Adding a second cigarette lighter.

ciaranmc

Hi,

I was wondering would it be possible to add a second cigarette lighter to a car by tapping into the wires running to the original cigarette lighter?

Cheers for all your advice.

Slidey

Yes.

You will still be only able to draw the same current as the single one though. Fine if you are only running a mobile phone charger and an iPod, no good if you want to run a fridge or the likes.

Make sure you thoroughly insulate all joints after.

ciaranmc

Slidey wrote: »

Yes.

You will still be only able to draw the same current as the single one though. Fine if you are only running a mobile phone charger and an iPod, no good if you want to run a fridge or the likes.

Make sure you thoroughly insulate all joints after.

Cheers for that. would you be able to run a laptop of it at the same time as a phone/ipod charger

daveharnett

ciaranmc wrote: »

Cheers for that. would you be able to run a laptop of it at the same time as a phone/ipod charger

Afaik, the cigarette lighter itself draws about 10 amps (120 watts), but that's only for a very short length of time - I wouldn't try pulling anything like that kind of power for an extended period - i'd worry about wires overheating. Check your laptop - what kind of voltage/current does it draw?

Are you planning to use a dc-dc converter to charge it, or an inverter plus the standard three pin charger?

ciaranmc

daveharnett wrote: »

Afaik, the cigarette lighter itself draws about 10 amps (120 watts), but that's only for a very short length of time - I wouldn't try pulling anything like that kind of power for an extended period - i'd worry about wires overheating. Check your laptop - what kind of voltage/current does it draw?

Are you planning to use a dc-dc converter to charge it, or an inverter plus the standard three pin charger?

My laptop says " Rated for 16.5Vdc 3.56A Max "
I have a inverter so would just use that to keep thing simple and then i could use the cigarette lighter for other things when im not using the laptop charger

Melodeon

ciaranmc wrote: »

My laptop says " Rated for 16.5Vdc 3.56A Max "
I have a inverter so would just use that to keep thing simple and then i could use the cigarette lighter for other things when im not using the laptop charger

Is that what's printed on the laptop or the charger?

If it's on the charger, it sounds like the output rating.
What you're looking for is the input rating, it'll be something like: 100-240v~ 50-60Hz 1.4A.
That last 'A' bit is the amperage drawn off the 'mains' by the charger.

daveharnett

ciaranmc wrote: »

My laptop says " Rated for 16.5Vdc 3.56A Max "
I have a inverter so would just use that to keep thing simple and then i could use the cigarette lighter for other things when im not using the laptop charger

That's about 57 watts. So from a 12v supply, that'll be nearly 5 amps. Add in heat losses from the inverter and laptop's "brick" and you're talking 7 amps. The draw from the ipod/phone charger would be pretty negligible in comparison, won't make a difference either way.

I'd be surprised if there was any problem - most cars have 15 or 20 amp fuses on the cigarette circuit, and I'd expect any modern car to use wire rated for currents well above the value of the fuse. That said, I'm not an electrician, a mechanic, or an auto electrician, so please don't take my word for it!

ciaranmc

Cheers for the help lads.

its printed on the underside of the laptop.

so you think id be ok running them off the same wiring?

Cheers

Melodeon

The figure you're looking for is the 'Input' rating on the power supply. That's what the load will be on your inverter/socket.

teednab-el

why dont u get an cigeratee lighter 4 socket adaptor? I picked up one in halfords and it is brillant as I can charge my ipod, sat nav and mobile phone together. It is safer also.

Fishtits

teednab-el wrote: »

why dont u get an cigeratee lighter 4 socket adaptor? I picked up one in halfords and it is brillant as I can charge my ipod, sat nav and mobile phone together. It is safer also.

Spot on.

Use an adapter, no worries re overloading the circuit. No messy wiring needed either.

ciaranmc

Cheers lads picked one of them up the other day works a treat.

Gary ITR

Also look into a car charger for your laptop rather than using an invertor

colm_mcm

Did this job over the weekend myself, decided I may as well take a few pics along the way.

Drilling pilot hole, first make sure there is enough clearance behind the dash to fit the socket.


Used a cone shaped bit to get the correct hole size, there is a notch on the socket that stops it turning, I filed a corresponding slot into the dash.


Next I tapped into the + wire going to the original cig lighter (this is in the centre of the socket, earth is on the outside), soldered the joint then insulated


For the earth wire, I used the casing of the stereo as an earthing point.


I used spade connectors to connect the wiring to the new socket





20 minute job, and so handy for charging phone and satnav at the same time.

Owen

I had to fit an inverter to my work car - the Rover 75 - for powering up my laptop to get colour codes/mixing quantities. I also use it for doing onsite soldering if I'm only installing parking sensors. The easiest way to do it was to use one of these - it's called an add-a-fuse.



It's rated for 15 amps, so you plug it into where your radio fuse is. One of the fuses powers your radio, and the other fuse is connected to the wire you see. Put your + lead into that, and crimp, and connect your - to a ground, and you have an instant power source with no load on an existing system.

Only problem is that they're about 10 euro a pop, and I can't find the manufacturer online. I was thinking of buying a thousand and reselling them, they're possibly the handiest thing ever.