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Post Info TOPIC: Battery and solar sizing for free camping ! Ideas !
Jaahn


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Battery and solar sizing for free camping ! Ideas !
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Hi smile

Hi I thought that I might answer some common question about batteries that members might ask or want to ask but feel it is too silly.  Nothing is too silly by the way. This is aimed at free camping use for some time and is giving ideas not exact answers.

The battery in your van or MH works like the mobile phone battery in your pocket. Every day you plug it in till it is fully charged. If you do not charge it, it will not work. Phones are designed with a good battery management system (BMS) and a good easy to read battery meter and they work very well.  So that is also what you need with your house batteries. Charge them regularly to full, every day if possible, get a good battery management system (charger with stages) and a good easy to read battery meter.  

How much battery do you need. Well like the mobile, that depends on your use and how you can charge it. Basically it needs to be big enough to last you till the next charge. Some people that may be once a day, some might last two days or more. BUT the important thing is that next charge. So after you estimate your expected usage, enough battery to get to the next charge is the correct answer.

 If you rely on solar then you must decide what period of poor weather to get through. If you can go one day without charge then you need two days of battery power. OR an alternative means of charging for longer. With plenty of solar you should be able to charge most days and then use the excess power during the day also. If your solar struggles to charge by the afternoon then you do need more and that applies no matter what size battery you have.

There needs to be a practical balance between the solar and the batteries for continued use. If the batteries are too big they take too long to recharge. If the solar is too big the extra power is wasted after the battery is charged early. People often say 200W solar for every 100AHr of battery is a good balance.  So have 400W to charge 200AHr etc. Often vans have never enough battery and the solar is even less. More solar does not harm anything though and is very useful.

The other consideration is the problem of not enough sun. You need a backup charger. The best one is the alternator on your motor. This can provide good charging while you drive and can also do a top up in poor weather. Or you can choose a generator but unless you have a good high amp charger for that it will take forever.     

There are plenty of camping and battery sites and threads here, that will give you a table of average use for small users, medium or heavy use. In my opinion the most important item might be the fridge. A gas fridge uses no electricity on gas. It uses lots of electricity if you switch it off gas so do not generally do that. If you have a compressor fridge you will be a medium user at the least as it goes 24/7.  

I trust this may help some people for a direction. Look in the Solar sub forum, up the top, also for more discussion. Solar Power The place to discuss all things solar

Cheers Jaahn



-- Edited by Jaahn on Tuesday 28th of July 2020 01:52:40 PM

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markf


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Good stuff Jaahn. The most important question is "How much battery do you need ?". The answer to that question is the root of the whole equation.

When it comes to solar power production I'd suggest sizing your system with winter sun in mind. If you can be charged fully by mid to late afternoon in winter then summer will be a breeze.

There are a lot of people here who are very well qualified to help you design a good system that suits your usage. A lot of the more qualified ones have gained their knowledge by bitter (and expensive) experience.

Just ask and be prepared to get a good quizzing on your expectations and usage and when asking questions please have an idea of what you want to accomplish.



-- Edited by markf on Wednesday 29th of July 2020 11:11:36 AM

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Warren-Pat_01


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Hi Jaahn,
This is well written, good advice - perhaps Cindy could make it a "STICKY" post??

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If you don't get it done today, there's always tomorrow!

2019 Isuzu D-Max dual cab, canopy, Fulcrum suspension; 2011 17' Jayco Discovery poptop Outback
Bicyclecamper


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Yeah, I run a 105 ah AGM, and use about 8amps per night, so only need my portable 80 watt panel, for a couple of hours to charge, but as we only camp in the cooler months, sometimes it can be up to 3 days with out a charge, but that is the most usually. So 24 amps over 3 days, I don't worry about not getting a charge. My Jaycar panel is very efficient, and if it is not raining, I will put it out for what ever charge I can get in cloudy weather, usually around 2 amps an hour, instead of up to 4.5 amps in sunny conditions. Am very happy with what I have to do the job.

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JohnR


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We have 2013 Jayco Sterling Outback that has the original battery. (7yrs)

We have 2 X 150 solar panels that keep things charged.

We have not let the battery go below 12.5 and if we are free camping we boost the charging with our Honda Gennie.

Battery is utilzed for lights/slide out/tv/satellite and numerous pretty lights that shine in the dark.

If it gave up the ghost tomorrow I would have no qualms.

 

John R

 

 



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iana


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Sort of depends on what you call free camping (I prefer the word "low cost camping") ?, if you mean a camped a single night between powered caravan parks, with a 3 way fridge, no TV because you are out side around the fire with your mates. Then a single battery and panel would do just fine. But try 7 nights off the grid, a compressor fridge, a TV going and the diesel heater working for a while, and its a different story, especially if its winter time. We also have a whole host of USB devices that require charging, on the seventh day, you are in the dark.
If you are travelling during the summer months, that is good, the sun is high, and the days are long. But during the winter, the sun is low on the horizon, and the days are short. You need to maximize the sun harvest to get by. A means of tilting the panels should be on the agenda here.



-- Edited by iana on Thursday 30th of July 2020 05:40:39 PM

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Peter_n_Margaret


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JohnR wrote:

We have not let the battery go below 12.5 and if we are free camping we boost the charging with our Honda Gennie. 

 12.5V is probably 75% full. That is a total waste of a generator.

Cheers,

Peter



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OKA196, 4x4 'C' Class, DIY, self contained motorhome. 960W of solar, 400Ah of AGMs, 310L water, 280L fuel. https://www.oka4wd.com/forum/members-vehicles-public/569-oka196-xt-motorhome
 

 
Aus-Kiwi


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If he didnt run the geni ?The battery voltage would have been way lower . Why is it so many are against a good generator? Some carry on against them like vegans about food ! Its more about space,weight and room
.

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Peter_n_Margaret


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If he ran it when the batteries were at 25% capacity, that might make sense (and he might never need to do that), but running it at 75% makes no sense.
And whether you like it or not many of us find generators serious noise and air polluters that in many cases are unjustified.
Cheers,
Peter

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OKA196, 4x4 'C' Class, DIY, self contained motorhome. 960W of solar, 400Ah of AGMs, 310L water, 280L fuel. https://www.oka4wd.com/forum/members-vehicles-public/569-oka196-xt-motorhome
 

 
JohnR


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The Van has been parked up since March at the base camp.

The lowest reading has been 12.5 being an overcast day.

The best has been 14.1 to 14.2 relying on the 2 solar panels on nice winters day.

It is a bit like a glass half full or glass half empty. Read it how you want.

What I was trying to point out that you can get away with a single battery with support from a gennie.

The battery or van will be 7yrs old come December.

We have been on the road for 7 years have 155000 klms on van.

Last year our accommodation costs were less than $10- per night this is based on low cost camping and house/farm sitting.

 

Say what you like the Honda 20i is part of the traveling furniture and has reserved spot in the back of the cruiser.

 

****Off the subject but talking about batteries.

I have purchased the next doors 1998 Mitisubishi Magna as a run around in lieu of the Cruiser.

It has been stationery for 8yrs. The battery left on the ground.

I charged the battery overnight.

The Car started on the second turnover and managed to get me to the nearest garage.

There you go////////////////////////////////////////////

 

JohnR

 

 



-- Edited by JohnR on Friday 31st of July 2020 09:09:10 PM

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Aus-Kiwi


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Some find starting your main motor to charge batteries to to be offensive!! Theres better and rubbish throw away generators out there ! More so in the past hopefully . Some put them all in the bad offensive basket !! Like a 6.5 diesel ( in my case) running to charge is environmental friendly . Over 2 cyl diesel

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Peter_n_Margaret


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Modern vehicles have strict emission and noise regulations that are legally enforced. And if you are going for a drive anyway, there is virtually no extra emission or noise.
It costs very little to set up to use the facility, so why not have it available?
There are no such standards for portable generators and they are typically extremely poor.
Cheers,
Peter

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OKA196, 4x4 'C' Class, DIY, self contained motorhome. 960W of solar, 400Ah of AGMs, 310L water, 280L fuel. https://www.oka4wd.com/forum/members-vehicles-public/569-oka196-xt-motorhome
 

 
Whenarewethere


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Two years we were in Purnululu NP, no generators allowed, in the morning people started their diesel engines to charge batteries. There was no wind & one could cut the air with a knife. The next night we slept in our car in a carpark, it's not allowed, but the fumes were unbearable.



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Plain Truth


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Hi Jonathan,you must have camped in the Kurrajong area they have no generators there.

The Walardi camp area has a non-generator area and a generator area.



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carpaidiem


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I recently put a 240ah Lifpo4 Lithium setup in our van, also have solar. 12 volt TV, compressor two door 175ltr fridge, Truma 2400 gas heating all the bells and whistles.

went on line to do calculation on how long we could "free camp" result indefinitely !! fantastic. only problem is WATER generally lasts about 3 days. after which time find a tap, well or caravan park. So now I am one of these idiots blowing his bags about how much power I have LOL. Oh well at least i shouldn't be left in the dark.

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Whenarewethere


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We stayed 1 night in Walardi as it was booked out, end of May, & paid for another 2 nights at Kurrajong, but stayed 1 & used a car park the last night. The exhaust fumes were out of hand & we are used to Sydney pollution!



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Whenarewethere


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carpaidiem wrote:

I recently put a 240ah Lifpo4 Lithium setup in our van, also have solar. 12 volt TV, compressor two door 175ltr fridge, Truma 2400 gas heating all the bells and whistles.

went on line to do calculation on how long we could "free camp" result indefinitely !! fantastic. only problem is WATER generally lasts about 3 days. after which time find a tap, well or caravan park. So now I am one of these idiots blowing his bags about how much power I have LOL. Oh well at least i shouldn't be left in the dark.

 Compressor fridges are very efficient these days. Our tiny Waeco, which had a poor surface to volume ratio, uses about 12 - 15Ah per 24 hours. We have 4 X 26Ah gel batteries hidden around the car. For lighting we use Olight torches which are extremely economical & mostly charge them when driving.



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Aus-Kiwi


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Peter_n_Margaret wrote:

Modern vehicles have strict emission and noise regulations that are legally enforced. And if you are going for a drive anyway, there is virtually no extra emission or noise.
It costs very little to set up to use the facility, so why not have it available?
There are no such standards for portable generators and they are typically extremely poor.
Cheers,
Peter

 No i am mainly free camped . EGR idle or little load doesnt help.  The EPA, EGR  on latest diesels dont do them too good . But the greenies down Vic seem to think diesel is ok . Truck engines as in motorhome is still much noisier than my little inclosed well muffled geni ! But I could go months before starting it !! Its just there if required!!  Last year down south / WA we had 3 weeks rain ! omg !!  

 

 



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Ziggy99


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"Modern vehicles have strict emission and noise regulations that are legally enforced. " When did DPFs become mandatory and what proportion of vehicles out there have them? How do you know if the diesel idling next to you has one? Because ingesting diesel particulates is a health hazard, apart from an idling vehicle destroying the amenity of your camp. The only reason for it is laziness. Don't get me started on EGR tampering. Legal enforcement? Not in the planet I live on.

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Whenarewethere


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I don't see any enforcement of extremely noisy vehicles around Manly, even with police cars next to them.

When I picked up my car from a service last year my mechanic hadn't done the pink slip. I won't say how he tested the brakes without being in the car, but I did ask some questions.

He said the brake test is based on the oldest road registered car in NSW. If that car is in road worthy condition it is unfair that the test is tougher. That car has leather brakes.

I also asked him aren't you checking the exhaust. He said as long as no smoke is coming out then it's ok.

My pink slip passed with flying colours.



-- Edited by Whenarewethere on Monday 10th of August 2020 09:12:56 AM

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