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Looking for an AC to DC power converter for USB car chargers

Zmanbaseball2

Zmanbaseball2

macrumors 68040
Original poster
Aug 24, 2012
3,542
11
New York, USA
I am looking for an AC to DC power converter that allows me to plug my car chargers in my house. It must support 9.6 amps/40 watts of power so it can support these:
Aleratec Quad 4 Port USB 9.6a (2.4 amps x 4) Rapid Car Charger for iPhone, Smartphones, iPad and Tablets
http://amzn.com/B00EP3IWG2
[NEW RELEASE] Saicoo 8A/40W 4 USB High output Ports Car Charger(83CM Cable Length), with separated ON/OFF Switch /LED indicator and one Silicone Paste and Velcro, Charger for iPhone 5S, 5C, 5, 4S, 4; iPads and iPods; Samsung Galaxy S4, S3, S2, Galaxy Note 2; Motorola Droid RAZR MAXX; HTC One X V S and more - White
http://amzn.com/B00GANTT94
I live in thE USA so it has to be USA power prongs. It also must be on amazon.
I hope someone can help me.
Thanks!
 
Zmanbaseball2

Zmanbaseball2

macrumors 68040
Original poster
Aug 24, 2012
3,542
11
New York, USA
T5BRICK

T5BRICK

macrumors G3
Aug 3, 2006
8,312
2,385
Oregon
Zmanbaseball2 said:
This one will work with the car chargers I said?
Schumacher PC-6 120AC to 6A 12V DC Power Converter
http://amzn.com/B0012BL8LG
Click to expand...

Neither of the chargers you listed show their maximum input current, just the voltage. I'd have to guess that it would PROBABLY work, but I don't know for sure. The one I posted earlier would work for sure, as it has the same output rating as most cigarette lighters and power points.
 
Zmanbaseball2

Zmanbaseball2

macrumors 68040
Original poster
Aug 24, 2012
3,542
11
New York, USA
Looking for an AC to DC power converter for USB car chargers

ElectronGuru said:
Why not cut out the middle man?:

PowerGen White 4.2-Amp (20 Watt) Dual USB Wall Charger Designed for Apple iPad & iPhone
http://amzn.com/B00BNQTIRQ

Search for "USB amp" brings up a ton
Click to expand...


I need an ac to dc for reviewing car chargers. I review many car chargers on amazon and it is winter and too cold to go test it in the car and is more roomy to plug in in a house.

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upa7ezuh.jpg
 
A

andyw715

macrumors 68000
Oct 25, 2013
1,753
1,357
T5BRICK said:
Both of the chargers that the OP posted have 12-24v listed as their input voltage. I don't think they'll operate correctly at 5v.
Click to expand...

Basically there are 2 conversions going on.

110ac to 12v dc (6A) - linked amazon item
then the car chargers
12v dc to 5vdc (usb) - with variable current draw ~8A each charger @ 5vdc

The draw on the chargers from the devices is 5v (USB charging.)
The converter I linked is 6A @ 12V (output)
6*12 = 72W

The first one listed is 2.4A x 4 ports @5v
so 2.4*4*5 = 48W

The second on listed is 8A (4 ports combined) @5V
so 8*5 = 40W


It won't be able to handle both chargers at full capacity though.
48W+40W = 84W
But I didn't see that requirement in the OP
 
E

ElectronGuru

macrumors 68000
Sep 5, 2013
1,656
489
Oregon, USA
Zmanbaseball2 said:
I need an ac to dc for reviewing car chargers. I review many car chargers on amazon and it is winter and too cold to go test it in the car and is more roomy to plug in in a house.
Click to expand...

Yours is the second reference I've seen in a month to 'professional amazon reviewer'. Silly me, I've been doing it for free!
 
T5BRICK

T5BRICK

macrumors G3
Aug 3, 2006
8,312
2,385
Oregon
andyw715 said:
Basically there are 2 conversions going on.

110ac to 12v dc (6A) - linked amazon item
then the car chargers
12v dc to 5vdc (usb) - with variable current draw ~8A each charger @ 5vdc

The draw on the chargers from the devices is 5v (USB charging.)
The converter I linked is 6A @ 12V (output)
6*12 = 72W

The first one listed is 2.4A x 4 ports @5v
so 2.4*4*5 = 48W

The second on listed is 8A (4 ports combined) @5V
so 8*5 = 40W


It won't be able to handle both chargers at full capacity though.
48W+40W = 84W
But I didn't see that requirement in the OP
Click to expand...

I can guarantee that the devices aren't 100% efficient though. The big unknown is the current draw of the two chargers themselves, but they don't list that information.
 
A

andyw715

macrumors 68000
Oct 25, 2013
1,753
1,357
T5BRICK said:
I can guarantee that the devices aren't 100% efficient though. The big unknown is the current draw of the two chargers themselves, but they don't list that information.
Click to expand...

Yeah I'm sure the chargers themselves draw (vampire) power.
But I would think that would be negligible in this case.

i.e. both can provide 8-9A at 5V to the devices.
so 40-50W.

To the converter that is 4A @ 12V
The converter can provide 6A
I doubt the charger has a 1-2A vampire draw (vampire draw is power used by the charger when its "idle")

There is plenty to spare.
 
A

andyw715

macrumors 68000
Oct 25, 2013
1,753
1,357
T5BRICK said:
Yes. Normally a device will list the input voltage and current as well as the output voltage and current. These don't list the input current, but they do list everything else.
Click to expand...

They probably don't cause at idle (non charging) its minimal current draw (i.e. light up a LED or something).
 
T5BRICK

T5BRICK

macrumors G3
Aug 3, 2006
8,312
2,385
Oregon
andyw715 said:
Yeah I'm sure the chargers themselves draw (vampire) power.
But I would think that would be negligible in this case.

i.e. both can provide 8-9A at 5V to the devices.
so 40-50W.

To the converter that is 4A @ 12V
The converter can provide 6A
I doubt the charger has a 1-2A vampire draw (vampire draw is power used by the charger when its "idle")

There is plenty to spare.
Click to expand...

I have a 120vac, 8w to 24v dc, 4w adapter at my workstation right now. This unit obviously isn't the most efficient piece of equipment ever(it loses 50% of the input power in the conversion from AC to DC), but keep in mind that converting from AC to DC is typically more efficient than converting from DC to AC.
 
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