Power, When Off Grid.

[ProfJohnL]

Some batteries do have a vent tube or a spigot for a vet tube. That should be sufficient to take the fumes away, but I'm not certain that ALL leisure batteries have that facility, so drop holes in the battery compartment would probably be sufficient.

I forgot to mention that the batteries should be firmly fixed so they won't move around when the caravan is towed. A loose battery can do a lot of damage.

 

[ProfJohnL]

Hello Whiz,

24V in a caravan - Definately not. The clue in my correspondence is the word "parallel" What you have described is connection in "Series"

HGV's tend to use 24V but all their equipment is specified for 24V.

 

[Lonesome-Whizkid]

Ok thanks, Only reason I asked, I was looking on ebay at inverters and some were saying it was a 24 volt supply to operate. But now I know that caravans are solely 12 volt or 230 volt mains.

 

[colin-yorkshire]

I was thinking twin 110/120 AH and yes I understand they need to be a matched pair but that would be ok as I`m starting from scratch and have a good battery supplier.

you could get two normal battery boxes "with flaps" from a breaker and put one either side running the cables under the floor, thats the beauty of restoration from scratch a blank piece of paper to work from.

 

[manaboutthehouse]

Ok thanks, Only reason I asked, I was looking on ebay at inverters and some were saying it was a 24 volt supply to operate. But now I know that caravans are solely 12 volt or 230 volt mains.

They tend to be for lorry use as they are popular for powering tvs when staying out

 

[manaboutthehouse]

you could get two normal battery boxes "with flaps" from a breaker and put one either side running the cables under the floor, thats the beauty of restoration from scratch a blank piece of paper to work from.

Ok Thanks Colin not seen those yet any chance of a picture or link?

 

[colin-yorkshire]

no problem one like this or similar http://www.ebay.co.uk/itm/battery-box-side-locker-caravan-motorhome-camper-/261465892103

 

[Lonesome-Whizkid]

This caravanning hobby is a real eye opener into the world of mobility and having a home from home parked almost anywhere you like. Totally awesome. Gone back to reading my Haynes manual for caravanning. I'll be back with more questions to pick your brains lol.

 

[Lonesome-Whizkid]

I've got my eye on a 12v travel kettle and its 170watts and I just wondered if my cars cigarette lighter socket has the ability to cope with 170watts running through it, If it doesn't is it just a matter of upgrading the fuse in the fuse box or is that a no go area?

 

[WoodlandsCamper]

170 watts at 12v is about 14 amps. I believe car 12v sockets are only rated at 10 amps, so the answer is no - don't do it.

 

[Lonesome-Whizkid]

What about a 12v 120watt element that you stick in a cup to heat it up?

 

[Lonesome-Whizkid]

Here is the add I was looking at, I don't understand why there advertising it to use in the car if the wattage is far too high?

http://www.ebay.co.uk/itm/12V-170W-1L-Car-Van-Travel-Electric-Water-Kettle-Jug-RD-/120643836308?pt=UK_TravelTickets_Accessories_RL&hash=item1c16eed994

 

[colin-yorkshire]

hi LW, theres a formula for working it out the old brains a bit dull but I think it is watts divided by volts = amps. or something like that so a 120watt element divided by 12v = 10amps

EDIT. scratch that!!! can't read either is 170 watt not 120,

 

[Lonesome-Whizkid]

I just checked the power outlet in the car and it says 12v - 120w on the cover so can anyone recommend a good 12v kettle for making on the spot tea and coffee?

 

[Lonesome-Whizkid]

I'm still really confused why there selling 170watt 12 volt kettles on ebay for the car when you've not to go over 120watt, Not unless small cars have small amper allowances and large 4x4's and jeeps have a larger allowance? Then I'd understand? :huh:

 

[ProfJohnL]

Hi LW,
Its a case of buyer beware, neither the car or the kettle manufacturer can realistically know that you would be putting these two products together, so its up to the purchaser to ensure that both the car and the kettle will work together satisfactorily. As far as the car manufacturer is concerned he is only supplying a cigarette lighter, so they may only need to have it rated to 10A. Some manufactures may fit power outlets with a higher rating, but you need to check the specifications.

 

[Gafferbill]

I just checked the power outlet in the car and it says 12v - 120w on the cover so can anyone recommend a good 12v kettle for making on the spot tea and coffee?

......my tip is not to bother with a 12 volt kettle. They take forever to boil even a cupful of water and I have not found one that is durable. They will leak or give electrical problems sooner rather than later.

Much better to use a portable gas stove for boiling water.......there are many types available.
You do have to pay attention to safety as regards a naked flame and potentially scalding hot water.

 

[Lonesome-Whizkid]

Yeah,

I think the gas stove is a better idea, I'll get one out of go outdoors and a whistling kettle aswell.



lol :woohoo:

 

[Lonesome-Whizkid]

But I'd like to ask, ProfJohn, Can I upgrade the fuse to a 15amp in the car fuse box or would that do damage to the cars electrics if I were to plug in a 120 watt or even a 170 watt kettle?

 

[ProfJohnL]

Hello LW

DO NOT UPRATE FUSES!!!!!

Fuse are there for a purpose to protect the wiring and connectors against too much current being drawn through a circuit. If you draw too much current the cable or connectors may not be able to handle it and they will heat up. They can melt and then cause a short circuit, which even with 12V can start a fire.

 

[Lonesome-Whizkid]

I had a feeling that would be the case. I seen a cigarette lighter charger for the mobile phone today. It's funny, when you take up a new hobby the things that catch your eye that you'd probably walk past any other time and not even notice. Tell me if I'm correct on this, Could I sit in a grass park all day long with a picnic and laptop and mobile internet connection and a solar panel connected to the power outlet of the laptop and easily be online all day long if its nice and sunny or am I hoping for too much?

 

[TD42]

not that simple im afraid :dry: a lap top requires a regulated smooth supply usually about 19v@ 3amp aprox. in order to avoid damage to the laptop.so in your scenario you would need a solar panel of around 40watt connected to a 12 v battery then a regulated transformer such as http://www.ebay.co.uk/itm/like/171233193894?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0&ff12=67&ff13=80&ff14=108
the solar panel would keep the battery topped up & the transformer would supply the correct voltage to the laptop if the weather supplied sufficient light for the solar panel to work effectivly

 

[Lonesome-Whizkid]

If the car cigarette lighter outlet is maxed at 120watts does that mean that if you have a 120watt inverter plugged in that that's what it will draw from the car or does that mean it gives out a max of 120 watts? and only uses less from the cars power to operate it?

 

[ProfJohnL]

Hello LWK

It means the cigarette lighter socket is rated to give a maximum of 120W (= 10A @ 12V) for a short while. If you try to pull 10A for long, the socket is likely to start to melt.

The rating of the inverter is its maximum power capability when working flat out. if you were to plug a 100W light bulb into your 120W inverter, it will only try to pull about 100W from the 12V socket.

In practice inverters are not 100% efficient and need a few Watts of power for themselves, so with a 100W (230V @ 0.42A) bulb, the inverter will probably pull nearer 110W (12V @ 9.2A) from the 12V supply.

 

[Lonesome-Whizkid]

Thanks John.