12v outlet fuse question

[clrd_2_lnd]

What should I use, I see some posts with 30a and some with 15a and one with 5a. I will use a Tom Tom 3rd Ed GPS and charge my iphone with it, what would be the difference between the three? Don't know much about wiring, + for pos and - neg and you need a fuse, that is where it ends for me!!

 

[alanrim]

Always a good idea to fuse as low as reasonable, that way any wiring fault will take out the fuse with much less risk of fire or wiring damage. 5A should be plenty for your use.

 

[Gobs]

I do agree with alanrim!
Never use a BIG fuse if not necessary: better protection.

5A is OK for what you expect to do. It allows you to use about 60 watts, much much more than one GPS needs!

Furthermore, try to settle your fuse the closest to the + battery you may do: your wiring will be better protected near all along...

Good luck,
Gobs

 

[SANGER_A2]

The highest phone/sat nav/usb charger I have seen draws about 2Amps. See what yours says on the label. It's a regulation it must say the output voltage/current etc on it. Then try to get the fuse that is 1 amp above that.

Don't go lower than the draw + 1 amp though!

 

[clrd_2_lnd]

Thanks to you all, I did the install yesterday and used a 10a, so if it blows I will change to a 5a, my GPS and iphone chargers have fuses in them already I found out so they will be fine and I will make the change if I have to replace the fuse.

 

[Gobs]

Hi clrd_2_lnd,

To be safe, better you do the opposite: first try a 5A fuse; if blowing go for a 10A (but I highly doubt that!).
Always go for the lowest fuse you may use...

By the mean what is the gauge of your feeding wires?
To be safe, 10A requires at least a 1 sqmm gauged wire!

IMHO

Cheers

 

[clrd_2_lnd]

Hi clrd_2_lnd,

To be safe, better you do the opposite: first try a 5A fuse; if blowing go for a 10A (but I highly doubt that!).
Always go for the lowest fuse you may use...

By the mean what is the gauge of your feeding wires?
To be safe, 10A requires at least a 1 sqmm gauged wire!

IMHO

Cheers

12v socket came with 16 gauge and I used the same to wire it to the battery, and the in-line fuse had a 12 gauge wire on it already and I just connected the 16 gauge up to that, 16 to 12 gauge in-line fuse to battery.
What I mean about the fuse is the power plugs for my GPS and Iphone already have a fuse built in and it is a 2a fuse for the GPS and I'm sure it is close to that for the Iphone.

 

[Gobs]

:thumbup:
Seems good to me, clrd_2_lnd.
A "not-so-long" 16 gauge wire is OK for a 10A fuse...

Just for info, have a look here:

http://www.engineeringtoolbox.com/amps-wire-gauge-d_730.html

They made a table gauge/amps for different wire lengths. Interesting...
The wire lenght to consider is from the + battery to the device and back to the - battery or the earth. So if your device is (for example) 3 feet far from the battery, and your device is connected to + and - battery you get a 3 feet + wire more a 3 feet - wire: that's to say 6 feet wiring.
Note this is given for a voltage drop of only 3%...

Furthermore, shorter is your wire, higher may be the amps (in a safe limit obviously)...

In line, you always only consider the thinner wire, that's to say the 16 gauge one in your case.

Cheers,
Gobs