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Invertor & Split charge

Posted: 04 Apr 2014, 21:56
by Jim San
First up - i am electrically un-savy.

I'm fitting out the new van as a proper camper with lesisure battery etc etc. Never been down this route before as we've always been very basic in our vans and not felt the need for electrics (gas fridge and cooker etc + charge phones from 12v euro plugs).

I'm intending on running a compressor fridge (have been told lesiure bat that will fit under drivers seat will be about 80ah which wont run the fridge effectively - so going for 110ah and fitting it somewhere!)

So I want a split charger to keep everything topped up :) (I know what they do but I have no idea about ratings)
I want an invertor - now i'm lost!!! do I want one? I need convincing please. am I missing out on something here? What could i do that i couldnt do on a 12v plug?

An Eber heater (at last) i understand these need constant supply from leisure bat when working - is this a minor amount or a serious drain on the juice

other things will be all low volt led lights, CD player,

I'm going to get it all fitted by a chap who knows one end of a fuse from the other but I need an understanding of what i need to spec. cheers

Re: Invertor & Split charge

Posted: 05 Apr 2014, 06:58
by itchyfeet
Invertor gives you 240v and enables you to use 240v gadgets such as phone and tablet chargers, tv etc
maybe you can get 12v adaptors for these gadgets but often they are mors expensive than an invertor
you can buy one to plug into a ciggy lighter socket if you think you wont use it much

Re: Invertor & Split charge

Posted: 05 Apr 2014, 08:57
by Jim San
itchyfeet wrote:Invertor gives you 240v and enables you to use 240v gadgets such as phone and tablet chargers, tv etc
maybe you can get 12v adaptors for these gadgets but often they are mors expensive than an invertor
you can buy one to plug into a ciggy lighter socket if you think you wont use it much


Nice one Itchy Feet, that helps a lot. We dont have a TV (and never will but thats a different story :lol: ) We dont take anything of any great value like laptops etc - although I think that may change as tablets are becoming very handy - but maybe one of those ciggy lighter ones would suffice.

So Invertor then!! is doing the job of a step down transformer? wheres the inverting coming into it? and why if we can run 230v from a 12v source dont we do it at home (i may be a little slow here) :|

Re: Invertor & Split charge

Posted: 05 Apr 2014, 09:10
by itchyfeet
No an invertor makes a high voltage 240v ac power source from low voltage 12 or 24vdc power source
a transformer usually turns ac high voltage into ac low voltage but can be used both ways
a power supply usually turns high voltage 240vac into a low voltage dc such as your phone charger

Re: Invertor & Split charge

Posted: 05 Apr 2014, 09:17
by itchyfeet
We dont use invertors at home because its inefficient to make and conduct electricity at low voltage dc, its made and conducted at very high voltage ac, so we have products that work of ac because thats how its most efficient
Often they have an internal circuit to drop and rectify this to low voltage dc to supply electronics in the product.

so your lap top needs low voltage dc but probably not 12v exactly, you have a battery in your van but to buy a 12v laptop power supply will cost more than buying an invertor and using your mains power supply that came with the laptop

it is however in efficient to power via an invertor as it will consume some power so if you have a 12v adaptor better to use it

Re: Invertor & Split charge

Posted: 05 Apr 2014, 09:26
by ghost123uk
So much to say :)

Jim San wrote: I'm intending on running a compressor fridge (have been told lesiure bat that will fit under drivers seat will be about 80ah which wont run the fridge effectively - so going for 110ah and fitting it somewhere!)

Compressor fridge, ok if you don't mind spending the extra dosh, but most folk use a gas powered fridge = cheaper to buy, silent, cheap to run.

With your apparently modest electrical requirements, a top quality 80Ah leisure battery, under the seat, properly looked after should be fine. Properly looked after means NEVER letting it fall below 12 volts charge (though some say 11.5 volts is the bare minimum). Buy an cut off thing so if the voltage falls too much, it automatically cuts off (like this one = CLICK HERE ;)


Jim San wrote:So I want a split charger to keep everything topped up :) (I know what they do but I have no idea about ratings) I want an invertor - now i'm lost!!! do I want one? I need convincing please. am I missing out on something here? What could i do that i couldnt do on a 12v plug?

Itchy is correct (as usual :)) in that a cheap inverter these days works out cheaper than buying separate 12 volt adapters for stuff like phones, tablets etc and in many ways are safer on your equipment, so yes, get one. I would say a 300 Watt one (hard wired) would be fine for charging stuff etc. Just remember not to plug anything into it that uses more than 300 Watts (it is always stated on a label on the equipment how many Watts it uses).

Jim San wrote: An Eber heater (at last) i understand these need constant supply from leisure bat when working - is this a minor amount or a serious drain on the juice

A minor drain really. iirc about 2 amps once it has fired up. Don't skimp on the wire sizes though as they use a lot more than that briefly during the "turning on" phase.

Jim San wrote: other things will be all low volt led lights, CD player

Cool :ok

Jim San wrote: II'm going to get it all fitted by a chap who knows one end of a fuse from the other

Sensible :ok

Re: Invertor & Split charge

Posted: 05 Apr 2014, 11:03
by Jim San
Brilliant info, cheers again guys. OK so I may as well bung in an invertor for convenience in the future.

Re the fridge, I guess as i haven't won the lotto i'll stick with the gas option, but with the plan to have an external tank fitted in the future so we regain the space taken by the gas bottle.
Having gas fridge will mean having a smaller leisure battery that can be conveniently housed under the drivers seat and negate the need for a bigger battery taking up the precious space under the bed.

Appreciate the guidance and info. Is there anything you would say I would absolutely have to have whilst its under the knife? May as well get it in now rather than once the interior is fitted.