Anyone know how long my two 83am deep cycle batteries will let me free camp?  I understand the gas stove and fridge and that the house batteries will run the lights. I was told about two maybe three nights. (laptop lasts 2 hrs)
In other words how do motorhomers free camp for days on end without flattenening house batteries.  Don't I need power eventually to recharge (c/van pk)?
any thoughts gratefully received....
cheers

Hello.  Maybe look into a bit of Solar.  Great once you have it fitted.
Barb.

You need to know exactly what you are going to use by wattage or amps.
For example, my TV is rated at 5 Amps, that means it uses 5 Amps per hour, most water pumps fitted to caravans/motorhomes are also 5 amps. Our average daily power consumption is 17 amps.
So look at everything you will using and work out your daily needs.

As Barb said have a look at solar.
We have 2 x 80W panels and 2 x 100Amp batteries fitted and the longest we have stayed out free is 18 nights and the only reason we have gone into a Cp is to have a long shower and do laundry.

I would check the computer if it's eating up the house battery in around 2 hours ,they drag bugger all amps. If everything else is on gas then it's only lights and maybe a radio so the total you have is about 80 amps (limiting it to a 50% discharge ) so you should get about a week + out of the battery bank without a recharge from the mains supply or solar panel

-------------------------------------------------------------------------------- Hello Sue no you cannot plug your 240 applainces into your batterey bank unless you have an inverter,to use them you should be in a CP, with just two 80Amp hour betterey you would flatten them pretty quickly, the greatest users of power is heating and cooling, cooking and airconditiner, I recommend you fit solar panels to the roof I am surprised that you have got this far with out a loss of power allready As with all electrical stuff the cooler it is the better it works, so make sure there is a gap underneath the solar panel for air flow when mounting them on the roof I have four 80 watt panels to fit to the roof of the bus, and each panel puts out 5 amps when the sun is shining clear and uninterrupted on them, multiply amps by volts and you have 60 watts x2 panels, In general it will produce 70% of its rated power as it is not fixed to face north For capacity, or amount of power on hand,, multiply both volts and amp hours to get the wattage, =12v X100 amp=1200 watts per hour battery, So with your setup you have available 12v x 85amp x two =2040w Dont take out more than 20% from the batteries, before charging them with a solar controller this is all automatic if in a CP you can buy a 12v charger from any hardware place and plug it into the parks power supply which is 240volts, get one which will be rated above 7 amps They have warning lights fitted and are really easy to use If you have a TV which needs 75 watts, (you can see from the label on the back its power consumption, a radio that needs 10 watts, plus a speaker system as an extra that needs 30w, a computer that needs 30w, and a fridge that needs 60w then you add them all up for a total wattage of what you need and we have a total of them all =205 watts per hour Howerver the sun doesnt always shine bright and clear, if a week went by with grey clouds, you would be down a little on power Another panel, or the use of a generator will be required, Or you can reduce consumption,--------------- we are all different power users you work it out from here. if still in the dark let me know and I can turn on the light; at least try again

Hi Sue
not sure how much or what type of info you are after.
i have only free camped for the occasional night and use the 'in house battery' for lights only, as these are the only items hooked up to my 12v system.(apart from 3 way fridge which i have been told will flatten the battery quick smart).
If staying out longer you would need solar panels to recharge the in house battery or if you wish to have 240 v power you will need a generator. Think this simple answer is basically correct, the more knowledgeable will correct me no doubt.

If you turn off the power at the c/van park you are now in, you will see what is connected to your house battery.



Johnw


-- Edited by jandas fun on Friday 29th of May 2009 09:31:54 AM

Collyn Rivers, a retired engineer I understand, has several books on matters RV including solar which are relatively easy reading.

His opinions are generally well respected on most RV fora.

http://www.caravanandmotorhomebooks.com/

The percentage of usable power is calculated from the power rating stamped on the battery. eg with a 100AH battery you can use 20AH if you only have 20% to safely use.

There are different types of batteries so the 20% is for the cranking style wet cell batteries (the ones used in a car to start the engine) Not really the ones to have for house batteries.

If you have AGM's or GELS or similar then you can use about 50% of their rated power.

There are other batteries that give much greater power availability but are not widely used even though they are easier to use and give more power at a higher voltage for a longer time.

The rated available power is to stop the battery being depleted past a point where it can be safely bought back to 100% regularly. The more you take it past its rated available power level the shorter its life expectancy.

Most of the older style batteries should be returned to 100% withing 24 hours or there will be a loss of performance. In the RV lifestyle this is not possible so we accept a shorted life.

To get an AGM or similar battery to full takes days and many people assume that when the solar goes off boost it is full when it is really about 80 to 85% full. For a battery to be full there should be no charge being out in from the charging source.
If you in fact have deep cycle batteries you should be able to use about 50% so 40AH if your batteries are new and fully charged.

As batteries age their capacity drops and therefore the 50% value drops as well so you progressively get less available power. This is why you often hear people say "my batteries have been working well for 2 years or so but now seem to be failing" this is because the available power has been deceasing until the available power is not enough to deliver the AH's required. If you charge your batteries to 80% then you have 50% of that 80%. eg 80AH = full so 80% =64AH therefore you have 32AH available.

I hope this is the info you were seeking

Regards
Brian

Sue I am like you, this information got lost on me....somewhere on the first paragraph, I'm good with electronic things, but doing the battery, solar thing has lost me.

I am so lucky our van came with solar panels, in house batteries, even has 12V plugs inside and out. We are set up for free camping, but I don't think we will be using it for longer than 2-3 days at a time. Small town caravan parks and rent assistance sound good for the most part of our long term camping.

Good luck on getting your tank fixed, what a pain.

Suenami hasn't been on since 2009. Its amazing that these old threads surface isn't it.