12V socket - poor charging

[glasgow]

Hello all,

Few years ago I installed a car socket adaptor but I recently noticed it struggles to charge my phone/satnav. I also noticed some electric noise interface with my starcom while the phone is on charge.

The adaptor has a combination of cigarette lighter jacks (X3) and USB output (X2) and it takes its input directly from the +ve battery lead. Here is the technical details:

output rating: 60W
max load 5A

Cigarette lighter jacks:
output voltage: 12V
total output current max4A

USB connections:
output voltage: 5V 
output current 500mA
output rating max: 2.5W

Is there anything I can do to improve the charging power or it is time to bin (any suggestion for a good one please?)

Thank you

Ahmed
 

[SM25T]

How many devices do you plug in at the same time ? These multi-way things don't handle many devices. You say input from battery + .... where is the -ve connected ?

[Jonathan Kay]

At least three issues there:

Charging current

The maximum charging current for some devices is surprisingly high, eg 2.1 A for for iPhones... greatly more than your 0.5 A. This *isn't standardised across sockets in the same way as the USB power and data standard that we all love/ hate/ rely on. And several will offer different maximum currents in different outlets of the same device.

You should probably look for nominal 2 A in all of the USB sockets of the replacement.

Electrical noise

This has come up before, and I warned about it only yesterday. I shouldn't think there's anything you can do about it.

Accessory sockets

... and it takes its input directly from the +ve battery lead.

Mine also comes straight from the battery, rather than through a switched feed or battery isolator. You should have a fuse in there...

Jonathan

* AFAICT the widespread use of USB as a power bus wasn't foreseen. There is now the USB Battery Charging definition but it doesn't seem to help much in avoiding this type of problem. That article describes the latest initiative aimed at sorting this out. And this was the topic of my first first full and frank exchange of views on BlatChat. :-)

[Jonathan Kay]

... or it is time to bin (any suggestion for a good one please?)

Yes, but I don't know which... I'd like one "cigar lighter" socket that grips the plug well, and two USB sockets with enough oomph, and no noise. Panel or surface mount.

Recommendations, please.

Jonathan

[Paul Deslandes]

Electrical noise from USB chargers is very common and comes from the high efficiency dc/dc converter that 'transforms' 12 volts to 5 volts. RF interference to radios and phones can be reduced significantly by adding ferrite chokes to both the input and output cables, such as often seen as a tubular bulge on many mains adapter cables.  These could be bought from Maplin who have very sadly gone bust but if they're still trading from a branch near you they may have them in stock, otherwise RS Components or Farnell.  They should be fitted as close as possible (very) to the converter by passing the cable through the middle, looping as many times as will fit.  Two or three turns is probably optimum. Separate chokes required for input and output cables.

Audio noise to the Starcom is a bit more of a challenge but can likely be improved by putting the Starcom earth and power leads directly to the battery (plus fuse in the 12v line), making sure that it isn't connected to chassis anywhere else, e.g. mounting bolts etc, and don't 'share' the supply cables with anything else.

My Terratrip intercom had the most awful whine which was only cured by modifying the pc board layout to get rid of the offending earth loop.  My offer to do the same for any member's Terratrip pro intercom with alternator whine is still open.

Paul

[glasgow]

Thank you all

Ian,

I only use one device at a time as I have another dedicated cigarette lighter socket that was already installed by CC when I bought my car

the -ve is connected to the chassis point at the windscreen wiper motor.

Johnathan,

Thank you for your suggestion. I thought any of the 3 cigarette lighter jacks will produce the same output but may be time to do some tests.

However, As I said above it was working fine for a few years. Now its poor outlet power are affecting both USB outlet and cigarette lighter outlet

And yes I do have a fuse between the battery terminal and the sockets

Paul,

Yes I do have a dedicated +ve and -ve lines for my Starcom and they are connected directly to the battery terminal and not shared. 

Thank you for the suggestion about the ferrite chokes. will keep it in mind

[Jonathan Kay]

I thought any of the 3 cigarette lighter jacks will produce the same output but may be time to do some tests.

Agreed... they're usually passive connectors. it's the USB bits that might not supply enough current, and might vary between sockets on the same device.

Jonathan

[Comp Sec]

I use a Hunda multi , 5 USB outputs, max 2.4A per output, 10A total.

https://www.amazon.co.uk/gp/product/B014KNTKMG/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

[Jonathan Kay]

Current ratings look good. Do you have an intercom or can you otherwise comment on electrical noisiness?

Thanks

Jonathan

[CaterBram]

I don't use intercom, but do charge Phone, Ipad, GPS, and sometimes run a bluetooth speaker.

[Jonathan Kay]

Thanks

Jonathan

[anthonym]

poor outlet power are affecting both 

that's a symptom typical of fried wire. Is any part of the feed stiff, which would mean heat soak has cooked it?

The older the installation, the further away from the heat source may there be fried wires. A meter will (eventually) show reduced voltage where it should be 12v, though in the earlier phases of this process it only manifests when the wire has become warm/hot. Simplest fix is replace the wire, rule out the prospect, but a bypass wire can determine if the problem goes away.

edit: all that said I feel it's unlikely, but worth a quick check.

Anthony

[Jonathan Kay]

#*8:

If I used one of those I'd remove the plug and hard wire it to ensure a decent connection.

Jonathan

[CaterBram]

Thats exactly what i've done with mine.

I only run with aero so i've actually wired it from the Heated windscreen switch.

[anthonym]

thanks Jonathan, I just ordered three of these: https://www.ebay.com/itm/222727715767

Six port version. Should tidy up the snake pit in my car.