Hi everyone, interesting one, when I charge my phone with a cig lighter cable, there's not enough power to get the phone to actually charge if it's doing anything (using bluetooth and sat nav etc), in fact, it doesn't seem to offer any real charge at all and it drains very quickly. I bought a usb cig lighter adapter that claims to give 2.1V of power and I found when using this that the phone tends to hold it's charge or drains ever so slightly which is at least a move in the right direction however, when using this I get terrible radio interference which I presume to be a grounding issue - could anyone advise what I should be grounding differently (ie the cig lighter or the radio?) and if anyone has managed to get a phone charger that can output enough power to actually charge their phone when using it as a sat nav?

Thanks Polo geniuses!

Edited 17 June, 201412 yr by michaeldc

Michael,

The charger you bought claims to give 2.1amps as opposed to volts. They all should provide 5v (assuming your phone is charged via micoUSB) however this sounds like a classic case of cheap charger syndrome, let me guess, Poundland? eBay? Cheapest one on Play?

What type of interference and on what frequency? FM or MW? Or line-in? The answer to both your questions probably lies in the quality of the charger. Cheap chargers may be badged 5v, 2.1a however many of them run at less than 5v (some even as low as 3.5v) and most cannot produce a smooth 2.1a. Seriously cheap chargers are often 0.5a chargers rebadged and in one case I've seen a 0.3a charger rebadged as an iPad charger.

Regarding the interference, it may not be a grounding issue. If it's a particularly cheap charger, they can radiate 'noise' which can be picked up by the radio and therefore cause problems. You want a charger that is smoothed and shielded. A very good example of this is the charger that comes with Garmin sat nav devices. I bought one specifically for my dashcam as the supplied charger was noisy.

Edited 18 June, 201412 yr by Skezza

Hi Skezza, thank you for replying, you're right, it was a cheapo ebay effort that promised the higher charge rate, the one that came with my QI wireless charger also was a usb adapter that has the same issue. I then used a dedicated cig lighter to microusb that I received free from the carphone warehouse a couple of years ago but never had the opportunity to use.

I get terrible interference on MW and the some interference on FM as well, I haven't tried line-in aux because I'm waiting on a jack cable to arrive before I can try my ipod.

Could you perhaps recommend a good, smoothed, shielded and powerful cig lighter to microusb charger, finding one online that is open enough about the quality is difficult but I don't mind paying a little extra if it will eliminate this awful interference!

Googling for smoothed shielded car charger micro usb doesn't give many results!

Hi Skezza, thank you for replying, you're right, it was a cheapo ebay effort that promised the higher charge rate, the one that came with my QI wireless charger also was a usb adapter that has the same issue. I then used a dedicated cig lighter to microusb that I received free from the carphone warehouse a couple of years ago but never had the opportunity to use.

I get terrible interference on MW and the some interference on FM as well, I haven't tried line-in aux because I'm waiting on a jack cable to arrive before I can try my ipod.

Could you perhaps recommend a good, smoothed, shielded and powerful cig lighter to microusb charger, finding one online that is open enough about the quality is difficult but I don't mind paying a little extra if it will eliminate this awful interference!

Googling for smoothed shielded car charger micro usb doesn't give many results!

The reason you're getting terrible interference on MW is the reason I described above. The antenna effectively picks up the noise generated by the transistors stepping the voltage down to 5v. To prove it's not a grounding issue (or at least test), go and find a genuine 12v device (no step-down), literally any device, e.g. tyre compressor, heated seat, fridge, most sat nav's step down to 5v so check the plug, and then plug it into your socket and use the device. I'll put a pound on that there will be no interference. If there's any interference at all then it could be a sign of energy leaking and therefore a possible grounding issue or defective device.

Noise on FM is less common, but still plausible from a cheap charger. I personally get no noise on FM, no matter how cheap the device is, but it's possible that some sort of internal shielding inside the radio is preventing that.

If you want to try shielding your charger you can, buy some sticky back copper strips and cover the inside of the plastic casing. However that won't solve the slow charge speed.

How much do you want to pay? You can pick up a 2.1a charger by PowerGEN for about £5. They have tonnes of good reviews, but part of the problem is MW is a rather niche market nowadays. Finding someone who's actually used while listening to MW is rare to almost non-existent (speaking as someone who ONLY listens to 5Live). I can say from experience that Garmin sat-nav chargers are top class and push out a smooth 1amp. You could do with finding out the max speed your device will charge at. If it charges at 800mA tops, then 1amp will be fine as the extra 200mA can surplus some of the extra usage on the device. If you want to go all out cash-whore then this got voted the best car charger giving out an incredible 4.8amps (2.4a per socket), at £14.99 it's not cheap, but I'm bloody tempted myself tbh

http://www.ebay.co.uk/itm/like/131095034059?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0&ff12=67&ff13=80&ff14=108

Edited 19 June, 201412 yr by Skezza

Hi Skezza, I'm prepared to pay £15 if it'll sort this out! I like to listen to 5live and talksport (thought the reception for both is poor anyway in my area sadly). I want to make sure I'm on the right track here so if you'll bear with me, I'll lay out my set up.

My phone is the Nexus 5, my cradle is a QI wireless charger - the box gives me the following specs - Input: DC5V, 1500mA / Frequency: 110~205KHz / Conversion: <75% - it takes a micro usb connection into the cig lighter - the device seems good quality but the usb adapter that came with it, does not. If you think the Scosche reVOLT would solve the interference issue and provide a good charging rate then I am all down for spending £15. If you think the 2.1a PowerGEN will give similar results then all the better. I have no idea where I can find an official Garmin sat nav charger and ebay is awash with knock offs.

I can't stress this enough, I do not understand voltage, mA or Frequency with these things, I'm worried if it too powerful it will damage the charger or the phone (excessive heat?) but too little and it won't charge when using it as a sat nav with bluetooth enabled. Basically, I'm at your mercy and for the sake of a spending £5 or even £15 I wouldn't hold it against you if any advice didn't work!

Thanks for your time and thorough replies so far Skezza

Edited 20 June, 201412 yr by michaeldc

No problem mate, had all the same issues myself when I first got my Lupo. It's also made significantly worse on petrols thanks to the coilpacks, HT leads and spark plugs etc. So it needs a minimum of 1.5a, that's cool so any of the two chargers I posted would work. Frequency is not an issue really. Conversion means that there's about 25% energy lost due to the induction process (normal). I think the Scosche reVOLT would be much better yes, but having not owned one myself I cannot say 100%. I suppose the best way is to find someone with one and ask them to try on MW. Really, problems with RFI interference should be noticeable on almost all cars.

No reason the PowerGEN one won't work perfectly either and I'd be tempted to go for that first, although again, if you can find someone with one and ask them, they can say for sure. There are genuine Garmin Sat-Nav chargers on eBay too, the problem is I think they only put out a a maximum of 1.0a. There's the end of that then.

Basically, simply put, the voltage of a device will be uniform to whatever that product. E.g. most cars run at 12v right? So everything that runs on 12v can be run off car electrics. Why do you think you get people creating rather inventive and whacky devices on their car, such as 12v heating elements out of a travel kettle in their fuel tanks to warm the fuel in winter. USB is a standard and has always run at 5v, so all devices run at 5v. If your charger puts out less than 5v it'll be slow, if it puts out more, it'll potentially damage the device. Cheap chargers are unlikely to put out more, they usually put out significantly less voltage. As USB is a standard, you should never have a problem with USB chargers. Where you have to be careful is laptops and stuff like that. Some laptops have a 12v charger, other have 8 volt chargers, some have a 15 volt charger and some even have a 20 volt charger. If you plug a 20v charger into a laptop that only needs 12 volts, expect a bang and a dead laptop. The way I do it, I read the back of the laptop (there's a sticker usually telling you the required voltage) and then check the voltage of the charger.

Amperage is variable, but unlike voltage it is not something you should fear. People who say that charger gives out more amps so won't work with your device or will damage your device are wrong. Plain wrong. You can plug whatever charger you like so long as the voltage is the same. Fact. The higher the amperage, the faster it should charge, but it's the device that will effectively draw the current required. When you plug your phone into your computer, it'll charge at a rate of 500mA. When you plug it into your 2.1a wall charger, it'll charge at something like 1200mA. Ultimately, it'll charge twice as fast off the wall charger because it's drawing more current than the PC USB socket can provide, but it'll never draw more current than necessary and it'll never burn out because of it. In a lot of ways, the best chargers are the ones that can supply the most current in a smooth waveform.

Frequency isn't really important to be honest.

Edited 21 June, 201412 yr by Skezza

Amazing and detailed response. Once again very thorough and easy to understand! I think I'll read some reviews of those two you suggested and if both sets are good then I'll go cheaper to save money, if the other is significantly better reviewed I will pay the extra.

Surprised the USB adapter that came with the (seemingly very well built) QI charger appears to be no good, I guess that the shielding issue is prevalent in that particular adapter.

http://www.ebay.co.uk/itm/271466185081 was the item I bought. I think it's a pretty solid charger/cradle though it doesn't say anything about the adapter or even list it as something that comes with the item so I can't really complain about it too much!

Huge thanks again!

I'm tempted buy one of those myself. Hate having to plug in my phone!!

If you have a QI enabled device, I recommend wireless charging :)

If you have a QI enabled device, I recommend wireless charging :)

Got a Nexus 4.

Hi Skezza, I got the Scosche reVOLT and on first impressions... I am mighty impressed! My phone was on 99% when I got in the car this morning, plugged it into my QI charger via USB in the car and had bluetooth and sat nav running on my 20 minute journey to work. Got there and the phone was 100% depite the heavy use, it still charged. Exactly as I had hoped! The radio also seemed to play FM without any issue though MW was really rather ropey still.

There is still one slight problem though... I used the other port for my portable DAB radio which needs to be plugged into the power to boost signal around where I live, like an old charger I had, I needed to draw out the charger from the cig lighter, about half an inch or so until it worked which is very odd, the power was getting through but no sound until I pulled out the charger to a certain point and then boom, it worked. Is it likely this is a damaged cig lighter or perhaps a grounding issue? It makes no sense to me at the minute.

Hi Skezza, I got the Scosche reVOLT and on first impressions... I am mighty impressed! My phone was on 99% when I got in the car this morning, plugged it into my QI charger via USB in the car and had bluetooth and sat nav running on my 20 minute journey to work. Got there and the phone was 100% depite the heavy use, it still charged. Exactly as I had hoped! The radio also seemed to play FM without any issue though MW was really rather ropey still.

There is still one slight problem though... I used the other port for my portable DAB radio which needs to be plugged into the power to boost signal around where I live, like an old charger I had, I needed to draw out the charger from the cig lighter, about half an inch or so until it worked which is very odd, the power was getting through but no sound until I pulled out the charger to a certain point and then boom, it worked. Is it likely this is a damaged cig lighter or perhaps a grounding issue? It makes no sense to me at the minute.

Shame about the MW. As I said before, it's a strangely unique taste of radio and unfortunately, not enough people listen anymore. I am yet to understand exactly why my Garmin charger is so quiet, but perhaps I'll record a video for you and demonstrate just what I mean. I suppose it's possible that they've smoothed the charger and put additional shielding as well. Shielding isn't a tough job. You could do it with foil as a proof of concept, but most people use copper-backed tape. I need to take a video of it, because people are so surprised when I say it literally doesn't interfere whatsoever with the MW.

I suppose one thing you could try is touching your aerial, and seeing if it improves. If it does, it could be a grounding issue, but really, I haven't seen many occasions where this has been the case.

That to me simply sounds like perhaps the charger not fitting snug in the socket? The centre pin is the live, and the metal surround is ground, so as soon as plugged in, it should work!

The charger itself is standard size and fits fine. When pushed all the way in, the QI charger works without issue as far as I can tell but then it's not obvious it's working correctly or just working. With my DAB radio (which gives very clear sound for Talksport / 5L / 6M etc) it's a case of getting the charger in the right position, it's bizarre. I have to pull it out at least half an inch for it to work. There must be some damage somewhere? :/

I can't even google it because I have no idea how to correctly describe my situation!

Edited 26 June, 201412 yr by michaeldc

Interestingly I noticed that when fully plugged in, the DAB charges but has no reception, however when I touch the sides of the charger with the sides of the cig lighter hole, it gets perfect reception. I guess the radios reception is boosted by the car but there must be a grounding issue or a damaged cig lighter causing issues somewhere because the power section is working but radio interference is abundant when fully plugged in. It's a very odd one and I am not at all sure why it is happening. Hopefully my auto-electrician can hurry up and get out to me, he has a bunch of jobs to do now...

Very possible the cig lighter is broke, but they aren't exactly complicated.... so hmmm.