[boltman2013]

Don't do it will kill the battery

[Derausgewanderte]

Normal. Either that or we both have bum units

normal, just did this on my 640XL and get the message as well. Too bad it's difficult to unplug it temporarily for PC connection. Otherwise it works great so far. PS: Here is the one with the right configuration on Amazon.

edit: actually, charging is very slow on mine and it gets pretty warm. I am not sure if I will continue this. Good to know it's an option. I may try this again later.

the output of the receiver is DC5V/1000mA Max. That should be fine and not give a slow charge warning if it was an actual 1A. I believe that the distance from the charging coil to the charger is too large and it's much less than 1A that the battery will get - hence the slow charge warning.

edit2: I am getting better behavior and less heating on the Nokia DT-900 charger compared to the Energizer charger I tried previously.

[Derausgewanderte]

Don't do it will kill the battery

can you elaborate? Your conclusion sounds important enough to get more details. Did you try this yourself or saw this posted somewhere?
thanks

[boltman2013]

can you elaborate? Your conclusion sounds important enough to get more details. Did you try this yourself or saw this posted somewhere?
thanks

How To Take Care of Your Smartphone Battery the Right Way
Avoid wireless charging

"Wireless charging can be incredibly convenient if your phone can do it, but it's not without its disadvantages. The inductive, wireless chargers out there today have this nasty habit of generating a fair bit of waste heat. And while wasted energy is just a bummer in general, that heat will also toast your battery in the process. That's no bueno. It's a little less convenient, but standard plug-in charging is going to keep your battery in better shape, especially if you're some place warm to begin with."

Other pointers charge before it drops below 20% and charge to about 80% (work the middle not the ends when possible)
Once a month do full discharge
Keep cool

[Derausgewanderte]

thanks, I do understand the science behind this. The heating problem is an annoyance. But convenience is great too. As the article reads, it's a trade off.
As for heat shorting the battery life, without any data on how much the life is reduced at temps of 40C at charging intervals it's very vague. The article also reads that faster charging is bad to battery life. We know that with wireless charging the process at least on the 640XL with the posted receiver is slower. In theory that should be better for the battery, maybe even cancelling out the negative effects of heat.

I'm just making simple assumptions just like the article does. Unless we do a test this is all speculation I believe. If it reduced the life of the battery by 10% that's fine with me...

thanks for the links
cheers

[willgill]

The small distance between the induction coils has a lot to do it efficiency and thus heat. I have several wireless charging pads, Energizer dual pad, two Nokias, two TYLT stands, four car holders with built in changing and several generic QI chargers.



Look for charging pads with three coils. It makes the sweet spot larger and charging more efficient.



Don't use a thick case. Every millimeter means more distance and more heat. My daughters Galaxy S5 has a thick case and gets crazy hot. My old Galaxy had no case and barely got warm.



And don't ever completely discharge any Lithium ion or lithium polymer battery. Run that mid band for ultimate life.

[zilchspam]

Anyone ever seen a microUSB pass through connector or is it something that is just not possible. This sort of add on project would be better if you could have the wireless charging unit hidden inside the battery area plugged into your microUSB but also still use the microUSB for connecting to your computer without having to unplug the wireless charging unit.

[Will Gilliland]

Anyone ever seen a microUSB pass through connector or is it something that is just not possible. This sort of add on project would be better if you could have the wireless charging unit hidden inside the battery area plugged into your microUSB but also still use the microUSB for connecting to your computer without having to unplug the wireless charging unit.

I've never seen a pass-through, but I was concerned about the wireless-only charging. I wanted the option to charge it via USB cable. I just left a small loop outside the batter cover to allow me to pop the plug when needed.
The phone does get a bit warm on my 3-coil TYLT charger. My Samsung GS4 doesn't get nearly as warm. I'll see if I can get some temp readings with an IR thermometer.

[Papek_SVK]

I just added wireless charging to my 640 LTE. It requires torx screwdriver, soldering skills and little patience. See pictures below.


Universal wireless charger module, $3.30 on ebay.




Remove battery cover, battery, SIM card, microSD and screws as shown in the picture. There is one screw under the sticker and two screws on the side.




Carefully lift the back part from the right side. and disconnect two flex cables.




Disconnect camera and audio jack cable on the back part and remove PCB. PCB is held by plastic hooks, so be carefull and don't broke them.




There are four contacts, which are galvanically connected to the USB pins. I soldered very thin wires from old USB cable. Be quick and don't overheat the board. Carefully remove any excess flux.




Now you need to modify the module. Open the module and unsolder flex cable.




Assembly the phone. Guide the wires through the gap under removed sticker in the back cover and solder them to the charging module. I was little careless and touched the label with solder tip so I cut it away and covered it with black insulating tape.





It works! Keep in mind this mod ruins your warranty!

[Will Gilliland]

I just added wireless charging to my 640 LTE. It requires torx screwdriver, soldering skills and little patience. See pictures below.

That is some fantastic work! I may just do the same thing for my 640. I don't care about the warranty, but I do have a concern.
When I plugged this module into the bottom USB as it was intended, I thought the heat was excessive. I used an IR surface thermometer to test the surface temps of both my Galaxy S4 with wireless charging cover and my 640 with this adapter. I tested the top, middle and bottom sections of both front and back on both phones. Here are my readings, all in degrees F.

Galaxy S4
Front Top 87
Front Middle 86
Front Bottom 86
Back Top 86
Back Middle 86
Back Bottom 85

Lumia 640 with wireless adapter
Front Top 91
Front Middle 94.8
Front Bottom 94.3
Back Top 92
Back Middle 100.7
Back Bottom 97

Both phones were left on the charger fully charged. I don't think the difference is in the efficiency of the wireless charge. I just think the mod feeding into the USB can't regulate the input and must dissipate it within the addon module's circuitry.

I'm VERY curious if soldering onto the battery pins cures this issue. If it does, I have a new weekend project. Let me know how hot your 640XL is getting with this mod.

Also, is there any reason why you just didn't solder onto the battery lugs in battery compartment? Was there not enough room left after you inserted the battery to attach wires?

[Papek_SVK]

I'm glad you like my work. Neither I don't care about the warranty since I bought this phone in the US but I live in Europe. I'd buy new one than sending it to RMA. $60 is really nothing compared to €170 here in EU.

I didn't measured the temperature but it didn't seem to be much hotter than when charging via cable. My Lumia 950 gets really hot compared to this 640 during charging but I don't have IR thermometer. I can try measure it with a multimeter with a thermal probe.

I decided to solder it to USB pins and not any further in power circuit to eliminate potential problems and risks. I tested this charging module by connecting it to USB. It charged my 640 during a night and everything was ok.
I wouldn't solder it to battery pins since the battery is only 3.7 V and output from the module is 5V.

Edit: my friend likes this upgrade and wants it too :D I'll try to make it neater this time. I'll keep flat cable with wireless module and solder it to USB pins with rework station. If it won't work (since flat cables aren't friends with soldering irons), I'll drill small hole next to battery contacts and will guide the wires through it, so It will be covered with module and practically invisible.

[Will Gilliland]

Please take pictures of this new project. I'm hoping to attempt this mod before the end of the year.

[Papek_SVK]

I don't expect shipment with coil in this month. I have ordered multiple gadgets from China in November and many of them didn't arrived yet.

[lachutm]

Those four pins under SIM slot looks like those on 640XL. They are hidden under black sticker
http://forums.windowscentral.com/mic...ia-640-xl.html

[netmann]

I just added wireless charging to my 640 LTE. It requires torx screwdriver, soldering skills and little patience.

Thanks for this DIY...I was thinking of adding wireless charging to my 640 DS. Can you share what size Torx screwdriver you used? Also, did you get a chance to measure the charging time of a complete depleted battery to 100% charged status using only the wireless charging?

Thanks

[Derausgewanderte]

Those four pins under SIM slot looks like those on 640XL. They are hidden under black sticker
http://forums.windowscentral.com/mic...ia-640-xl.html

here are instructions on how to solder the qi receiver from the L920 to the 640XL. The 4 pins are actually open and not hidden when you take the cover off.

[Papek_SVK]

Thanks for this DIY...I was thinking of adding wireless charging to my 640 DS. Can you share what size Torx screwdriver you used? Also, did you get a chance to measure the charging time of a complete depleted battery to 100% charged status using only the wireless charging?

Thanks

Now I'm using Lumia 950 DS so I can't tell. L950 uses T5, they should be on 640 too. I gave L640 to my mom since she had outdated Lumia 800.
I didn't test how long take to fully charge battery but I remember it was charging around 20% a hour. +/- 5 hour sounds real. I'm charging my phone overnight and anytime at work when lying on the table so I don't have to worry about battery when I go out.

[netmann]

Now I'm using Lumia 950 DS so I can't tell. L950 uses T5, they should be on 640 too. I gave L640 to my mom since she had outdated Lumia 800.
I didn't test how long take to fully charge battery but I remember it was charging around 20% a hour. +/- 5 hour sounds real. I'm charging my phone overnight and anytime at work when lying on the table so I don't have to worry about battery when I go out.

Thanks. I also have Lumia 920 and looking at the picture of the wireless coil module on the back of the plastic housing, it is sitting in the location that makes the entire coil in contact with the battery, and in turn in perfect contact with my upright wireless charger cradle (Nokia DT-90). So one reason for long charging time could be because the eBay wireless coil module is not entirely in contact with the battery. I also have the following questions:

1) How did you find out the +5v and Ground terminals on the galvanic contacts of the USB Pins?
2) There are four (4) galvanic terminals. Do you know what the other two are?
3) I searched internet for the Lumia 640 Schematics diagrams but I could not find them. Do you happen to find a valid and downloadable link that you can share? Having that would answer my first two questions.
4) What size wiring between the coil and terminals is the best for this mod? I imagine it would be something with low resistivity and high conductivity.

Thanks

[Derausgewanderte]

Thanks. I also have Lumia 920 and looking at the picture of the wireless coil module on the back of the plastic housing, it is sitting in the location that makes the entire coil in contact with the battery,

I don't think the receiver coil touching the battery makes any difference. If it does something then it is heating of the battery. The coil produces charge that it transferred wired to the battery, not via induction. The latter only happens between the coil and your qi charger.
Cheers

[Papek_SVK]

Thanks. I also have Lumia 920 and looking at the picture of the wireless coil module on the back of the plastic housing, it is sitting in the location that makes the entire coil in contact with the battery, and in turn in perfect contact with my upright wireless charger cradle (Nokia DT-90). So one reason for long charging time could be because the eBay wireless coil module is not entirely in contact with the battery. I also have the following questions:

1) How did you find out the +5v and Ground terminals on the galvanic contacts of the USB Pins?
2) There are four (4) galvanic terminals. Do you know what the other two are?
3) I searched internet for the Lumia 640 Schematics diagrams but I could not find them. Do you happen to find a valid and downloadable link that you can share? Having that would answer my first two questions.
4) What size wiring between the coil and terminals is the best for this mod? I imagine it would be something with low resistivity and high conductivity.

Thanks

I don't think that speed of charging has anything with distance to a battery. Maybe coil quality, electronics ... I had Lumia 920 and 928 but I really don't remember how fast or slow was wireless charging. Keep in mind that Lumia 920 has 2000 mAh battery, while 640 has 2500. Thats 25% more which should lead to slower charging.

1) multimeter and micro USB cable with open end. I could find there is no diode or anything in the path between pins and contacts
2) rest are data pins
3) I wasnt looking for them
4) as short as possible. I used wires from old USB cable. They are very thin and flexible but works fine for charging.

[vicu9mx]

Once a month do full discharge

Really?? Do you take only the part that say avoid wireless charging and not this part??

Never go to zero

If you're going to be shelving any lithium-ion battery for a long time, try to leave it with at least 40 percent battery power to tide it over. Lithium-ion batteries don't hemorrhage power when their not in use, but they'll lose maybe five to ten percent of their charge each month.
And when lithium-ion batteries get too low—like, literally zero percent—they get seriously unstable, and dangerous to charge. To prevent explosion-type disasters when you go to charge one that's been sitting around for a month or two, lithium-ion batteries have built-in self-destruct circuits that will disable (read: destroy) the battery for good, if it reaches rock bottom. And sure, that'll save you from a face full of battery-acid, but it'll also leave you short one battery.

[Will Gilliland]

... I thought the heat was excessive. ... I tested the top, middle and bottom sections of both front and back on both phones. Here are my readings, all in degrees F.

Galaxy S4
Back Middle 86

Lumia 640 with wireless adapter
Back Middle 100.7
?

My Qi universal receiver tag finally quit working. I order a new one and it's working MUCH better. The back still gets pretty warm, but I wouldn't call it "hot" like my first tag. Folks, I think I just received a bad one the first time. Now I'm much more encouraged to do this mod.

[Matej25]

I just added wireless charging to my 640 LTE. It requires torx screwdriver, soldering skills and little patience. See pictures below.


Universal wireless charger module, $3.30 on ebay.




Remove battery cover, battery, SIM card, microSD and screws as shown in the picture. There is one screw under the sticker and two screws on the side.




Carefully lift the back part from the right side. and disconnect two flex cables.




Disconnect camera and audio jack cable on the back part and remove PCB. PCB is held by plastic hooks, so be carefull and don't broke them.




There are four contacts, which are galvanically connected to the USB pins. I soldered very thin wires from old USB cable. Be quick and don't overheat the board. Carefully remove any excess flux.




Now you need to modify the module. Open the module and unsolder flex cable.




Assembly the phone. Guide the wires through the gap under removed sticker in the back cover and solder them to the charging module. I was little careless and touched the label with solder tip so I cut it away and covered it with black insulating tape.





It works! Keep in mind this mod ruins your warranty!

Super robota chlape ;)

Nice job buddy ;)

Anyway, I have just studied mine 640 LTE and there is preparation for the wireless charging see my picture below.
Under that black sticker there are 4 holes for the wireless receiver connection and on your picture of PCB on the same place there are 4 contacts which should be connected to USB port (not 100% sure, this needs to be checked).
So there should be option to create back case like the one which 830 has, with the wireless charging receiver included.

[fangio2]

Hello,

I also check my L640 to install the wirless charging (the qi pad from L920).
I found also the 4 pins under the sticker.
Have anybody the service schematic for this Lumia?
Is it similar to the pins at the L640 XL?

[susanne1188]

hi i have ever tried out the assignment of the pins . I do not know whether it is right and can not even try ... no lumia phone (but next week :D) about the GND i even havent find in the schematic some about, but should be right. sry bad englisch (mother tongue german) maybe some one try it out or can add / rectify a bit...
SECOND PIC IS FROM 640XL!!!! (wc11.jpg)