Notes from the Coal Face on fitting and managing battery and solar power
Notes from the Coal Face
on fitting and managing
battery and solar power
Here is some "coal face" thought to help the caravan, camper, campervan, motor home, Recreational Vehicle and 4WD user in Australia and New Zealand from Barry Davidson of Caboolture Caravan Repairs. Barry is a partner in the largest caravan repairers in Queensland and one of the biggest in Australia. His current business is also by far the largest installer [and repairer] of solar panels and hybrid battery systems in Queensland.
Barry started building the Phoenix range of vans in 1991 and sold the manufacturing section of that company three years ago. Phoenix was the first caravan builder in Australia, and one of the first in the world, to offer solar and hybrid battery installations as a standard fitting.
Barry's extensive experience in the caravan Industry includes more than 30 years in the caravan repair game, before that he was a police officer in the Traffic Accident Investigation Branch. His original trade was in the motor vehicle and engineering field. Barry is now in partnership with his son, Adrian, in Caboolture Caravan Repairs.
Your correspondent interviewed Barry on getting the best from batteries and solar power –
He says he is concerned that real "expert" opinion in the solar and battery field is in short supply and would benefit from more "coal face" experience when advising the caravan, camper, campervan, motor home, Recreational Vehicle and 4WD user.
Barry says - Caravan owners should take care when dealing with an alleged "expert" and be certain that what they are told will not be to their cost.
"The Solar/Battery industry has been developed with an unnecessary mystique", he says.
"This has led to a situation where the retail industry is still catching up with the need for real experience of the requirements, abilities and capabilities of the average caravanner. This is often compounded by the challenges inherent in fitting out most ‘over the counter' caravans.
"There appears to be very little understanding of the true power requirements of many of the items sold into and used by the caravan Industry under Australian conditions", Barry says.
"For instance my experience has shown that you can comfortably add up to 50 per cent to the stated amp/hour requirements given with most 12 volt refrigerators. Our temperature probes regularly record readings of in excess of 60 deg. C in the compressor area of many 12v fridges and the usual browsing habits of many caravanners add significantly to the daily power needs.
"Average runtime for a (a popular) style front opening fridge, for at least six months of the year, will be around 20 hours per day. We find that the most efficient type of fridge is the Vitrifrigo type which has an isolated fan cooled condenser.
"In many instances caravanners add a chest type fridge to their inventory list. They usually neglect to consider the power use of these additional units. Today television and general entertainment is one of the most power hungry additions to the 12 volt kit in most caravans. TV is usually accompanied by a DVD or video player and often the TV aerial is boosted.
"Many vans are now fitted with satellite receivers and the stated two hours use a day is very often five or six hours". "Other items not considered are things like vent fans, up to 3 amps/hour, CD players again up to 3 amps/hour. Domestic entertainment systems are another item that will blow any calculations of power use out of the water. "The average caravan owner often falls within the Baby Boomer generation, pretty much unable to go without all the comforts of home", Barry said.
"Solar panel installations are of little real use unless the owner is made completely aware of the real benefits and the real problems with such an installation. It is important that the caravan is fitted with a correctly balanced and high quality battery charger and it is also recommended that the vehicle be linked in to the charging system but the vehicle must be protected by a decent quality safety pack.
"Once again this comes down to the ability of the installer/seller to fully explain the potential options available and to not make the caravanner believe that Solar is the answer to all problems unless they are prepared to spend the necessary amount of money to set up a fully balanced and integrated system.
"Solar can be a wonderful adjunct to any caravan electrical system if the entire system is balanced and if common sense is used in selection of equipment.
"The most significant problem we encounter is where a sell/installer of solar apparatus places a dollar limit on the installation in order to sell it to the customer, not considering that the installation is far short of the actual requirements of the client. This only serves to create frustration and distrust with the client and creates another set of bad images for the caravan industry.
On the much debated subject of batteries Barry who has 30 years of hands on experience told GoSeeAustralia that:
"I have seen very few instances where Deep Cycle Batteries are ever the correct option for the average caravanner. This may seem to be a definitive comment and probably goes against the advice you will be given by the alleged battery ‘experts' but I have to work in the real world, not the world of theory and book learning".
"For instance cable sizes and temperature considerations are critical. Charging processes vary significantly with different battery types, the deep cycle type is one of the most difficult to charge within the caravan concept.
"Certainly they have a long cycle time, but they have a need for an extremely definitive charging regime and a very long recharge time. Most caravanners will not take the time to ensure that the battery is FULLY recharged before they take off. Hence the almost certainty of sulphation and then the inevitable problems with surface charge".
"Once the battery is showing symptoms of surface charging it is necessary to have the system broken down and the battery professionally charged, quickly. If this is not done correctly, the 1 ½ days of expected battery life quickly comes down to 1 ½ hours and we have a disgruntled caravanner.
Barry says the reasons not to use deep cycle batteries in caravans are:
- Far too subject to sulphation and, as a result, surface charge.
- Far too fragile in most instances. Continually drop cells when used on corrugated roads.
- Far too difficult to recharge fully and correctly in the average caravan situation. Solar alone cannot do it unless a massive and costly installation is fitted.
- Can never perform to the high expectations of uninformed RV users when used in the caravan situation.
- Too heavy relative to general performance capability.
- Not cost effective given that the average life span in caravan use would be under 12 months, often under six months.
Barry says marine type batteries [Trawler/Outboard Motor] work well in caravans because:
- Quick recharge capability cuts down significantly on sulphation problems.
- Can be brought back from a sulphation state using on-board charging facilities when the installation is correctly balanced.
- Vastly easier and more forgiving to recharge in the caravan environment. Charging systems do need to be as sophisticated and specific.
- Well insulated and vibration damped. Much more robust than deep cycle. Rarely drop cells through rough treatment.
- Power to weight ratio is more in keeping with the weight restrictions becoming more and more evident in the caravan industry. Most caravans are at peak load or more when loaded with basic items only.
- Very cost effective given that the average system we install can expect a life of in excess of four years. There is no possible hope of obtaining anything like that with an average deep cycle installation.
- User friendly. Even the most useless caravan owner can be set up with a simple regime to ensure full recharge and maintenance.
Barry says the old style caravanner doesn't exist and current caravanning Australia underestimates its power use:
- With a top opener chest type fridge be sure to allow for really hot weather. With a front opening fridge multiply by three.
- Lights. Average caravanner uses about 15 to 20 amps/day. The Baby Boomers can't live with only two lights and they don't go to bed at 8pm.
- Television and entertainment. Treble your estimate for the average user. Don't believe the stated power consumption of most entertainment appliances, it is usually vastly understated.
- Radio/CD player. Most caravanners will play CD's all day when they are camped up and the average car type player uses up to 3 amps/hour under our tests. We allow up to 15 amps a day average and this can be a lot higher.
- Other considerations must include:  range hood av. 6 amps/day.  pump/s, we allow 7 amps/day. Don't forget all sorts of small battery chargers, telephone, video, camera, lap tops, detectors etc. etc.
- Remember that only very rarely can van solar panel installations be set up facing the sun. Almost all vans are fitted with flat panel roof mount set ups. We allow an average of 5 hours a day peak charge Australia wide.
"When discussing installations it is essential that advice is given to ensure switching of the system both sides of the regulator. The average caravanner is sure to cross polarize their battery at some time or create a flash one way or the other. Even though solar panels are supposed to be dioded we have had a number of customers who have managed to short them out and they also seem to have a propensity for blowing regulators the same way. Make sure that a re-settable circuit breaker is fitted in line as well", Barry suggests.
"In general, and I know that finances come into play here, I find that any half serious caravanner requires at least a 120 to 160 watt solar panel installation and at least two marine 85 a/h batteries. This should be coupled with a good quality 20 to 30 amp battery charger in order to make the best use of the ability to free camp three or four days a week.
"The usual installation for the serious caravan park skipper would be 3 or 4 x 120 watt solar panels and 3 or 4 batteries with a 40 amp high quality battery charger. "Each of these systems would be augmented by a comprehensive vehicle charging installation and would have the ability to be backed up by a generator when necessary".
Barry says his company has noticed that the new Kyocera dark blue panels are performing significantly better than the stated specs. "As a result we have had to increase the rating of the usual circuit breaker installation. We have been getting significantly better than 11 amps output from some of them in average sun conditions, not bad for a 125 watt rating".
"Another significant problem that is rarely mentioned by the ‘experts' is line pressure switching when the input amperage from the solar panels equals the output from the battery charger, switching both of them out of the circuit. The caravanner does not realise that both the regulator and the battery charger thinks that the battery is charged and they both go into float mode and cease charging, the immediate result is a flat battery at midnight", he said.
"Solar panels are of little use when the vehicle is moving. Our tests have shown that little or no charge is available to the battery from the solar panel/s when the vehicle is moving, particularly in wooded areas.
"The caravanners best friend relative the questions of battery maintenance etc. is a hydrometer. In general the instruments available to the caravanner, volt meter, and amp meter, etc. will not give an accurate reading of the state of the battery. A hydrometer will, hence the preference for wet cell type batteries" Barry Davidson said.
For more information
contact: Garth Morrison
Editor GoSeeAustralia and GoSeeNewZealand Directory
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