Lumia 640XL wireless charging works！

[Yang Hu]

From the website we know that Lumia 640XL support wireless charging. In order to achieve that you just need to add a appropriate wireless charge receiver.
There are 4 contacts on the back of Lumia 640XL used for wireless charging which are GND, chager, WC_EN, WC_DET as shown in the picture below:

Coincidentally, there are also 4 metallic contacts on Lumia 920 used for wireless charging as shown in the pictures below:


So I made a attempt to connect them after studying the service schematics of Lumia 640XL and Lumia920. As a result, the wireless charging works successfully. :evil:



The correct connection scheme is below：


ATTENTION!!!
Although the wireless charging is working and the back cover can be closed, the wireless charging process is intermittent because of the receiver and back cover are a little thick. So still hope microsoft can drop the official back cover with wireless charging soon!

 

[perpleSlerp]

I saw that the other day, but to be honest.. the big deal about wireless charging escapes me. Plugging a phone in takes 2 seconds, plus you can pickup and USE the phone when it's physically plugged in. Also the charging pad is just another redundant expense. Of course just because I don't "get it" doesn't mean anyone else has to agree with me, but for me wireless charging is right up there with an IR Blaster on my lists of wants in my smart phone.

 

[blindguy]

Thank you Yang HU for figuring this out! I just upgraded form a 920 to 640 XL and I'm missing the Qi charging. I have already removed the TDK charging unit from the old 920. Just need to hook it up the 640 XL now.

 

[neodk]

Let's be fair, though, sometimes people miss when plugging in their phone to charge. When I had an iPhone 5S and 6, missing the port sometimes resulted in unwanted damage to the device. (Is there such a thing as wanted damaged?) Any further wear you can avoid putting your phone through is a good thing, albeit the cost of ownership needs to be just right. If and when an official solution is released and isn't priced higher than the cost of getting a Lumia 640 Go Phone, I may consider it.

 

[HoosierDaddy]

Let's be fair, though, sometimes people miss when plugging in their phone to charge. When I had an iPhone 5S and 6, missing the port sometimes resulted in unwanted damage to the device. (Is there such a thing as wanted damaged?) Any further wear you can avoid putting your phone through is a good thing, albeit the cost of ownership needs to be just right. If and when an official solution is released and isn't priced higher than the cost of getting a Lumia 640 Go Phone, I may consider it.

That's was my thinking. I bought a wireless charger just to save wear and tear on the USB port despite the fact wireless charging kept you from using the phone while charging. But wireless charging definitely made the phone hotter while charging than conventional charging. So I returned the wireless charger. I believe the heat would shorten the life of phone components more than the odds careful use of the USB port would ever damage it. I confirmed with other chargers that it wasn't a problem with the charger I had bought.

Lets hope the reason MS dropped the wireless charging in the 640XL was cost savings rather than because they didn't like how much heat it subjected components to.

 

[3earnhardt3]

That's was my thinking. I bought a wireless charger just to save wear and tear on the USB port despite the fact wireless charging kept you from using the phone while charging. But wireless charging definitely made the phone hotter while charging than conventional charging. So I returned the wireless charger. I believe the heat would shorten the life of phone components more than the odds careful use of the USB port would ever damage it. I confirmed with other chargers that it wasn't a problem with the charger I had bought.

Lets hope the reason MS dropped the wireless charging in the 640XL was cost savings rather than because they didn't like how much heat it subjected components to.

Heat was only an issue in the early days of Qi, new flexible printed circuit (FPC) Qi does NOT produce significant heat. My Ativ SE doesn't even get warm to the touch with the FPC module in. I also had a 928 for two years that sat on a Qi charger every night and never had any problems resulting from the heat produced.

 

[HoosierDaddy]

Heat was only an issue in the early days of Qi, new flexible printed circuit (FPC) Qi does NOT produce significant heat. My Ativ SE doesn't even get warm to the touch with the FPC module in. I also had a 928 for two years that sat on a Qi charger every night and never had any problems resulting from the heat produced.

Well my Lumia is a newer model than the 928 and got uncomfortably hot while wirelessly charging. I think you are missing the point when you mention you didn't have any problems from the heat. Obviously, a manufacturer isn't going to include wireless charging if they think it will cause enough problems to hurt profits. But they could probably care less if the phones still last thru the warranty period.

 

[netmann]

Yang,

Thanks for the DIY. Can you post the picture of the final product?......fitting the wireless charging coil on the inside face of the back cover of the phone.

Thanks

 

[GelatinousSlime]

Any idea what the WC_EN and WC_DET pins are for? I'm going to guess some kind of detection and enable functionality? I don't have access to an old 920 receiver unit and most of the receivers I can find only have the power and ground pins.

The 640 XL is my first Windows phone. I'm coming from my old Nexus 4 and am very used to having Qi charging so I was excited when I saw this post.

 

[Jackalneck]

Well my Lumia is a newer model than the 928 and got uncomfortably hot while wirelessly charging. I think you are missing the point when you mention you didn't have any problems from the heat. Obviously, a manufacturer isn't going to include wireless charging if they think it will cause enough problems to hurt profits. But they could probably care less if the phones still last thru the warranty period.

I've been wirelessly charging my 920 since the day it came out and have never had a problem. Same with my 1020 with wireless charging shell, and more recently my wife's 830. No, the fact that the phone warms up when charging has never been or never will be a problem on any Qi enabled device, you're really being paranoid if you think Qi is going to melt your phone, it's just completely unfounded and you really shouldn't be scaring people without hard facts to back up your crazy theory that Qi shortens phone lifespan some how.

 

[GG002]

Well my Lumia is a newer model than the 928 and got uncomfortably hot while wirelessly charging. I think you are missing the point when you mention you didn't have any problems from the heat. Obviously, a manufacturer isn't going to include wireless charging if they think it will cause enough problems to hurt profits. But they could probably care less if the phones still last thru the warranty period.

These devices get MUCH hotter when they're actually in intensive use than they ever get when on the Qi charger, so you're saying you can't actually use your phone because it gets "uncomfortably hot" and therefore will melt itself.

 

[netmann]

I saw that the other day, but to be honest.. the big deal about wireless charging escapes me. Plugging a phone in takes 2 seconds, plus you can pickup and USE the phone when it's physically plugged in. Also the charging pad is just another redundant expense. Of course just because I don't "get it" doesn't mean anyone else has to agree with me, but for me wireless charging is right up there with an IR Blaster on my lists of wants in my smart phone.

I agree with you on the plate charger. However, I bought the cradle charger when I got my L920. Absolutely no heat or other issues.....It actually charges faster than a wired connection....The cradle sits upright taking little space right in front of me on my desk below my desktop monitor ....so I can see who is calling, messaging, emailing, etc. I can operate the phone One-handed while it is being charged on the cradle. I can pick it up and put it right back in with ease...lots of conveniences...A good convenience is when you are updating your phone which takes a long time and seeing every step of the way right in front of you hands free while you can do other things. Heck, I can even use the cradle as an upright holder for my L640!

 

[Eas195]

Wow... I didn't think about that 4 contacts in the back of the phone that are required for wireless charging... good catch, mate!
What I did see there is we can use that contact to make the Qi wireless charging-enabled back case for Lumia 640XL (I saw the real picture that it really exposes the 4 contacts), which is pretty good for making it wirelessly charged without doing the hack anymore. Anybody?

 

[Exhibit13]

now I might buy a new 640xl and a broken 920 off ebay to upgrade from my 925 till the 950 arrives in October!

 

[Yang Hu]

Although the wireless charging is working and the back cover can be closed, the wireless charging process is intermittent because of the receiver and back cover are a little thick. So still hope microsoft can drop the official back cover with wireless charging soon!

 

[Derausgewanderte]

Although the wireless charging is working and the back cover can be closed, the wireless charging process is intermittent because of the receiver and back cover are a little thick. So still hope microsoft can drop the official back cover with wireless charging soon!

you can purchase some thin ferrite tape online which may help with the induction process if there is too much space between the coil and the charger. Has worked on my L830 with a thick case. You can purchase from here.(I did not purchase there, got mine from work).
EMI Tape offers ferrite sheet ? NFC World+

Would be great to find a flat ribbon cable instead of the wires. Something similar to this that can be folded. Will do some digging at work.

 

[Edward IV]

So I tried to recreate this hack to give my 640 XL some Qi charging without having to occupy the USB port. However after soldering some wires onto the receiver, in my haste and in a bout of sleep deprivation, I accidentally connected the wires to the pads on the phone backwards and applied power to the receiver before realizing my folly. I believe I had connected the VOUT on the receiver to the WC_EN on the phone which means I may have sent about 7V and up to 1A of electricity to somewhere it shouldn't have gone. That must have done something awful because, to my dismay, the phone would not charge after everything was wired correctly. Using my old 920, I was able to determine that the receiver was working so I must have broken the phone. Fortunately, everything else besides the wireless charging hookup is working for now.

So is there anything I can do short of getting a new 640? I took a look at the mainboard and didn't notice any noticeable damage. On the other hand, a lot of stuff was under shielding so I have my doubts on being able to repair any hardware.

 

[Loki1973]

Recently my 1520 crashed to the ground breaking the glass. I was not insured for that kind of damage, so I bought the Lumia 640XL until a new flagship comes along. However I instantly missed the wireless charging as I have the DT920 throughout the house and office and the CR201 in both my car and my wife's.

My wife recently replaced her 920 with a 930. The 920 is still working fine, so I am very reluctant to open it up and get the Qi charger out. I want to save it as a spare.

Digging around I also found an 820 with wireless charging shell. That phone's glass was also broken, so no loss there. I've been peeling of the plate and antenna from the shell and it seems to have come loose very easy and undamaged.

If this plate would work, you could just get an 820 charging shell and peel out the plate and antenna and hook it up to the 640XL.

I've been trying to get it to work on the Lumia 640XL, as it also has the four contacts. But so far, no luck. Without any contacts connected, the charging light of the DT900 lights up, so the plate itself seems get a power feed.

However I'm unable to find documentation about the innards of this Qi charger, and as such been unable to determine which contact does what. Does anyone here have any suggestions?

Edit: Something else I noticed, is that if you put the 640XL into the CR-201, the charging LED on the carkit starts flashing, so it definitely seems some internal circuitry is being detected, even without any plate connected.

 

[Derausgewanderte]

Edit: Something else I noticed, is that if you put the 640XL into the CR-201, the charging LED on the carkit starts flashing, so it definitely seems some internal circuitry is being detected, even without any plate connected.

that could be simply NFC connection between phone and device. A number of chargers have that built in.

 

[Derausgewanderte]

BTW. I am still looking for a flex flat ribbon cable with 4 pins. This comes close but the pitch is only 1mm. I measured the pitch of the 640XL connections to be 3mm. Maybe one can splice the 1mm pitch flex cable or use a 12 pin cable and only use every 3rd lead. Then slide the exposed ends into/under the sprinloaded 640XL connectors and tape them down to secure them and avoid soldering to the phone. Then fold the cable to be able to solder the other end to the L920 coil or alternative charging receiver (I am looking at one from a L830). If I can't find a wider pitch one I will give this a try soon.
cheers