Creating an inbuilt USB charger

[Clio 1.5 dci]

I"m trying to create a inbuilt USB charger with a cable so I can plug anything on the end, but the key point here is that whatever is plugged in contines to charge even when the engine is off. I thought about fixed a micro USB permenantly, but if I decide to get an iPhone I'll have to refit a new cable in directly to the live, so the USB option makes more sense.
The reason why I'm moving away from lighter sockets is simply because the charges themselves aren't that powerful, and they turn off when the engine turns off. Most times I need the phone to continue charging whilst I nip out and return within a few moments.

What I need to know is the best place of affixing this cable. In past I've done it with the radio live/earth wires - will this be okay?

 

[f0xy]

Car is 12v. USB is 5v. You need to convert it. Thankfully the far east have this covered. I use them to power GoPros and dataloggers in track day cars, never had an issue. If you want it all the time, wire it to a permanent live, if you want it on ignition, then an ignition live, etc.

 

[Clio 1.5 dci]

Thanks. But what's best to get the permanent live, is the radio cable?

 

[Ex-User (19928)]

Thanks. But what's best to get the permanent live, is the radio cable?

From the battery, with a relay running off the cigarette socket for example.

 

[RyanWXM]

running off the cigarette socket

Yep go of the cig lighter

 

[Clio 1.5 dci]

I was thinking of getting a direct power supply from the battery, and using an inline fuse with that connected to the main converter.
I've never fitted a relay before :/

 

[levaz]

From the battery, with a relay running off the cigarette socket for example.

Yep go of the cig lighter

But they wouldn't be permanently live?

Personally, I'd go direct from battery, with an inline fuse.
You'd probably be fine taking power from the radio live, but I wouldn't just so I didn't have to molest the standard wiring.

 

[Clio 1.5 dci]

Yes, it's supposed to be live permanently, I don't want the current to stop when the car turns off.
But running a cable directly from the battery to the cabin sounds like a mission. I don't really want to start taking my dashboard apart!

 

[Ex-User (19928)]

Yep go of the cig lighter

I don't mean power it from the lighter socket, if you have seen the wires they are very thin and whilst probably fine for the job I wouldn't want to test it. Use a relay on the lighter socket, that way you can have as much power as you like,

But they wouldn't be permanently live?

Personally, I'd go direct from battery, with an inline fuse.
You'd probably be fine taking power from the radio live, but I wouldn't just so I didn't have to molest the standard wiring.

Why would you want it to be permanently live ?

 

[levaz]

Why would you want it to be permanently live ?

I don't.

But OP requested solution to a permanently live method.

 

[@Spoonie]

Just buy a portable USB charger with pass through.
http://www.amazon.co.uk/dp/B00GFZP55O/?tag=cliospnet01-21

 

[Ex-User (19928)]

I was thinking of getting a direct power supply from the battery, and using an inline fuse with that connected to the main converter.
I've never fitted a relay before :/

http://www.ebay.co.uk/itm/40A-12V-C...arts_Vehicles_CarParts_SM&hash=item566eb906de

If you actually want me to explain how it works I will, but they're pretty straight forward.

 

[Ol’ Tarby]

If your wiring directly from the battery, and you want it permanently live then there's no need for a relay at all. Just a fuse close to the battery

 

[Clio 1.5 dci]

http://www.ebay.co.uk/itm/40A-12V-C...arts_Vehicles_CarParts_SM&hash=item566eb906de

If you actually want me to explain how it works I will, but they're pretty straight forward.

Yes please, I haven't wired one of these before, and if it'd help my situation I'm interested.

If your wiring directly from the battery, and you want it permanently live then there's no need for a relay at all. Just a fuse close to the battery

That's what I had in mind, a cable running from the battery to dash with an inline fuse.

BTW, are there any passageways from the battery through to the dash that are already in place to make this job easier?

 

[clioben182]

Bonnet cable rubber bung is best. Up behind glove box and no need to dismantle dash etc

 

[Clio 1.5 dci]

If you actually want me to explain how it works I will, but they're pretty straight forward.

Do I still need a relay if I don't want to hook it up to the vehicle's ignition? I suspect the USB module has one built it also?

 

[TarkMalbot]

No need for a relay as you need a switching power supply to turn the relay on and off so wouldn't be permanently live unless you wanted to have it on a switch so you can turn it on and off as required.

Also most USB devices only want a maximum of 3 amp input. Most of the cable within the car is fitted with a bigger fuse than 3 amp anyway so you should be safe enough using the stereo live. In fact I found yesterday that the alarm system was spliced into the stereo and hazard switch wires.

 

[Clio 1.5 dci]

No need for a relay as you need a switching power supply to turn the relay on and off so wouldn't be permanently live unless you wanted to have it on a switch so you can turn it on and off as required.

Also most USB devices only want a maximum of 3 amp input. Most of the cable within the car is fitted with a bigger fuse than 3 amp anyway so you should be safe enough using the stereo live. In fact I found yesterday that the alarm system was spliced into the stereo and hazard switch wires.

Got it. So using the stereo live would be the same as taking it directly from the battery as the stereo is a permanent live wire? I wanted to know if it was safe wiring it directly to the battery and putting a fuse in-line.

 

[TarkMalbot]

Direct to the battery with an inline fuse is the safest way to do it.

 

[TarkMalbot]

I just wrote a big long post with all the calculations etc etc but lost it.

1mm cable will be fine. If you need me to prove it I will but my Pizza is going cold at the moment.

 

[TarkMalbot]

I am considering one of these:
http://pages.ebay.com/link/?nav=item.view&alt=web&id=111540394455

 

[Ex-User (19928)]

Do I still need a relay if I don't want to hook it up to the vehicle's ignition? I suspect the USB module has one built it also?

No, the only function the relay offers is being able to get whatever current you want from the battery, whilst still having the benefit of being linked to ignition.

If all you want is a permanent live then you don't need a relay, but I would say take care as you don't want to get a flat battery just because you forgot you left something plugged in for a couple of days.

Likewise if you want something on the ignition that just happens to be a satnav or 1 phone charger, then piggybacking the 12v socket would probably be fine too.

 

[Owen92]

I'd use a relay hooked up to a switch, just so you can choose to leave it left on or not.
The whole point of a relay is being able to switch on a high current circuit using a low current. For example you could have battery cable running from the battery to the usb, but be able to control that circuit with a switch hooked up to the relay with a thin diameter wire.

 

[levaz]

I'd use a relay hooked up to a switch, just so you can choose to leave it left on or not.
The whole point of a relay is being able to switch on a high current circuit using a low current. For example you could have battery cable running from the battery to the usb, but be able to control that circuit with a switch hooked up to the relay with a thin diameter wire.

Why not use a delay timer instead of a switch?
So that once the ignitions been off for an hour, it cuts out?
That way OP could keep his phone/satnav/vibrator on charge whilst jumping in/out of car, but not have to worry about a flat battery overnight

 

[Owen92]

Why not use a delay timer instead of a switch?
So that once the ignitions been off for an hour, it cuts out?
That way OP could keep his phone/satnav/vibrator on charge whilst jumping in/out of car, but not have to worry about a flat battery overnight

My initial thoughts were this aswell, but as the OP is being extremely vague about the reasons he wanted it fitting.

 

[levaz]

I'm guessing pimp.
Needs to leave his phone charging whilst he goes in to sort out the business.
Comes back to the car later, phone charged, hasn't had to leave keys in ignition

 

[Clio 1.5 dci]

I'm having a problem installing this kit. I've got all I need, but for the past day I've been trying to look for an existing accessible hole through the firewall. It's driving me mad!
Can someone give me some guidance on passing the wire from the battery through to the dashboard?

thanks

 

[levaz]

Rubber grommet under the glovebox, it comes out under the header tank behind the matting on the firewall

 

[DannyR]

Why are people suggesting running this to the battery? Seriously?

Use the constant live to the headunit, buy another 12v socket from CPC, plug in usb adaptor, plug in usb and run through ash tray light hole or similar depending where you want it.

It's already fused, and your only pulling up to 2.5a more.