Adding a 12V outlet
Discussion
I need/want to add a 12V outlet (where there is a blanking plate for one) in the boot of a car.
I assume the best answer is to supply direct from battery but thats not practical so I guess (again assuming) I can take the -'ve from any ground point and the +'ve from any close by source?
Its got a 20a fuse on it but having nearly caught a VW beetle alight 35 years ago doing similar I am a little cautious!
I assume the best answer is to supply direct from battery but thats not practical so I guess (again assuming) I can take the -'ve from any ground point and the +'ve from any close by source?
Its got a 20a fuse on it but having nearly caught a VW beetle alight 35 years ago doing similar I am a little cautious!
With anything like that you really do need to run it from either the battery or a spare fuse way in a fuse box.
As you say you are aware of the dangers but it needs to be fused at the supply end for protection & suitably sized wire used to allow for anything up to 20 amp to be fitted.
If you just piggy back any old 12v feed then it is extremely likely that circuit will be overloaded & that could 100% cause electrical damage/worse.
As you say you are aware of the dangers but it needs to be fused at the supply end for protection & suitably sized wire used to allow for anything up to 20 amp to be fitted.
If you just piggy back any old 12v feed then it is extremely likely that circuit will be overloaded & that could 100% cause electrical damage/worse.
What do you want to power and how much will it draw?
A couple of things to consider. Directly wiring to the battery will mean the socket is always live meaning if you leave something plugged in it will drain your battery.
If it were me id wire the socket directly to the battery but with a relay being switched from a power source nearby (ideally one that is a switched live feed, i.e only comes on when the car is running or accessory power) that way you can give the socket lots of amps, you wont overload whatever circuit you're tapping into and the socket will only go live when ignition is on.
That said, if you're unsure just take it to a garage or an auto electrician. This is a very basic job and they probably wont charge much and it will be done properly
A couple of things to consider. Directly wiring to the battery will mean the socket is always live meaning if you leave something plugged in it will drain your battery.
If it were me id wire the socket directly to the battery but with a relay being switched from a power source nearby (ideally one that is a switched live feed, i.e only comes on when the car is running or accessory power) that way you can give the socket lots of amps, you wont overload whatever circuit you're tapping into and the socket will only go live when ignition is on.
That said, if you're unsure just take it to a garage or an auto electrician. This is a very basic job and they probably wont charge much and it will be done properly
Crudeoink said:
What do you want to power and how much will it draw?
Not really relevant though is it?I say that because you just know that if there is a socket there at some point someone will go full on inverter etc.
Better to make sure it can do everything anyone might go for.
Crudeoink said:
If it were me id wire the socket directly to the battery but with a relay being switched from a power source nearby (ideally one that is a switched live feed, i.e only comes on when the car is running or accessory power) that way you can give the socket lots of amps, you wont overload whatever circuit you're tapping into and the socket will only go live when ignition is on.
Better still, good point.E-bmw said:
Crudeoink said:
What do you want to power and how much will it draw?
Not really relevant though is it?
Because if you want to be pulling 20-30amps it will need a supply cable and fuse to cope with that.
If you only want to run a 10w phone charger, you can fuse it for 1amp and potentially open op a wider scope of options.
See also if a switched supply, or permanent supply, is going to be prefered.
What car is it, can you find out from a owners forum/fbgroup where the factory outlet would have been connected?
Else another option is a fused supply run under the car from the battery to the boot. Not pretty, but no reason it cant be done safely, and often easier than taking it thorugh the inside of the car removing all the door cill trim and stuffing it under the carpet!
Else another option is a fused supply run under the car from the battery to the boot. Not pretty, but no reason it cant be done safely, and often easier than taking it thorugh the inside of the car removing all the door cill trim and stuffing it under the carpet!
dhutch said:
E-bmw said:
Crudeoink said:
What do you want to power and how much will it draw?
Not really relevant though is it?
Because if you want to be pulling 20-30amps it will need a supply cable and fuse to cope with that.
E-bmw said:
Crudeoink said:
What do you want to power and how much will it draw?
I say that because you just know that if there is a socket there at some point someone will go full on inverter etc. Better to make sure it can do everything anyone might go for.
E-bmw said:
Crudeoink said:
What do you want to power and how much will it draw?
Not really relevant though is it?I say that because you just know that if there is a socket there at some point someone will go full on inverter etc.
That said, you need to think about if you want power permantently live or not Tony. I personally always go for a switched live as I know i'll invariably leave something turned on / plugged in and drain my battery. But honestly Tony, without sounding mean, if you have to ask these questions it's probably best to take the car to someone else to do for you
was a power socket an option for the car when new, it maybe there is a supple there already, wiring harness are often standard across the range, just not plugged in to various options, so worth a look.
But if not the above answer of using a spare fuse in the main fuse box is the best option.
But if not the above answer of using a spare fuse in the main fuse box is the best option.
richhead said:
it maybe there is a supple there already, wiring harness are often standard across the range, just not plugged in to various options, so worth a look.
This is tomorrow's job... and if not...Crudeoink said:
But honestly Tony, without sounding mean, if you have to ask these questions it's probably best to take the car to someone else to do for you
^^^^ as mentioned, already caught one car alight fitting a fag lighter in the back of a '69 beetle (when I was 17)Thanks all.
normalbloke said:
Its an idea but its for Mrs21 who is very particular about her tyre pressures (can spot a slightly iffy tyre at 50 paces). She likes to check them at least once a week and the 12v in the front is used for a carplay jobby and no longer accessible.It will be simpler to add one to the front footwell somewhere.
Another time.
21TonyK said:
normalbloke said:
Its an idea but its for Mrs21 who is very particular about her tyre pressures (can spot a slightly iffy tyre at 50 paces). She likes to check them at least once a week and the 12v in the front is used for a carplay jobby and no longer accessible.It will be simpler to add one to the front footwell somewhere.
Another time.
Checking every week seems excessive to me, and more likely to introduce problems due to repeatedly unseating the valve.
If she's determined to do that, I suggest using a simple reliable mechanical gauge which needs no power.
When they need more air, batteries are so good these days that I prefer a LiPo battery powered pump over those awkward 12V wired pumps. You can charge that up anywhere with a USB power point. You probably have a few in the car already.
If she's determined to do that, I suggest using a simple reliable mechanical gauge which needs no power.
When they need more air, batteries are so good these days that I prefer a LiPo battery powered pump over those awkward 12V wired pumps. You can charge that up anywhere with a USB power point. You probably have a few in the car already.
GreenV8S said:
Checking every week seems excessive to me, and more likely to introduce problems due to repeatedly unseating the valve.
If she's determined to do that, I suggest using a simple reliable mechanical gauge which needs no power.
When they need more air, batteries are so good these days that I prefer a LiPo battery powered pump over those awkward 12V wired pumps. You can charge that up anywhere with a USB power point. You probably have a few in the car already.
Agreed. I have the above Sealey unit, which has been excellent, to maintain tyre pressures on two cars. So simple to use, just charge it in the car when you go for a drive, it doesn’t discharge if left for an age in the boot, and it works as a power bank if you’re in the sIf she's determined to do that, I suggest using a simple reliable mechanical gauge which needs no power.
When they need more air, batteries are so good these days that I prefer a LiPo battery powered pump over those awkward 12V wired pumps. You can charge that up anywhere with a USB power point. You probably have a few in the car already.
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