Auto electricians?

[NiceCupOfTea]

Hi,

Just need a spot of advice! I'm permanently wiring in a couple of accessories (GPS Inforad and mobile phone).

Both take 5v and so I am cannibalising a phone charger to go behind the dash.

Assuming I take a feed from the ciggie lighter or the ciggie lighter light (which I think is on the same circuit), will the phone charger be rated high enough to power both things?

The phone charger came with a 2A inline fuse - I can't imagine a charging phone and the GPSInforad will pull that much?

[benyeats]

NiceCupOfTea said:

Hi, Just need a spot of advice! I'm permanently wiring in a couple of accessories (GPS Inforad and mobile phone). Both take 5v and so I am cannibalising a phone charger to go behind the dash. Assuming I take a feed from the ciggie lighter or the ciggie lighter light (which I think is on the same circuit), will the phone charger be rated high enough to power both things? The phone charger came with a 2A inline fuse - I can't imagine a charging phone and the GPSInforad will pull that much?

Charging a 'phone could easily take over 1A the battery in a cell phone is often around 1800mA hours (or 1.8 A hours) and they can be charged in about an hour. If the 'phone is just being topped up then it is different, the charge circuit will start at high current then switch to lower as the battery approaches capacity.

Mind you if the 2A fuse is on the 5V side this is equivalent to a draw of approx 1A on the 12V side.

I assume ciggy lighters can provide more than 2A, check the fuse box in the car and see what rating that circuit is on for a guide.

Ben

[NiceCupOfTea]

THe car fuse is rated at 20A (for the cig lighter and "backup lights" whatever they are).

I was thinking that it was no worse than having one of those socket doublers that you can get in Halfords...

No idea whether that 2A fuse is overkill or not. It'll have to come out when I cannibalise it, but smallest inline fuse I can find is 3A...

The 2A fuse is on the 12V side of the voltage converter.

I seem to remember the one that came with the inforad saying 5v / 750mA (it's in the car) - so if that's what it's rated at presumably it won't pull any more than that

TBH I will use the phone charger once in a blue moon but nice to know it's there...

>> Edited by NiceCupOfTea on Monday 27th June 11:41

[parrot of doom]

The fuse does not protect the devices - it protects the cable. Get this wrong at your peril.

[NiceCupOfTea]

I'll be using high enough rated cable, but worried about melting the 12v->5v circuitry...

[Pigeon]

Chances are it will have a current limit in it so if you try to draw too much it simply won't work.