USB Charger

[EQLEF]

Sorry in advance if this is a stupid question, but if the cigarette lighter socket is always live, even when the car is off, will the battery drain if I leave a USB charger plugged but not charging anything when the ignition is switched off?

[kis]

Only if you leave a device connected to it?

It's like a mains charger at home, if you plug your iphone charger in there (mains adapter and USB lead) and leave the switch "on" it won't continuously charge nothing... if you see what I mean? There has to be a device at the other end.

[ph001]

It will take a small amount of current even if you have nothing connected to it as you are still powering the internals of the USB charger - probably in the region of 10-20mA (if it has an LED on, which most do). That doesn't sound much but the total standby current for the whole car when locked is not a lot more than that, so you could be essentially doubling how fast your battery discharges if the car is in storage. It would still take several days though.

[EQLEF]

Thanks for the info, I left the USB charger plugged in last night.

[tomrdy]

Not sure what car/year you have but the cigarette lighter in my 2004 E85 is not always live - only hot with ignition

I am currently keeping my dashcam plugged into mine before my step down circuit arrives to hard wire and it's fine - on when car on IG, off when off.

[EQLEF]

Is a step down circuit difficult to fit?

[tomrdy]

You will need some basic circuitry experience but it's not really that complicated.

I ordered one of these:
https://rover.ebay.com/rover/0/0/0?mpre ... 2296903187

Basically, your cigarette USB plug is essentially a step down circuit of sorts - it takes the 12V and outputs 5V which iirc is what USB devices need.

My plan for my hardwire is to use a fuse tap to get a live wire from the fusebox, connect it through the step down and also a grounding wire. Then USB plug in and done!

Fuse 2 is a on-ignition - there's a diagram online somewhwre but you could also just use the cig lighter fuse as well (just something you know only turns on with ig).

[Bertz4]

Added a fixed USB charge point to mine as I got fed up of trailing leads from the standard socket. Has the bonus of showing the battery voltage as well. Need a brave moment or two to drill through the dash and a piggy back fuse adaptor into the fuse box.

[ph001]

I’d have drilled your cup holder rather than your dash on the basis that the cup holder trim is just a few quid to replace.

[Bertz4]

I’d have drilled your cup holder rather than your dash on the basis that the cup holder trim is just a few quid to replace.

Thought long and hard before I put it there but it’s never coming out unless It fails and needs replacing. Not really noticeable with the door shut anyway. If I was fitting it again I would go about 10mm to the right.
Rob.