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What 3rd party wireless charger will you get? [MERGED]

Went through the thread (all 39 pages! :)) but couldn't find a response on this.
Has anybody found a 3rd party Qi charger working at a distance of about an inch? It is certainly technically possible (the standard allows up to 1.6 inches) but could not find anywhere a charger capable of such distance. I'm not very interested in performance as I leave my :apple: on the stand overnight (but plan to install it inside a bedside)
 
kiristu said:
Went through the thread (all 39 pages! :)) but couldn't find a response on this.
Has anybody found a 3rd party Qi charger working at a distance of about an inch? It is certainly technically possible (the standard allows up to 1.6 inches) but could not find anywhere a charger capable of such distance. I'm not very interested in performance as I leave my :apple: on the stand overnight (but plan to install it inside a bedside)
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Anyone?
 
kiristu said:
Anyone?
Click to expand...

If I’m not mistaken, energy loss is exponential to the distance it needs to travel in inductive charging.

In order to travel 1.6”, the amount of energy radiation of the charger would need to be significant and likely dangerous. If you add in some other material, like wood, that energy loss will be compounded further.

I could be wrong about this and perhaps an electrical engineer can jump in to comment on the physics of wireless energy transfer, but I think I’m in the ballpark.

As I sit here writing this reply, next to my bedside table where I keep my wireless charging pad, I thought I’d look under my table, to see just how thick the top is, with the idea of putting the charging pad below and being able to just set my X down on the wood for a completely wireless look. But even with the ¼” thick wood top, it’s almost impossible to get the phone to charge.

I love the idea and may try to router away some of the wood under the top to see if I can get it to work better. Would love to be able to just set my phone down and have it “magically” charge.
 
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jmgregory1 said:
If I’m not mistaken, energy loss is exponential to the distance it needs to travel in inductive charging.
Click to expand...
You're absolutely spot on, but I don't need this charger to be fast, as I would only use it overnight.

jmgregory1 said:
In order to travel 1.6”, the amount of energy radiation of the charger would need to be significant and likely dangerous. If you add in some other material, like wood, that energy loss will be compounded further.
Click to expand...
On the Qi standards, §4.3 states: "The power transfer system in the Power Class 0 specification is based on a [...]receiver that has an outer diameter of 40 mm (1.6 in)."
Also, Wikipedia defines Qi as "an open interface standard that defines wireless power transfer using inductive charging over distances of up to 4 cm (1.6 inches)"

So to twist my original question - if the standard was designed to allow charging over distances of up to 4 cm, why can't I find any on the market which actually does?
 
kiristu said:
You're absolutely spot on, but I don't need this charger to be fast, as I would only use it overnight.


On the Qi standards, §4.3 states: "The power transfer system in the Power Class 0 specification is based on a [...]receiver that has an outer diameter of 40 mm (1.6 in)."
Also, Wikipedia defines Qi as "an open interface standard that defines wireless power transfer using inductive charging over distances of up to 4 cm (1.6 inches)"

So to twist my original question - if the standard was designed to allow charging over distances of up to 4 cm, why can't I find any on the market which actually does?
Click to expand...

It's complicated by what I noted, energy loss over distance. You'd need far more power to effectively transmit across a 1.6" distance, or some way to focus the magnetic radiation in order to minimize loss/maximize efficiency. If I remember correctly, when you get past a 5mm-7mm distance, the efficiency of energy transfer falls off precipitously. And just adding more power on the transmitter side doesn't work, because the receiving coil needs to be tuned to the same frequency.

I'm sure someone could test the actual difference in energy transfer over varied distances by setting up a rig using an iPhone and a charging pad. You could have the phone held .25", .5", .75" and so forth away from the charging pad, then test to see both what the maximum height is you can still get the charger to connect to the iPhone as well as how long it takes to charge at the various heights and the amount of heat generated. I assume that the Qi group members have done this countless times and there is a reason why they all seem to suggest minimizing the distance between charger and device to something in the less than 5mm range.
 
ZipZap said:
That is a $30 stand with no power adapter. I am sure there are other stands that are cheaper and will work with a fast charge adapter. I have seen some with fans as the fast charging heats up the device.
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I have this Qi stand and I bought it for $16.99 in November. I use it with an iPad 10w charger and I do not get 7.5w. I’m not sure what charger they say you can use that will get you 7.5w. Doesn’t matter to me because it’s my nightstand charger and works perfectly fine for that.
 
cydeweyz said:
It’s the exact same stand, but different seller. I posted about the two I bought months ago. Check my posts.
0113905bfae4ce7666bc421441b4df73.jpg
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Found it for $13.01
 
ZipZap said:
No idea, it charges an iPhone X and appears to have all the same features.
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Looking at a lot of these Qi chargers on Amazon they appear that one style is made by a wholesale manufacturer, then bought up and sold by different resellers for different prices.
 
cydeweyz said:
Looking at a lot of these Qi chargers on Amazon they appear that one style is made by a wholesale manufacturer, then bought up and sold by different resellers for different prices.
Click to expand...

I agree. I have the $13.01 version. Works great.
 
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