Issues charging phone with CB

Hi all,

I am having trouble getting my phone to charge when riding. I have previously wired a USB charger and a switch (both from eBay) to the battery and this used to work fine on my old phone (Samsung Galaxy S3). Now I have a new phone (LG G3) and although it says it is charging when I connect it to the USB port it actually discharges at the normal rate as if it is not connected to a charger.

I just measured the voltage on the bike battery - seems to put out 13V at idol and about 14.3 around 4000 rpm if this helps. Also when I have been testing this they have been pretty long motorway runs where rpm is consistently 4000-6000.

I think this is the charger I bought http://www.ebay.co.uk/itm/Motorcycle-Lite-Waterproof-USB-Power-Port-Charging-interface-Iphone-Ipad-GPS-/181283055205?pt=LH_DefaultDomain_3&hash=item2a354fe665

Anyone have any ideas?

Cheers

I have one of these http://www.demon-tweeks.co.uk/motorcycle/gps-and-navigation/digitek-moto-charge-usb and I've noticed a similar thing. I am a BlackBerry clinger-onner (  ) and upgraded from the Q10 to the Passport (AMAZING phone btw) and with the Q10 the charger worked fine whereas now with the Passport it charges very very slowly, especially if I'm using the phone for sat-nav. It doesn't discharge though.

I think it's to do with the fact that the new phone has a whopping 3450 mAh battery. I can't find the specs for the USB charger (what current it puts out) but I'm sure that's the issue.

I see that your LG G3 has a 3000 mAh battery, but that charger puts out 1A according to the eBay listing. My phone charges fine with a 0.75A charger so...hmmmm...might be worth somehow measuring the output of the charger but I wouldn't know how to do that on a micro-USB plug...

might be worth somehow measuring the output of the charger but I wouldn't know how to do that on a micro-USB plug...

I did try an app that supposedly tells me what current the phone is drawing but on the bike it didn't seem to get a reading that made sense (too small?). However in my car, through the cigarette lighter port, I get steady 1A. I can't think why the two should be different - the car battery, although bigger, gives out a similar voltage. But I'm no expert with this stuff.

btw nothing wrong with a blackberry I had a Nokia N72 (blackberry clone) far longer than I should have purely because it had a keyboard and to this day I still think it is a lot better to have a real keys than touch screen when typing!

I've had this issue too.And I think I know what's wrong. My Galaxy S3 used power faster than my DIY-charger could supply it - which is a Bad Thing when you're depending on it as your satnav, touring England.

I was puzzled.

Luckily, Maplins had a small USB-current/voltage-snifferdevice which told me that the 2A charger didn't supply more than 400 mA, which is just enough to slow down the discharge rate - while still showing the 'Charging' sign onscreen.

So, I took away the USB extension-cord. And voila - full power! Even with the engine off.

Which brings me to the conclusion that the USB cable must be a suitable one.

So: Try changing the cable between charger outlet and your phone.

So: Try changing the cable between charger outlet and your phone.

Interesting you should suggest this because on the way home from work today I did just this as a long shot and that not resolving the issue led to me posting here. But it could still be related to this because I originally had a USB extension cable and a USB cable running from the USB port to my phone and replaced this with a single USB cable. The problem is this cable is even longer! I just thought it might have been of better quality, plus doesn't have the join in it.

I've hard wired the USB port under the seat so I need quite a long cable to get to the phone holder on the bars but I will experiment with the phone under my seat with a short USB cable and see if this makes a difference.

Do you think the length of normal electrical cable also suffers from the same effect? I ask because I have a fair amount of it in this circuit wrapped up in the bike where I was too lazy to cut it down and solder it together.

Which brings me to the conclusion that the USB cable must be a suitable one.

I just found a tiny (10cm) USB cable so tried that with the engine off and satnav (screen) on for 20 minutes and guess what... it charged up quite a bit. So I can back up your conclusion and it seems a suitable cable = a short cable : )

So I will rearrange the wiring so the USB port is near the bars/phone and I should be good.

Thanks!

I bought a 12v regulator, after my supply caused serious damage to a £60 camera device running from it.

I've had similar problems, amperage delivered is no longer sufficient to keep the phone charged with the more modern power hungry devices. I'm going to try a shorter USB lead, as well as shortening the electrical cable - can't do any harm! Thanks for the advice.

However, what's the best way to attach the USB charger to a CB? Ideally I don't want it hooked up to the battery directly, I'm want it ON/OFF with the ignition... Is there a clean, neat, and reversible way of hooking it up somewhere?

Cheers,

Tony

Run it through a relay - I have  40A relay that takes its signal from an ignition controlled wire (don't ask me which one, you just need to find one). A scotchlok is suitable for this. The main power comes strict from the battery via a fuse.

Stooby2 wrote:Run it through a relay - I have  40A relay that takes its signal from an ignition controlled wire (don't ask me which one, you just need to find one). A scotchlok is suitable for this. The main power comes strict from the battery via a fuse.

If you have a suitable ignition controlled wire, not sure what the point is of running it through a relay?

Does anyone know how to find an ingnition controlled wire easily? Or is it possible to connect via the fuse box somehow?

Thanks for the tips!

The ignition controlled wire may well not be able to carry the extra load and/or drawing off extra current might stop the thing it was powering from working properly or blow the fuse protecting that part of the circuit. A few milliamps to power a relay is not an issue.

I've just had my right hand side cover off and it's the blue and black wire coming out of the bottom of the fuse box I've used.

On my bike the output of the relay goes to a terminal block and I have connected my hot grips and a 12v socket.

Stooby2 wrote:The ignition controlled wire may well not be able to carry the extra load and/or drawing off extra current might stop the thing it was powering from working properly or blow the fuse protecting that part of the circuit. A few milliamps to power a relay is not an issue.

I've just had my right hand side cover off and it's the blue and black wire coming out of the bottom of the fuse box I've used.

On my bike the output of the relay goes to a terminal block and I have connected my hot grips and a 12v socket.

Aaah now I read you. The relay is just used to catch an ignition signal - closes the circuit if current is detected ; while the power is actually drawn from the battery. Presumably the relay will draw less power than a USB charger / cigar lighter (with no device connected to it of course) connected directly to the battery?

Although using a relay to connect directly onto the battery seems critical for power hungry devices (hot grips), not sure how essential it is for phone chargers, which draw 5V / 2A tops. I suspect the extra power draw is minimal in comparison to the headlights, for example. Nevertheless it seems like good practice, and can't do any harm. That, and shorter wires/cables, should all help! I need to get hold of some scotchloks and a relay.

Any advice regarding the actual relay? Presumably something small, simple, yet adapted to the voltage/amperage (anything to look out for)?

Thanks again for the good advice (although I've been hogging someone else's post - sorry about that!)

Tony

The one I bought (Digitek Moto-Charge) connects directly to the battery but automatically shuts off once battery voltage drops to a certain level, if you leave it charging whilst the bike's switched off.

I had a Digitek charger before but for some reason my S3 didn't like it, kept saying it was over heating and would shut down, not sure what that was about? Instead I bought a USB socket, wired it direct to the battery and a put a small switch on the bars to turn the circuit on and off which is another option if you don't fancy going down the ignition route.

Ayep wrote:

Any advice regarding the actual relay? Presumably something small, simple, yet adapted to the voltage/amperage (anything to look out for)?

Tony

This is the type. Most car spares places sell them as well. Ebay is good for Scotchloks and also the crimp terminals.

http://www.ebay.co.uk/itm/AUTOMOTIVE-12V-30-AMP-40-5-PIN-RELAY-DC-CHANGEOVER-CAR-BOOT-BIKE-/160703035829?pt=LH_DefaultDomain_3&hash=item256aa5b9b5

Fantastic. Thanks you all for the ideas

(A mechanical switch is also a secure way of doing it, simple but not idiot-proof : the potential flaw here being me, if I forget to kill it after use...! On that basis, a relay seems a safer bet...)

On a side-note, I contacted the vendor. My current USB charger only lives up to a 1A output. Back in the days this was sufficient for most devices. More modern ones should push up to 2.1A - so for those of you who are out there to buy one, make sure you get a 2A one...

An illuminated mechanical switch might help.

(A mechanical switch is also a secure way of doing it, simple but not idiot-proof : the potential flaw here being me, if I forget to kill it after use...! On that basis, a relay seems a safer bet...)

An illuminated mechanical switch might help. 

It's true! I used to forget now and then although with the phone unplugged it would take some time run the battery down I reckon. On mine I have a GPS tracker (which is basically another phone) on the same circuit and once accidently left the switch on for 3 days without riding with no problems. Either way the relay idea is probably the slicker solution!

ceejay wrote:I bought a USB socket, wired it direct to the battery and a put a small switch on the bars...

What???


Hopefully there was an electronic bit in there too, as your battery is 12V, while USB is 5V. Feeding attached devices more than twice their rated voltage is no good idea.

Relay: In my eyes irrelevant, as your 1A charger will consume no more than  approx. 5W. I've simply taken the 12V from after the fusebox on a switched circuit.

Getting the rated power out of your USB: Cable length seems less important than connector quality. You see, the USB charging circuitry is semi-intelligent and uses a simple measurement of resistance (AFAIK) to decide what maximum current to feed. And cable in itself is a quite good conductor Connectors aren't necessarily that - who remembers the Peugeot car model that  was famous(?) for catching fire? Bad connector + high amperage -> heat -> fire.

[size=13]@ceejay wrote:I bought a USB socket, wired it direct to the battery and a put a small switch on the bars...[/size]

What???

Yeah sorry not literally a USB socket but a USB port unit designed for 12-24V batteries - output = 5V 

Getting the rated power out of your USB: Cable length seems less important than connector quality. You see, the USB charging circuitry is semi-intelligent and uses a simple measurement of resistance (AFAIK) to decide what maximum current to feed. And cable in itself is a quite good conductor  Connectors aren't necessarily that

Good to know, this makes sense.

Some usb cables only carry data and aren't designed to charge as well!

peatrich wrote:Some usb cables only carry data and aren't designed to charge as well!

This has to do with how the two 'middle' connectors are wired - straight-through or not i think. Device on the far end can then signal Hi/Lo charging current by 'replying' with a given voltage.

So, if wrong - or no - voltage is sensed by the charger, this signals LoCharge.

A random link to the issue at hand:
http://www.eetimes.com/document.asp?doc_id=1279469

I had a problem using a bike charger to power my tomtom satnav while touring and had to buy a tomtom car charger before it would put enough poeer to the unit to get past the home screen!

I did a decent run yesterday and while I was at the event I used my underseat facilities to recharge my helmet, satnav and phone (on the journey up). I have a utility socket (not a cigarette lighter) and a multi power adaptor as well as the previously mentioned 12v to USB adaptor. Life would be much harder without these!

Haven't got around to fitting a socket to this bike yet.  I was considering a dedicated usb plug but after this thread I might just stick with the tried & tested cigarette lighty type socket with usb adapter plug.  If only I could work out a better place to mount it than under the seat.