Ideal electrical set up???

[ghost123uk]

Ah no (as Frankie Howard used to say) in a normal LPG system the liquid gas is turned into a gas by the vapouriser and then fed to the engine so we don't have to worry about that.

As this is a generator we also don't have to worry about an "accelerator" = just set the butterfly in the carb for the air and adjust the gas flow with a simple tap. I tried it as "proof of concept" with a 4 stroke lawn mower engine by attaching a rubber hose to a hand held (B&Q Brand) gas blow torch (not lit of course) and fixing the hose to squirt the gas into the carb and adjusting the flow of gas with the knob on the blowtorch = worked fine.

A person (such as me ) with a bit of electronics knowledge could easily rig up an electronic "governor" to keep the RPM at the desired value for the generator set up. (but that is for the future - for now it is an exercise in fuel systems )

[trentjim]

well the variable you didnt define is the energy demand of the loaded engine driving the generator...

gas gets delivered as a liquid then vapourised because it is the best way of quickly moving the energy from a-b, as a vapour its volume makes moving it around difficult - especially at the very low pressures of mains gas.
a domestic gas meter is set to deliver gas at a rate no faster than 6 cubic metres an hour
but you will need pipework to get to your engine
with a 20m straight run of 15mm copper pipe from the meter you will be able to deliver 0.95 cubic metres of gas per hour to the engine.
natural gas has an energy density of 10.68 kwh per cubic metre of gas
therefore the gas pipe will deliver 10.14kw per hour to the engine.
what does this mean, well a litre of petrol contains 9.7 kwh, so unless your engine used less than 1.05 liters of petrol per hour you are going to need to store and pressurise the gas.

But "NO!" you cry, "your dodgy figures for the Sprinter van suggested that an engine driving an alternator would be chomping through 3 litres per hour or so - Dispair... it cannot be done"

fear not - if we can get the engine close enough to the house we might just be in luck..

with 2m of 15mm copper pipe and 3X90 degree elbows, delivery at the engine would be 2.9m2 per hour, this would be an equivalent fuel supply to 3.18 liters per hour... hurrah!

"But the generator I had in mind will be loading more than the 50amps you used for the sprinter example..."

well if you used only 2 or 3 metres of 22mm pipe and a handful of bends you could sill deliver the full meter limited 6m2 per hour to the engine"

"Amazing!... and what does that mean in fuel delivery terms"

well 6m2 hour would be an energy supply of 64.08 kwh, equivalent to about 6.6 litres per hour of petrol - as long as your engine is using less than that you'll be just fine... until you turn the gas boiler on that is!!!

so you are right, with the proper setup it can just be done with a domestic mains natural gas vapour feed - without storage/pressurisation... need more specifics about the fuel use of the engine vs the electrical output of the generator to work the cost differences though.

[v-lux]

So......you got a van yet....?

[ghost123uk]

So......you got a van yet....?

Obviously not or Jim would have no time for working out that VERY interesting (to me) set of stats

more specifics about the fuel use of the engine vs the electrical output of the generator to work the cost differences though

Jim, it is just summat I have often fancied, cutting my dependence on the main electricity supply. I looked at Lister Cold Start Diesels (~£1000) running on various fuels, they have an adjustable compression ratio and can be made to run on just about any "oil". Plus they are so over engineered that they run VERY quietly. Plus you can re-coop the heat energy from the motor and the exhaust.

However a modern, small 4 cylinder OHC engine could compare in terms of volumetric efficiency on gas.
I never sat down for long enough to work out the stats though, esp with regard to comparing costs of liquid LPG and mains gas.

By the way, I was thinking a 1.6 Ltr modern motor at modest RPM (quietness) might = 20HP, therefore around 15 KW / Hr allowing for losses in the system. I reckoned on around 2 Ltr per Hr of either Petrol or LPG (insignificant difference in calorific value) therefore ~£1.80 per hour on road taxed LPG (the mains gas cost is COMPLETELY unknown to me per KW/Hr, always wanted to compare = hence my first post on this. Also there is available heat from the motor and exhaust that can be used (even to power a fridge !)

It should be noted that the set would only be run for a small part of a day, being used to charge up a commercial sized "inverter", for want of a better description, actually it would be a large "UPS", they are very cheap second hand and act as an energy storage device - @, Jim I guess you know all this )

See, we are not off topic = "Ideal electrical set up???"

[v-lux]

Mental, .....you lot are mental....

[Mocki]

you lot need to actually get out camping instead of spending endless hours discussing the figures of everything.


for normal use, a 85a leisure battery and a 40amp 4 pin relay will be fine.

there is a fair bit of electronical gadgetry in my bus, and i need no expensive jelly battery.

spend the saved money on more sensible powered equipment - dump the laptop mains charger, and get a 12v step up powersupply , uses less than half that of a inverter and mains charger, charge the laptop when the engine is running.
same with the TV and DVD rubbish.

[ghost123uk]

you lot need to actually get out camping instead of spending endless hours discussing the figures of everything.

Agreed but our camper is STILL away getting a PROPER body resto. Been 5 months so far and they told me 8 to 12 weeks ! So what with that and the fact that us old farts (Gill and I) are pretty much fair weather campers there is not much to do other than rabbit on about stuff !

Can't wait for the forthcoming hip replacement to be behind me, our camper to come back, the spring to be here and my forthcoming retirement. THEN we will be out all over the place doing LOTS (and typing less on here !)

[nesty]

I heard my name mentioned so thought I'd put some input in.

The set up I have

1 x 110ah ecsol leisure battery which fits in the passenger seat well. Though this goes dead in 2 days!

Additionally I have 2 X T105 Trojans. These batteries are ace! They really give you decent power for small space. I have mine connected up in serial circuit making 6v to 12v and they just behind the passenger seat in a box. Takes up a very small space. I can post a photo up of them connected up.

These are charged via raw compentents split relay charger. Again nice piece of kit for £50.

The leisure batteries power a busbar fusebox and everything leisure runs from that. Stereo, lighting, heater tv etc. (the fridge runs off gas)!

I did a month in Scotland in 2010, never required 240v pick up. in 2011 i did a month in Wales again no pick up required. Personally these batteries have paid for themselves 4 times over as I never pay the extra £4 a night for pick up.

It's a no brainer for me!

[California Dreamin]

You did a month in Scotland and then another month in Wales....sounds really good until you think about it...by a month you don't actually mean 4 weeks without starting and moving.

Martin

[nesty]

I was moving in those areas going from point to point on a daily basis.

[GoosemanG40]

Hi guys!
I am new to the Forum but have been a total Duber since i was 18 so I know I'm among like minded fellows,
First I'd like to say that this hole thread has been a great help in my desission on my electrical set up, Trentjim and V-lux i hope you can take the time out to respond as I value your input and am having to do a total box van living installation.
I've owned my T4 for a few years now and have been living out of her for longer than i can recall, for instance this winter I have been working off the coast of Essex and been living the van life since early november 24/7 except Christmas of course. the old Gal and I have been to all four corners of Great Britain many times and taken a Surfing trip all the way down to the most southerly westen point of Europe, Its been a blast and a love affair one which my wife has had to except lol, I even preposed in the van so you can guess that having to sell her would be heart braking...

well yes it is but have faith she's going to a good home, almost a retirement home. A very good friend of mine is going to buy her and fix her up new and take her to volks meets and shows Waahaaayy!!

So on to my reason for writting to you fellows. I work alot out of London and since Jan 03 this year London is out of bounds for the Old Gal (Low Emmission Law) WANKERS!! so I am curently looking around for a decent candidate van, I've got my EYE on the Vivaro. I know I know its not a Volks but you try buying a T5 on my Money thats kitted out
It has to be an 04 05 06 ect plate to meet the Low Emmission law standeds, so moving on... My work is coming to an end and my life with the Old Gal is too so come Mid March I'm going to be in full Camper fit mode only one prob, I'm not emploid for my math skills and I mean it....
Taking on what you all said i'm looking to have this sort of set up.

First my Needs. power enough to run

Eberspacher 24v Airtronic (ill tell you why)
A ectrical mini bar fridge on pemitly
laptop for at least 4hrs a night
mobile phone charge per night

Fit

x2 Trojan 12v 110s
Sterling Battery to Battery charger + Remote control
X3 55w solar panels eventually
a more than adiquate converter for the Eberspacher
the abillity to Weekend overnight mains charges
a volt digital display screen or guage

OK school boy error

Before i consorted the interweb and this forum, I bought a Eberspacher 24v Airtronic DOH!! Now I can either sell it and get a 12v or use it with a Converter so it runs fine, I know that they drian on start up and I would be using it all of the night at low lvls so I need to first know should i replace or work with what i've got?????

otherwise there is no seious changes to my fit and needs only i need a weeksworth of power with a little bit of driving per day call it 15miles.
and the 60mile+ drive home per weekend there and back.
I really would love all your input possative or negitive, honesty is the best policy
All the very best
Goose

Ps
I will document all my works by photo and link to hear so you can all see how i do

[kevtherev]

Trentjim and V-lux i hope you can take the time out to respond as I value your input

well that's me out then.. good luck with your T thing

[ghost123uk]

Hi Goose, quite a first post there

Re the Eber = no big problem using the 12 to 24 v converter, a bit of an efficiency loss but not enough to worry about.

First my Needs. power enough to run
A electrical mini bar fridge on permanently

The rest is just normal / low use, but how much current (Amps) does your fridge use ?
All the fridges I have seen would hammer even the best battery in a few hours.

[trentjim]

Dont listen to anything I say!!! - Its all theoretical... I dont even have a van yet!
the three panels are a good start, but dont think that you'll get much value out of them in winter and if you know where its going to be parked just make a note if there are trees or buildings to interrupt the sun nearby

[GoosemanG40]

Hi all!
And of course kev your input is very much welcome, i just took on what trent and v- said.

Oh i forgot about the two lights to add to the list doh!

Ya thanks Ghost, ya am thinking i might go with the converter idea, cheers.
The fridge is not bought yet as im doing all this from a bardge off the coast, arn't Andriods Great! Lol.
I sappose the first Q is what amps range is siutable, the fridge doesnt have to be great all its gotta hold is milk and meat or hold a 6 pack for exsample.

Mr THEARY (trent) my only reservation with the pannals is theft so im ganna have to ponda onit and come up with a cunning plan, oh and it doesnt involve a ternip lol

Thanks guys
please any more ideas welcome would love to hear from you all

Goose