 is turned on, it will move into the bulk charging stage called Boost stage. Boost stage maintains a constant current until the battery voltage reaches its set point. The current in Boost stage may vary during operation in order to maintain safe operating temperature, or to limit the difference between input and output voltage.
• The charger will then move to Absorption stage. This stage maintains a constant voltage level for a predetermined period of time or until the current being drawn by the output drops to less than 4A for 30 seconds; after which the charger will enter Float stage.
• Float stage maintains 13.3V on the output battery, keeping the battery topped up. This counteracts the battery’s self discharging. When a load applied to the battery causes it to lose charge, the charger will move back into Boost.

From the Redarc BCDC 12/40 spec sheet the solar voltage thresholds appear to be 8 - 29V. I'd imagine that as maximum open current production can be around 23-25V from a 12 volt panel that this would have been taken into account by the manufacturers.

Again, I'm no expert but as a serious outback traveller who spent a lot of time researching and a lot of money ensuring I got a power system to suit my needs, I've found Redarc products to be exceptionally good. Their aftersales service is also excellent.

Cheers Mick

Hi Tony,

yes, near the battery in the camper.

The Redarc DC/DC charger is pretty much useless in its current version and it's also going to harm any VRLA battery (gel or AGM), and also flooded type to some extent (especially when it's cold) due to the fixed low float charging voltage.

There's actually no need to install a DC/DC charger because bulk charging can be taken care of by the alternator, and absorption/topup charging can be done by a properly setup solar regulator.
If the sun doesn't shine for some time, no dramas as the battery can ride out these overcast days, relying on the charge from the alternator.
There's more details in Followup #6 above.
An isolation solenoid switch can be useful, but not absolutely necessary.
Instead of using such a gadget (which is bound to fail at some stage), take a pair of 2B&S wire and a 200A fuse (less than 10 bucks) to connect the starter battery and the house battery in parallel.
If the house battery is in the van, use 6B&S wire and a 80~100A fuse (the lighter wire saves you money and also fits in an Anderson plug).
The solar regulator rides on top of this battery combo, most easily wired in parallel again. Use the solar regulator's switched load output which prevents deep discharge of the starter/house battery combo so that you can't inadvertently flatten both.
Install a voltmeter on your dash which allows an estimate of state of charge in both your starter and house batteries.
Only install an isolation switch/solenoid if you want to discharge your batteries below 70% SOC on a regular basis (this is kinder to the starter battery, at the expense of the house battery).
Simple enough?

@Mick,

I'm sure after all those years they finally got their isolation switches right.
But now, with their new DC/DC charger, it appears they're at the bottom of the same steep learning curve again.

cheers, Peter

cheers, Peter

Peter, ok sounds like I will not be installing the dc/dc charger. But don't you loose to much voltage over a long distance (6mtr) to camper battery from alt.
And can we when setting up at camp just plug the solar panel in via the Anderson plug on camper to top up camper batteries, as we stay bush camped in same spot for 2 to 5 days before moving off again. The solar panel that we have is 160w mono folding with (seems only a cheap controller fixed to the back, I may need to buy a better MMPT controller and fix it at the end of cable just before Anderson plug
Is this correct its all new for us. I'm a mech fitter no nothing about electricity but willing to learn !

Hi Tony,

no worries, I'm glad to assist:

I give you an example for voltage drop:
6B&S wire (resistance 1.4mOhm/metre), 12m x 1.4mOhm=17mOhm plus 10mOhm for plug and fuse = 27mOhm all up. At a charging current of 30A, voltage drop is close to 1V. BUT, because the charging current tapers off as the state of charge rises, voltage drop reduces steadily, and in the end the battery voltage equals the alternator voltage which may be somewhere between 13.8 and 14V.
Only if there's a load like a fridge connected during charging, this would intermittently lower the charging end voltage. In the example above, it would lower it by about 0.12V but only while the fridge compressor runs. Nothing to lose sleep over.

You can permanently leave the MPPT solar regulator connected to the van battery (and starter battery if no isolation switch).
Whenever you're stationary, just plug the folding solar panel (you can wire it up in 2x12V series configuration for maximum charging efficiency) into the MPPT solar regulator (plugs supplied) and the precision charging algorithm takes over. The el cheapo solar regulator on the back of the panel is easily bypassed.

For more details, circuit diagram etc, just get in touch with us through the web site linked in ourBattery Value EO profile

Looking forward to receiving your reply.
cheers, Peter

It appears those who use the RedArc BCDC1240 seem to understand it much better then those who don't and those who don't understand it seem to make comments using assumptions only.

The main reason RedArc don't go into detail about charge characteristics is because 95% of people don't want to know the in's and out's and they admit they know very little about how or why something works... 3% of people want to know everything but don't understand it..... 1% think they know everything and make comment about something they think the know something about.... and last you have the lonely other 1%er who know how it works and understands it but unfortunately get knocked down in flames by people who think they know a lot about everything!... but seem to know a little about nothing.

Give someone 10% of the information and they will understand 99% of it... give someone 99% of the information and they will understand 1%.... give someone 100% of the information and they turn into an expert.

Maybe when your in Adelaide Peter you might care to drop into RedArc and have a tour of their manufacturing and test facilities and speak to one of their many engineers.

If you want a introduction just hollow and I can arrange it for you.

And Mick you spot on with your detailed description of how it works and yes the MPPT is set at 29Vdc after we had concerns Re thier BMS alarming at 25Vdc when used on 28V panels..... thanks for reminding me I have to do a firmware upgrade on our test BMS to accept 28V panels.

Oh and something else Peter you asked about re: case temp.

Redarc have developed with I think 3M or Dow Corning a special heat absorbing encapsulating compound to aid in heat removal/transfer, water proofing and vibration.

Basicly the assembled boards are submerged in this goo and left to set, they had some remarkable results after subjecting it to the harshest environment in their computer controlled environmental test chamber.

It's amazing with the technology something that was near imposable to do 3 years ago can all of a sudden be accomplished efficiently.

Peter one last question what have you heard about silicon batteries and have you got any inside information.

Talk about reinventing the wheel.

olcoolone, thanks for the lough!

teamed up with 3M or Dow? hohoho

Mate the technique of potting electronics is around for decades and you seriously want to make us believe they've developed this in the last 3 years?

Check out some facts for a change:

http://patents.com/us-4564562.html

And what's that please:

..and yes the MPPT is set at 29Vdc after we had concerns Re thier BMS alarming at 25Vdc when used on 28V panels..... thanks for reminding me I have to do a firmware upgrade on our test BMS to accept 28V panels.

28V panels yes? And BMS alarming at 25V? just gibberish.
This is not the lingo of an engineer.

And here are some hard engineering questions you can forward to them if you know someone there:

What's the maximum solar wattage the solar regulator can convert to charging amps at a conversion efficiency of 95% or better, based on a 12V battery.

What's the maximum solar voltage on the PV input, it can convert to charging amps with the MPPT fully operational.

For how long can it sustain the claimed 40A charging current of the DC/DC section.
What's the thermal resistance of the unit in °C/W, and what's the DC/DC conversion efficiency.

Then ask them, if they actually understand batteries.
If the answer is yes, ask them why on earth they select a float charging voltage of 13.3V.
Then ask, what in their opinion the temperature compensation for a typical AGM battery might look like, and why they think it isn't important to include this feature in their product.

Olcoolone, if you think, it's such a high specced unit, why didn't they include a readout showing Ah in/out, currents/voltages?
Oh, I know that could lead to information overload.
And what better way to hide its shortcomings, just let the guys from marketing come up with some nice brochures which appeal to the masses.

You ask me about silicone batteries?
Please post links to peer reviewed articles, patents, and other concrete information.
Otherwise it could end up like this DC/DC baby by Redback - more snake oil than substance.

cheers, Peter

Peter do you own homework and why don't you ask them, your the one making assumptions on something you haven't got all the data for.

You must be an engineer... if not why do you act like one.

Peter if you were smart enough to look at RedArcs site you would see they do do one with a very comprehensive read out .... it's called the "BMS"

I suggest you might want to develop your own unit seeing nothing is good enough according to you own thoughts.

Mate people are taking your word for gospal and you can not even offer them the right advise.... I had respect for you and what your doing but it seems your just another guy peddling his wears who has no interest in anything else except what you push.

You have already slandered RedArc saying how bad they are and they don't know a thing about what the make.... that takes a big guy with an open wallet.

Funny thing is RedArc is a advertiser and sponsor on this site and I'm sure they will not be to impressed.

Rule 101 of business etiquette"don't make false or misleading comments about someone else's product and especial when you don't have the hard facts and data to back your claim.

Good luck in you quest.

Peter you might want to google "silicon battery"

If you don't know how here is the link.... just click or paste the address into you web browser and push the enter key.

http://www.google.com.au/search?gcx=w&sourceid=chrome&ie=UTF-8&q=silicon+battery

Dear All

I have read the thread post above #89488 regarding the REDARC DC-DC charging products and am disappointed with the comments made as they are an inaccurate representation of our product.

Redarc R&D staff go through a detailed process to ensure that our charging algorithms provide the best charging conditions for the batteries that they are recommended to be used with. We have conducted and continue to work closely with the University of Wollongong to ensure our products charge batteries at the optimum rate to achieve full charge and extend battery life. We also have a Patent for the BCDC in-vehicle charging technology.

Our testing, validation and manufacturing process conducted in our factory in South Australia along with field and third party laboratory testing are exhaustive to ensure we manufacture a great product.

We would like to extend an invitation to members of Exploroz to visit our manufacturing facility in Adelaide and to take a tour of our factory. In this process we will explain how our products are designed and manufactured and to talk through customer applications. We also have a fully equipped camper trailer with vehicle, solar and 240V AC charging capabilities that can be demonstrated.



Our Customer Support Technicians will also respond promptly to emails power@redarc.com.au or by calling us on 08 83224848 with any techical or application enquiries.

Please do not hesitate to contact me should you wish to discuss this further.

Best Regards,

Anthony Kittel
CEO and Managing Director
Redarc Electronics Pty Ltd

Hi Anthony,

I'm glad you take part in this fruitful discussion aimed at shedding some light on the specifications of your product BCDC1240.

Being such a small unit weighing only 680 grams, questions arise as to its sustained power handling capability.

Since all DC/DC converters generate heat, the case temperature of the BCDC1240 will rise until in equilibrium (amount of heat generated equals amount of heat conducted away).

According to the limited specs in the description, the output power is 600W max, dependent on installation.

The user is left guessing, how to mount the unit for maximum 600W power output.
Further, on behalf of the interested community here on EO, may I ask you to provide data for the BCDC1240 showing the relationship between output power and time, in graphical or tabular format.

Questions also arise regarding the solar regulator functionality of the same unit, again due to missing technical data and specifications in your publications 'Flyer' and 'Instruction Sheet':

What's the maximum rated solar wattage the solar regulator can convert to charging amps and what is the conversion efficiency at the maximum solar wattage, based on a 12V battery?

What is the range of maximum power point voltages the unit can handle at a reasonable conversion efficiency e.g. >90%?

What's the maximum rated solar panel voltage at the input terminals?
What's the conversion efficiency of the MPPT circuitry, at maximum rated solar wattage?

And last but not least, how does the charging algorithm look like for the solar regulator?
If multistage: what are the voltage setpoints for float and absorption charging?

How does the charging algorithm handle varying loads and sun intensity in order not to over/under charge the battery?

Seeing that battery temperature isn't being sensed, hence the BCDC1240 can't adjust the charging voltages for maximum battery health and durability.
Do you think this important feature will be made available in future versions of the BCDC1240?

That's it for the moment, thank you for your efforts.

cheers, Peter

Hello Peter

Thanks for your post. I will ask our engineers to prepare a response to your questions and post back for the Exploroz members as soon as possible.

We will also give you a telephone call and run through the items to ensure we have responded to you and your customer's satisfaction.

Best Regards,

Anthony Kittel
Managing Director
Redarc Electronics Pty Ltd

Hi Anthony,

it's been five days now and no response yet, from your engineers.

I presume that proper product specifications isn't something being considered unimportant by Redarc and hope to see them here soon.
For guidance, please refer to my questions raised in ThreadID: 89488 FollowupID: 741651

Thank you in advance for your efforts.

cheers, Peter

Hello Peter

Thanks for your patience. Further to your post above we can advise that the majority of your questions are detailed in our BCDC1240 instruction booklet which can be found on our website.

http://redarc.com.au/static/files/BCDC1240_Instruction_Sheet-A5-3.pdf

We have also provided some extra information for your reference provided it did not compromise our intellectual property.

To mount the unit for maximum 600 Watts power output please refer Page 5 of the BCDC1240 Instruction Sheet. The unit should be mounted to a flat surface close to the auxiliary battery and away from any heat sources. The unit will operate optimally with a heat sink temperature below 55°C with good airflow. At higher temperatures the unit will de rate output current, up to 80°C. Therefore at higher temperatures it will still achieve a full charge however it will take a longer period depending on battery type, size etc...

Please also refer Page 11 of the BCDC1240 Instruction Sheet:

Q. Where should I mount the BCDC Unit?

A. The BCDC should be mounted as close as possible to the battery being charged (generally called the Auxiliary or House battery). If the Auxiliary battery is located under the bonnet, pick a location for the BCDC that is close to the battery and away from any direct engine heat. If the BCDC is to be mounted into a Caravan or Camper, near or in the battery compartment is generally the best position. It is also a good idea to mount the BCDC to a metal surface if possible to ensure optimal heat dissipation, though this is not crucial.

The Solar Panel voltage thresholds are detailed on Page 3 of the BCDC1240 Instructions. The BCDC1240 control algorithm will maintain the maximum power point of the panel. In ideal conditions, 660W of solar panels will deliver 40 Amps from the BCDC1240. Technically, you can connect any number of input panels as long as the maximum panel voltage (open circuit) meets the input voltage range.

The conversion efficiency is in the range of 94%-96% being conservative. The efficiency is even better than this under certain conditions. At maximum solar wattage, the MPPT efficiency is greater than 94%.

Input and output voltage and current sensing ensures that, providing there is sufficient input power, the BCDC1240 will achieve the charging profile and current limit requirements even given varying sun intensity conditions. The charging profile is of course proprietary, but uses both current, voltage and time thresholds to ensure that over/under charging does not occur.

We have included a temperature sensor with our high end battery management system (BMS) product which features in-vehicle charging, dual battery isolation, MPPT solar regulation, 240 VAC charging all in the one package

http://redarc.com.au/products-and-services/bms1215-battery-management-system

We will certainly consider temperature sensing in future generations of the BCDC1240 product following further analysis and testing.

We are pleased to advise that our BCDC in-vehicle charging product was recently recognised in August 2011 by winning the Best in Design application at The Electronics News Future Awards. These awards recognise excellence in Australian and New Zealand electronics. The BCDC product range is exported to numerous countries including France, Canada, Middle East and New Zealand.

For those people unfamiliar with our company, Redarc is a power electronics designer and manufacturer based in Australia building products for the Australia's harsh road and outback conditions. Our expertise is designing electronics in compact packages and in the majority of cases without the need to incorporate a fan which can be noisy and prone to failure.

The BCDC1240 is a good example of this and we would welcome customer visits to our factory in Lonsdale to provide a tour and show the products being built and tested first hand.

Best regards

Anthony Kittel
Managing Director & CEO
REDARC Electronics Pty Ltd

This is unfortunately one of the more disappointing threads on ExplorOz from longterm respected posters!

Olcoolone, I don't always agree 100% with you, but you are 100% spot-on in this thread. I have used many electrical products over many years and Redarc would have to be one of the WORLD'S premier automotive manufacturers with unparralled backup service for their products. I currently have the Redarc BCDC1240 and it is a great product. I also have 2 Ctek chargers, Projecta charger and other various brand electrical components so can base my judgement on my personal experience as well as professional experience.

Peter (Battery Value), you normally offer good advise on this forum so its diappointing to see you denigrate a good product on such a flimsy basis. No product is perfect, they are built to a price point so every feature cannot be in a single product and still be price competitive. Sounds more like a response from someone who has sour grapes that they don't have the Redarc product lineup in their range. Why sell quality Australian products when you can import.... While import products may be cheaper, wait until you need backup support and see why they are cheaper.

Anthony, a dignified response but one you shouldn't have had to make.

Cheers

Captain