DC outlet for USB charging
#1
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DC outlet for USB charging
Hello All,
This is my first post on this site.
I have a question and I hope I don't come across as being stupid.
Background
I have a DC system 12V (5Amp max)solar system. It has a 10W panel, and I am using a LFP battery for storage. I am using a suitable LFP charge controller which has a 5A max output also. So i think I have matched the battery, charge controller and solar module as required.
I want to use this small solar system to charge a iphone or tablet device using a USB 5VDC wall socket.
My question(s) is/are..
Do I use a simple 12VDC to 5VDC stepdown cable/unit like the image attached?
When I plug in the device to the USB socket what is stopping the device from overcharging in relation to the current draw?
i.e. does the device only "draw" the current it needs (@5V) or do i have to protect it from the controller if it is "pushing" 5A max (@5V) to it? My understanding is that the iphone and tablets like 2A for charging?
Any advice is much appreciated. I don't want to blow up my devices.
This is my first post on this site.

I have a question and I hope I don't come across as being stupid.
Background
I have a DC system 12V (5Amp max)solar system. It has a 10W panel, and I am using a LFP battery for storage. I am using a suitable LFP charge controller which has a 5A max output also. So i think I have matched the battery, charge controller and solar module as required.
I want to use this small solar system to charge a iphone or tablet device using a USB 5VDC wall socket.
My question(s) is/are..
Do I use a simple 12VDC to 5VDC stepdown cable/unit like the image attached?
When I plug in the device to the USB socket what is stopping the device from overcharging in relation to the current draw?
i.e. does the device only "draw" the current it needs (@5V) or do i have to protect it from the controller if it is "pushing" 5A max (@5V) to it? My understanding is that the iphone and tablets like 2A for charging?
Any advice is much appreciated. I don't want to blow up my devices.
#3
You are not coming across as stupid and have a valid point.
I'm an electronics tech but not an authority on Apple products. Technically, you should be able to connect your devices to a 5vdc 5amp source and they should charge normally as they have built in smart chargers.
However, I stopped over at the Apple forum and there was a 23 page thread running on this very subject. I've read it's ok to use a higher powered charger and I've read it hurts and reduces the life of the battery.
I would err on the side of caution and use a 2A maximum converter.
The thread..... in case you'd like to check it out.
discussions/apple/thread/2580579
I'm an electronics tech but not an authority on Apple products. Technically, you should be able to connect your devices to a 5vdc 5amp source and they should charge normally as they have built in smart chargers.
However, I stopped over at the Apple forum and there was a 23 page thread running on this very subject. I've read it's ok to use a higher powered charger and I've read it hurts and reduces the life of the battery.
I would err on the side of caution and use a 2A maximum converter.
The thread..... in case you'd like to check it out.
discussions/apple/thread/2580579
#4
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Hello,
I am not sure about the USB. I had a look at these two on alibaba site.
High Quality Usb 2.0 Wall Plate Supplier - Buy Usb 2.0 Wall Plate,High Quality Usb 2.0 Wall Plate,Usb 2.0 Wall Plate Supplier Product on Alibaba.com
or
Usb Wall Plate - Buy Usb Wall Plate,Usb Wall Plate,Usb Wall Jack Product on Alibaba.com
I am not sure about the USB. I had a look at these two on alibaba site.
High Quality Usb 2.0 Wall Plate Supplier - Buy Usb 2.0 Wall Plate,High Quality Usb 2.0 Wall Plate,Usb 2.0 Wall Plate Supplier Product on Alibaba.com
or
Usb Wall Plate - Buy Usb Wall Plate,Usb Wall Plate,Usb Wall Jack Product on Alibaba.com
#5
OK, thanks. I just wanted to be sure that you were looking at something that was USB only, not a combination fed by 120V AC, like a Leviton USB charger/tamper-resistant receptacle.
#6
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ok, Thanks PJMAx.
just to confirm...
From my charge controller that is rated at 5A max and 12V output, i need to connect this to a converter that steps it down to 2A max and 5V.
Is this 2A max 12V->5V a common cable or connector?
just to confirm...
From my charge controller that is rated at 5A max and 12V output, i need to connect this to a converter that steps it down to 2A max and 5V.
Is this 2A max 12V->5V a common cable or connector?
#8
I am avoiding those with 110/220V AC combined.
