Let There Be Light

Further to Anthony's comments.
I would suggest fitting the 30 amp regulator as well.
Saves upgrading later if you go to 3 batts x 3 panels.
Everyone I know with a 190 ltr fridge that started with a 2 x 2 set up has eventually gone to 3 panels, 3 batteries.
In fact I believe that Steve is not advising correctly when he says that 2 panel set up is ok for a 190 ltr fridge.

Regards
Turist

Totally agree with Turist's comments. We originally took delivery with 3 Panels and 3 Batteries. We spent 3 months this year travelling through Centre, NT and the Gulf Country in Qld. Hot weather for most of the trip (at least that part of the trip North of the Victorian border!). During the trip, had problems maintaing suitable power levels in batteries if we were camped in the one place for more than a few days. Once on the move, we got power levels up agin via the Anderson Plug. BT checked out the system and found nothing wrong. In order to be more safe than sorry, I had a 4th panel fitted. Have not had a problem since!

Hi Anthony, Thanks for that advice. According to Paul our batteries are being placed under the L shaped lounge I guess two under the long seat wall side. I assumed a third could go under the shorter seat backing onto the ensuite. Where are your batteries positioned in your 18? Apart from the lights, the electronic HWS ignition, the flo jet pump possibly a small TV/or single CD player (its not what we play it on.... its what we play) on a single plug in inverter and maybe a 12v hair dryer and of course the 140ltr fridge without other mod cons what else would demand power that I've overlooked? I thought the wine chiller might be a bit of a drag!!!! Turist, We are only going for a 140litre Danfoss fridge not the 190lt but we are getting a 30amp regulator. Steve was actually advising us to go for the 190lt and three batts & panels. Initially we wanted to get a three way fridge but Steve talked us out of this in favour of the compressor driven job due to drag at stops. Collyn recommended on the forum some time ago that he would suggest a 140lt comp driven over the 3 way for a larger caravan and if a bigger fridge was required he said from memory that a 190ltr would need 2 panels dedicated to it . I will study the book closely and do the sums. Thankyou both Regards, Helen Helen

Motley, Doesn't this come down to how many appliances/lights and the amount of power they draw down on the batteries. Are the Kyocera panels the only choice or are there other brands that suffice. Cheers, Helen

A useful list for power draws & info on the basic outline of power systems is on the Bainbridge site. Have a look at www.baintech.com.au then enter & go to the link on the right 'How long will my batteries last? Griff

Helen, There was much discussion on this problem at Cania Gorge. We had kept our use of appliances to an absolute minimum. I know that's a subjective thing but we had been very careful. One variable that emerged at the time was that the efficiency of Solar Panels ie. Output (I think) decreases as ambient temperature increases. I'm not saying this was the total cause of the problem, but we did experience very sunny, hot days for extended periods. Adding the 4th panel effectively increased our Solar output by 33%. As I said, we haven't had a problem since and we have had occasions when we have been driving, with Anderson Plug connected where we actually registered an overvoltage alarm on the ProStar. We certainly didn't get that with three panels. We do not need to use Anderson Plug any more (or we haven't on the last 2 trips) The other variable of course was that the hot conditions did require a fairly constant replenishment of bottled fluids in the fridge. It's amazing how many cold stubbies you actually require when the days are hot and dusty!

G'day Helen and John, Nuffin like a good flow of info .... must seem like its raining down on you at the moment ! [smile] My battery box is under the "L" shaped lounge in my BT18. In the section near the ensuite wall, it has 3 batteries in a single box. Maybe the newer batts are bigger in dimension so might only fit two ? Fitting two batteries in one spot and one in another is not worlds best practice as they have to be connected with cables between them obviously. It gives two areas that has to be vented and is electrically untidy. If it has to be done it has to be done. Further to the solar equation .... you are right in saying that it comes down to how many appliances you have and the power drawn. That is half the story the other half is you have to put it back and several things affect this ability and create need for more panels even without using more power. The first is orientation ideally the panels should face north and be angled towards the sun. This angle varies depending on the distance away from the equator. This is not practical when mounting panels on a caravan and flat is the only way to go. To compensate for this you usually add at 20 % more panel than is necessary .... to bring output up to level of an angled, orientated panel. The other reason for adding more solar panels is called solar autonomy. It basically means being able to be free from 240 power as long as possible as conditions become unfavourable for solar. For example, Heat, overcast days, rain or even the shade of a tree over the panels for some of the day. Even down to being in Southern Australia in winter (less solar hours). The more panels the more autonomy. I have 4 x 120w panels on my BT , 3 batts and a 200w inverter. My power needs by most BT standards is low but I have four panels giving great autonomy and room for electrical expansion in the future. As an example I can take about 6 days of rain before I have to move (by third day I'm leaving anyway) and can tolerate a fair shade influence over the panels during the day. Doesnt matter how hot the panels get, 480 watt has me covered. I'm not saying fit 4 panels but I'm saying make the system expandable/upgradable and you have this already. Fitting the 30A regulator, having bat box for 3 bats and affixing the first two panels on top of BT in such a way as to allow more to be fitted if needed is smart BT "build" ! This gives the least cost and hassle to expand later if warranted. Hope we've not bombarding you too much ..... [smile] Anthony Explore this Great Land ...Do it Easy ...Tow a Bushtracker

Hey Anthony, Again good advice - thankyou - and we really appreciate the imput and the effort in explaining things. We have not had any experience with solar dependency with a vechicle/caravan setup before, so it would be foolish to ignore the consensus of opinion on such an important factor regarding 'solar autonomy'. This is where we find the forum really helpfull and the advice given so willingly based on boggers experience invaluable. Never too much information... we can handle it A further question though. Is the ProStar Motley refers too the 30amp digital multimeter regulator or something different? If different is it another safety feature ...bit confused here and the Anderson Plug is it in addition to the standard power connection to the BT or does it replace it. Guess your busy being Santa tonight Anthony..... have fun..... ho ho ho Cheers, Helen & John

Helen & John, The Pro_Star is the Power Regulator for taking the output from the Solar Panels and charging the batteries. It continually monitors the state of the batteries and manages the charging process from the Solar Panels. The charging process varies with the amount of residual charge in the batteries and the ProStar looks after all this. It has a display which alternates between Battery Voltage, Solar Amps coming in and Current Draw. As Anthony said once before, it becomes a bit of a "shrine" for BT owners! Have a look here - http://www.morningstarcorp.com/products/ProStar/index.shtml The Anderson Plug is a two wire/two way connection from the vehicle batteries to the Van batteries. It's not necessary but I think a good option. If you are driving on an overcast day, then the van batteries are still being charged via the Anderson cable from the car batteries. Alternatively, if you are stationary for a while and you are running a fridge in your vehicle, then the vehicle's auxiliary battery can be charged by excess power form the Solar Panels (assuming that the van batteries are topped up). If you wanted this option, you weould need to let BT know and they will cable it, including a length of cable to connect van to vehicle. Then you need to go to a towing place - Hardings or Pirahana in Melb for instance and they will install the other part which is basically a cable from auxiliary battery to a plug (Anderson) on the Tow Bar. Hope this helps. Off to put the turkey on now (is it too early for the first glass of bubbly???) Happy Christmas

Thank you very much Motley. I asked the same question of Collyn a while back and he didn't give me an answer. Thanks for the info Macka

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Hi Motley, How was the turkey ? And you never need approval for a pre brekky bubbly on Christmas Day, New Years Eve/Day, any Sunday etc. etc.... its a given!! Thanks for the info and advice, much appreciated. We're getting it sorted. All the best for the New Year and a great 2004 Cheers, Helen & John

Griff Just sorting out the finishing touches on our lighting and would like the info on where you got your external lights for your van and are the 20w xelogen globes able to go into the standard fittings in the BT Rod

Rod Griff is off travellin'. All of his lights came from http://www.12voltshop.com.au/. I am installing the same interior and exterior lights too. Like them very much when we visited Griff nad family. Cheers, tgintl/jay

Motley Pete Output from most solar modules (except Uni-Solar) decreases by 0.5% per degree C above an ambient temperature of 5 degrees C (not 25 degrees C as commonly believed). Thus loss at 35 degrees C is 15%. In practice further constraints keep max output of a typical 80-watt module is about 58 watts, and of a 120 watt panel is about 90 watts (in 12 or 24 volt system).This, coupled with fridges drawing about 5% more power for every degree C rise in ambient temperature is probably responsible for a lot of the reported problems at Cania. But too light cabling doesn't help either A 190 litre fridge will need at least thrre modules (personally I'd go for four). The sums are simple to work out. If essential economise on batteries - never on modules. If you can't make it, it's not there to save! Macka - sorry if I omitted to reply - have certainly responded to your questions in the past. Maybe you wrote when I was on holiday. Collyn Rivers