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Ive had a simple idea of how to make a charger that can be left plugged in but once the phone is removed the charger disconnects from the mains until the phone is reconnected.
i would like the idea to be open to all manufactures to use for free as i think it would help the environment anybody got any ideas how to proceed maybe offer it to google?
Not sure what you mean by disconnects from the mains. Are you saying that it will not use any power?
I do not understand your idea, you can explain better?
If you leave a charger plugged into the mains with no phone connected, it still uses electricity which is a waste.
The OP's idea would be to have the charger break the mains circuit when a phone is not connected.
Sensible idea.
Off the top of my head, with an old transformer model, you'd have a mosfet to close the mains circuit when the 5v circuit is closed. To start it off you'd have a push to make switch in parellel to the mosfet.
So you connect the phone, push the start button, the mains circuit is completed energising the 5v circuit which activates the mosfet keeping the mains side closed.
When you disconnect the phone the 5v circuit is broken, the mosfet opens the mains side and power is totally cut.
Not opened a recent charger though but given their size I don't think they work like an old chunky transformer type.
This is done on several larger devices, all you are doing is creating a loop that recognizes load or no load, when no load is on, the shunt (elec gate) is in the open position, when it has load it creates a closed position allowing power to pass through. My guess is the cost verses benefit is not there to implement yet on such small elec demand devices. FYI even a plugged in extension cord will draw a micro amount of power, so the Zero use when not plugged in would not happen, but near zero is doable.
Good thinking on this........
I just switch the socket off
xaccers said:
I just switch the socket off
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Click to collapse
lol probrobly the simplest, easiest and best solution
My idea would be to have a small magnet on the back of the device to pull a relay in this would be isolated from the mains but act directly on the power circuit without additional power.
or make a flexible ferrite core not dissimilar to those rubber magnets to a cable and add it to a usb cable and do much the same thing.
EDIT: SCROLL DOWN TO POST #12 WHERE I SHOW YOU HOW TO BUILD YOUR OWN FULL-1900 mAh CHARGER!
http://forum.xda-developers.com/showpost.php?p=43663686&postcount=12
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Has anyone used this particular item before? Or can recommend a similar hard-wire unit that operates at 2A to 3A?
http://www.amazon.com/DROK-Converter-Connectors-Adapter-Recorder/dp/B00D6B6CJI
I'm thinking about getting one for my SUV and Motorcyle to charge the S4 at normal 1900 rates like the OEM wall-charger. Get that FAST charge.
Yes, I know about cig lighter chargers. No, that is not what this thread is for.
hello did you buy it?
CZ Eddie said:
Has anyone used this particular item before? Or can recommend a similar hard-wire unit that operates at 2A to 3A?
http://www.amazon.com/DROK-Converter-Connectors-Adapter-Recorder/dp/B00D6B6CJI
I'm thinking about getting one for my SUV and Motorcyle to charge the S4 at normal 1900 rates like the OEM wall-charger. Get that FAST charge.
Yes, I know about cig lighter chargers. No, that is not what this thread is for.
Click to expand...
Click to collapse
I have this hardwired into my WRX:
http://www.ebay.com/itm/CDL-WaterPr...35?pt=US_Power_Inverters_&hash=item1c34627e83
I ran it off the clock circuit (my clock is dead anyways) but any switched 12v source will do. It charges my car integrated Nexus7 without any issues, and at the faster rate.
I have another powering a servo and an aux USB port, but unfortunately I ran so much wire to get it into the center console by the handbrake it charges at USB rates.
paolopaulpaul said:
hello did you buy it?
Click to expand...
Click to collapse
Not yet.
Caferacer said:
I have this hardwired into my WRX:
http://www.ebay.com/itm/CDL-WaterPr...35?pt=US_Power_Inverters_&hash=item1c34627e83
Click to expand...
Click to collapse
Wow, that's a great price! Does it charge at ~1900 rates? Here is an app that will tell you the charging rate:
https://play.google.com/store/apps/details?id=ccc71.bmw&hl=en
Just bought this one for $9 shipped.
http://www.ebay.com/itm/NEW-waterpr...34?pt=US_Power_Inverters_&hash=item3a7a051922
It's a waterproof box so it'll be better on my Motorcycle. I'll let you guys know how it works out by next week sometime.
There was a thread somewhere that explained why some chargers won't do the 1900mah charge. He figured out where and what size resistors to put across the wires to enable it. I think it was in a car dock thread, I'll try and find it.
Sent from my de-Verizonized Galaxy S4, CleanRom style! (using Tapatalk beta 4)
CZ Eddie said:
Not yet.
Wow, that's a great price! Does it charge at ~1900 rates? Here is an app that will tell you the charging rate:
https://play.google.com/store/apps/details?id=ccc71.bmw&hl=en
Click to expand...
Click to collapse
That app won't show the mA on my N7 but does show it charging near the same % as a fast charger.
MonkeyTime said:
There was a thread somewhere that explained why some chargers won't do the 1900mah charge. He figured out where and what size resistors to put across the wires to enable it. I think it was in a car dock thread, I'll try and find it.
Sent from my de-Verizonized Galaxy S4, CleanRom style! (using Tapatalk beta 4)
Click to expand...
Click to collapse
It's the shorting/grounding of the data pins that activates 'fast charge' mode on some phones. Nexus 7's and my E4GT (Sprint S2) when I used it didn't require the pins to be shorted to charge faster. Mostly it was the charger (duh) and the quality/length of the cable that affected the charge speed. As well, most of the heavy 1A plus chargers short the data pins in the charger itself so you can use any cable. I believe the S4 doesn't require it as well, but don't have any data to confirm it.
The way I wired mine was to sacrifice a USB female port from a USB extender, and attached the power leads and shorted the data leads. Figured it couldn't hurt. The converter doesn't care if it's putting out 500mA or 3A. It's not intelligent like some chargers in what current it doles out.
Caferacer said:
shorted the data leads. Figured it couldn't hurt. The converter doesn't care if it's putting out 500mA or 3A. It's not intelligent like some chargers in what current it doles out.
Click to expand...
Click to collapse
Yours is the second post I've seen where someone has shorted the data pins on a charging-only setup. Is there a reason for doing that?
Ehh, n/m. I remembered the "Google before you ask" mantra...
This explains it nicely:
http://forums.androidcentral.com/samsung-galaxy-s3/194362-wont-charge-over-usb-car.html
MichaelBR said:
There are some reasons why it won't work, and some ways to solve it. First, let's understand how it works:
The USB cable has four pins. The inner two pins are where the data goes through. THe outer, power.
When the USB cable is plugged in to a computer, the data pins are connected normally and the phone knows it can only draw certain amount of power
When the cable is plugged in to a charger, the two middle pins are shorted, and the phone knows that it's NOT going to be sendind/receiving data, so it can draw as much power as it can. That's why it charges faster with the charger than when plugged in to a computer
Most chargers short the two pins. Some cables have a switch to do that.
There are different cable cauges as well, with different power capacities.
Some USB chargers, notably car chargers and some low-end (i.e. not good brand) chargers that don't draw from the car/don't give the phone as much current as it needs.
So, if any of below, the phone won't charge, or won't charge fast enough. Or, worse: it may appear as charging, but actually losing battery charge!
Cable too long or incorrect gauge
Middle pins not shorted for some reason
Charger doesn't deliver enough current
And the solutions are:
Don't use cable extensions, cables that are too long. Stick with the cable that came with the phone or with the charger
Get a good car charger, that delivers the right amount of current
I imagine you just got the cable from your original wall charger and plugged it in to the car charger. If you did that, then chances are the cable is OK, and the charger is the culprit. If this is the case, then get a better charger. Check how much current that charger can deliver. Check how much current your device actually needs.
Hope this helps.
Click to expand...
Click to collapse
CZ Eddie said:
Yours is the second post I've seen where someone has shorted the data pins on a charging-only setup. Is there a reason for doing that?
Ehh, n/m. I remembered the "Google before you ask" mantra...
This explains it nicely:
http://forums.androidcentral.com/samsung-galaxy-s3/194362-wont-charge-over-usb-car.html
Click to expand...
Click to collapse
To be clear, there is no indication it is *required* for the S4. Mine quick charges just fine without shorted data leads. However I did this because my friends have a variety of phones and it only took a few minutes to do.
Caferacer said:
That app won't show the mA on my N7 but does show it charging near the same % as a fast charger.
It's the shorting/grounding of the data pins that activates 'fast charge' mode on some phones. Nexus 7's and my E4GT (Sprint S2) when I used it didn't require the pins to be shorted to charge faster. Mostly it was the charger (duh) and the quality/length of the cable that affected the charge speed. As well, most of the heavy 1A plus chargers short the data pins in the charger itself so you can use any cable. I believe the S4 doesn't require it as well, but don't have any data to confirm it.
The way I wired mine was to sacrifice a USB female port from a USB extender, and attached the power leads and shorted the data leads. Figured it couldn't hurt. The converter doesn't care if it's putting out 500mA or 3A. It's not intelligent like some chargers in what current it doles out.
Click to expand...
Click to collapse
Caferacer said:
To be clear, there is no indication it is *required* for the S4. Mine quick charges just fine without shorted data leads. However I did this because my friends have a variety of phones and it only took a few minutes to do.
Click to expand...
Click to collapse
While I agree with what you posted in general terms, below is the link to the thread I was talking about. He did some testing and found the pins aren't just shorted, but shorted w/ 82K resistors to get the maximum charging current.
http://forum.xda-developers.com/showthread.php?t=2274321
Will it damage the phone to have a 3A charger plugged into it? Also If it does not damage would it be able to run the camera as a "blackbox" and not die? I currently have a 2a charger and when i use the black box software it dies after about an hour or so.
SUCCESS!
I got the little black box in from eBay.
Gave it a quick/test wire setup. This is NOT indicative of the end result which will be soldered & have shrink tubing, etc.
Okay, first I grabbed my stock S3 data/charge cable.
Snipped off the standard USB end.
Cut off the ends of the pin 2 & 3 wires since they were not being used anymore (data pins).
Then attached the red (power) from the S3 cable to the yellow (power) lead from the little black box. And did the same for the black (negative) leads.
Then hard wired the red & black from the little black box to my motorcycle battery terminals.
On the first test, I only got 460mAh.
Then I decided to short the 2 & 3 pin wires (green & white) on the S3 cable together (attach them to each other). This gave me 1120mAh!
Next I took the tin-foil and wire braid from the S3 cable and tied them together with the negative lead on the S3 cable. This gave me 1220mAh!
Still not satisfied, I then cut down the 5' S3 cable and made it a 1.5' cable.
AND THIS RESULTED IN A FULL 1920mAh!!!! Right on.
That is exactly the same mAh as the stock S4 wall charger & cable combo give me. Very stoked about this. So now I'll do a nice clean install on the bike and then duplicate it for my car dock sometime soon. FULL CHARGE AHEAD!
Crxdc said:
Will it damage the phone to have a 3A charger plugged into it?
Click to expand...
Click to collapse
No, it will be fine. The phone only draws 1900mAh. If the phone were drawing 3000mAh then there might be a problem.
All done and installed now. And working great!
Negative battery connection (I forgot to shrink tube it but will do that later).
Braided negative wire (~16 to 18awg?) running under gas tank to front of bike.
I wish I would have waited till I got black zip ties in. I hate white zip ties.
The braided wire at the right side of pic that goes up above the gas tank is the pos/neg wire lead that plus right into the phone.
2A inline fuse connecting via blade connector (sorry MC) to a previously used power-on-ignition wire.
This goes to (+) on the little black box.
Note the shrink tube over the braid over the crimp connector (wire goes to top-right of screen).
Phone sitting next to the phone dock I made out of a holster that came with my phone case.
You can see the braided/shrink tubed MicroUSB connector already plugged into the phone.
It's not showing a charge though, because the ignition key is not turned on.
Phone is inserted into stable dock (it will never fall out unless I crash hard).
Ignition is turned on and battery is charging!
And proof that it's charging at the full 1900mAh. Success!
CZ Eddie said:
All done and installed now. And working great!
Negative battery connection (I forgot to shrink tube it but will do that later).
Braided negative wire (~16 to 18awg?) running under gas tank to front of bike.
I wish I would have waited till I got black zip ties in. I hate white zip ties.
The braided wire at the right side of pic that goes up above the gas tank is the pos/neg wire lead that plus right into the phone.
2A inline fuse connecting via blade connector (sorry MC) to a previously used power-on-ignition wire.
This goes to (+) on the little black box.
Note the shrink tube over the braid over the crimp connector (wire goes to top-right of screen).
Phone sitting next to the phone dock I made out of a holster that came with my phone case.
You can see the braided/shrink tubed MicroUSB connector already plugged into the phone.
It's not showing a charge though, because the ignition key is not turned on.
Phone is inserted into stable dock (it will never fall out unless I crash hard).
Ignition is turned on and battery is charging!
And proof that it's charging at the full 1900mAh. Success!
Click to expand...
Click to collapse
Awesome.
Hard wire phone charger and Bluetooth Receiver to car battery plan...
Hello,
I'm planning to install the following in my car along with new stereo head unit:
1) CraigsDocks Samsung Galaxy S4 docking charger, with USB power out
2) Rocketfish Bluetooth Music Receiver (with aptX), with DC 5V power out (connected to 3' 5V to USB power cable)
Plan to use this to convert (found on EBAY - I can't post links here in XDA yet/new user): Dual USB Cable Connectors Power Adapters 8-22V 12 V to 5V/3A DC Volt Converters... to connect directly to my car battery to power both the Samsung charger and the Rocketfish.
I'm new at this and I'm wondering if you all think this will work, or if I'm missing any steps, or if there are other better suggestions?
Thanks for your help!
ebrowni said:
Hello,
I'm planning to install the following in my car along with new stereo head unit:
1) CraigsDocks Samsung Galaxy S4 docking charger, with USB power out
2) Rocketfish Bluetooth Music Receiver (with aptX), with DC 5V power out (connected to 3' 5V to USB power cable)
Plan to use this to convert (found on EBAY - I can't post links here in XDA yet/new user): Dual USB Cable Connectors Power Adapters 8-22V 12 V to 5V/3A DC Volt Converters... to connect directly to my car battery to power both the Samsung charger and the Rocketfish.
I'm new at this and I'm wondering if you all think this will work, or if I'm missing any steps, or if there are other better suggestions?
Thanks for your help!
Click to expand...
Click to collapse
Looks good to me. :good:
http://www.ebay.com/itm/Dual-USB-Ca...064?pt=LH_DefaultDomain_0&hash=item51af639938
ebrowni said:
Hello,
I'm planning to install the following in my car along with new stereo head unit:
1) CraigsDocks Samsung Galaxy S4 docking charger, with USB power out
2) Rocketfish Bluetooth Music Receiver (with aptX), with DC 5V power out (connected to 3' 5V to USB power cable)
Plan to use this to convert (found on EBAY - I can't post links here in XDA yet/new user): Dual USB Cable Connectors Power Adapters 8-22V 12 V to 5V/3A DC Volt Converters... to connect directly to my car battery to power both the Samsung charger and the Rocketfish.
I'm new at this and I'm wondering if you all think this will work, or if I'm missing any steps, or if there are other better suggestions?
Thanks for your help!
Click to expand...
Click to collapse
Just realize that if you wire it to your batter there will be a small draw from the converter and chargers even when not in use. If you let your car sit for a week or long weekend you might come out to find the battery dead. I personally wouldn't wire anything directly to the battery, especially since you didn't mention an inline fuse. Find a switched 12v lead inside the car. Not only does this protect your phone, charger, and car, but it also means you don't have to run anything through the firewall, which is a pain.
You can either tie into the cig lighter wiring, or find something else (I used my clock circuit since it runs to a 10A fuse and is switched).
Caferacer said:
Just realize that if you wire it to your batter there will be a small draw from the converter and chargers even when not in use. If you let your car sit for a week or long weekend you might come out to find the battery dead. I personally wouldn't wire anything directly to the battery, especially since you didn't mention an inline fuse. Find a switched 12v lead inside the car. Not only does this protect your phone, charger, and car, but it also means you don't have to run anything through the firewall, which is a pain.
You can either tie into the cig lighter wiring, or find something else (I used my clock circuit since it runs to a 10A fuse and is switched).
Click to expand...
Click to collapse
Your clock circuit is switched?
I agree with the firewall being a pita, but I'm not a huge fan of tapping on to other circuits either. With nothing charging, what would be drawing any current? If there's anything, it would have to be minimal. It also allows you to charge a phone/device with the car not running, sometimes very handy (and a modification I've made before for just that reason). An inline fuse is also a must, good point!
Sent from my de-Verizonized Galaxy S4, CleanRom style! (using Tapatalk beta 4)
MonkeyTime said:
Your clock circuit is switched?
I agree with the firewall being a pita, but I'm not a huge fan of tapping on to other circuits either. With nothing charging, what would be drawing any current? If there's anything, it would have to be minimal. It also allows you to charge a phone/device with the car not running, sometimes very handy (and a modification I've made before for just that reason). An inline fuse is also a must, good point!
Sent from my de-Verizonized Galaxy S4, CleanRom style! (using Tapatalk beta 4)
Click to expand...
Click to collapse
Yes, my clock circuit has a switched lead to wake up the clock as well as a hard wired lead to retain the time. Both run to the same 10A fuse.
There is a small transformer in the converter and the receiver bluetooth will stay on. They have a small energy draw which is not negligible over a long period of time. At the very least I would include a dash mounted switch to completely shut the charger and receiver off. For instance I have a bluetooth OBD adapter (Not too much unlike your bluetooth receiver) that drained a 2 year old car battery over a week I left the car sitting while I was on vacation. For day to day driving it's not a problem but my OBD adapter isn't hardwired and I can just remove it when I know the car will be sitting.
Thanks
Caferacer said:
Just realize that if you wire it to your batter there will be a small draw from the converter and chargers even when not in use. If you let your car sit for a week or long weekend you might come out to find the battery dead.
Click to expand...
Click to collapse
Oooh, good point! Makes sense to me. I have never done a mod to my car's audio system so I'll be paying a professional installer. I'm so glad to have this information before I shop around at the good places here and get some offers!
Thank you!
Does anyone know if there is any way to use the Surface RT with an external battery pack?
I know there are surface RT compatible powerbanks on sale right now but those are really expensive!
Afaik, the surface charges with 12V whereas USB ports output at 5V.
The only difference that I can tell is that the power output is different. This should just result increased charging times but should not have any safety issues at all.
If you aren't aware what a difference between 12v and 5v means in electronics, you probably shouldn't be giving advice like "should not have any safety issues at all". I mean, you're probably right in this case (though only "probably") but if you think that voltage = power output, it's only by sheer luck.
To answer your actual question, I am not. However, I strongly advise against simply... experimenting with this sort of thing on your own. You could easily start an electrical fire, damage your tablet, or do one of many other unpleasant things.
The surface uses a 7.4V battery pack. Attempting to connect a 5v supply to charge without a stepup converter will not charge the surface at all and instead lead to damaging your 5v supply as the surface attempts to supply 7.4v to it, which may also damage the surface too.
In electronics nothing is more important than the correct voltage. Take a raspberry pi, many people (including myself) use them for electronics projects. Both me and a friend added ultrasonic rangefinders to our pi's except I observed the fact that the module in question uses 5v signalling and my friend did not. We both connected the +5v and ground lines to the corresponding points on our pi's. I connected 1 GPIO pin of the pi to the trigger pin of the HC-SR04 (module in question) as did friend. The pi uses 3.3V on its GPIO pins, the HC-SR04 is safe with a 2.7v-5v trigger voltage, thats fine. The echo pin however is +5v. I ran my echo pin through a voltage divider to give myself a 3.0v output instead, this is safe for the pi (it is fine with 2.7-3.3). My friend did not, he connected the echo pin direct to the pi, tried to use the sensor for the first time ever and found he didnt get any results, do a few test lighting an LED and he found he could no longer use that pin, he damaged it.
I would be more concerned about the surface damaging the supply than the other way around in this case.
However you are correct in believing the device charges at 12V (2A or 4A depending on whether its an RT or pro charger). The surface would have the correct voltage regulation to charge the battery and supply 5v to USB internally. There are 4 wires within the charger. Red: +12V, Black: Ground, Blue: charger detection, Yellow: signal for the charger LED. I don't think its known *exactly* how the yellow and blue wires function, the surface does charge without them. Blue is rumored to be something to do with the RT charger identifying itself as a 2A device and telling the pro to not draw more than 2A (it draws 4) hence damaging the charger but exactly how it does that is unknown. If the 12V supply can supply more than 4A your golden. A supply capable of higher currents than the device needs is actually perfectly safe, current is drawn by the device from the supply, the supply does not force the current at the device. If a device requires 2A and the supply is capable of 10, the supply will still only give out 2 as that is all the device is drawing. A device drawing more than the supply can cope with on the other hand IS DANGEROUS. Lets say you were to use a 5v>12v converter from a computer USB port to charge a surface, a computers USB only supplies half an amp under normal conditions (and by shorting D+ and D- it can do 1.2), the pro trying to draw 4 combined with the inefficiency of 5v-12v stepup converters will cause a current draw so large on the USB port that I would be surprised if damaging the USB port is the only thing to happen, you could fry the entire USB controller easily, damaged USB controllers can then cause their own issues, primarily with this amount of current the possibility of fire.
If you want to charge your surface. Find a voltage source *above* 12V (but not too high above) and use a voltage regulator to make a clean 12V. Then make sure both the regulator and battery can cope with the current. The regulator will determine how far above 12V you are safe to go, some might safely regulate 100V to 12 (most likely a switch mode regulator which although highly efficient won't output a clean 12V, it will have alot of voltage drops and spikes) whereas some might only do 20 to 12 (linear, much less efficient but a very clean 12v, stick a heatsink on it as they get warm). A car battery btw is not 12V, its 12.6 nominal and when fresh off the charger as much as 14.
Yeah, I know the basics of electrical physics. Not a complete speculating noob.
P=IV
Power of a 5V 2.1A is 10.5w
The original power adapter supplies 12V at 2A = 24w
My physics may be rusty but, I was under the impression that it would still charge at lower power output albeit half as fast. I've read that the RT when using the 48W charger would still charge at the same rate as the 24w. This means that the current that is drawn by the surface rt is capped at 2A. Hence, I believe that there would be any significant issues with drawing 2A from a charger that is designed to output 2A anyway though at a lower voltage.
If I'm still wrong here, would love some clarification.
lambstone said:
Yeah, I know the basics of electrical physics. Not a complete speculating noob.
P=IV
Power of a 5V 2.1A is 10.5w
The original power adapter supplies 12V at 2A = 24w
My physics may be rusty but, I was under the impression that it would still charge at lower power output albeit half as fast. I've read that the RT when using the 48W charger would still charge at the same rate as the 24w. This means that the current that is drawn by the surface rt is capped at 2A. Hence, I believe that there would be any significant issues with drawing 2A from a charger that is designed to output 2A anyway though at a lower voltage.
If I'm still wrong here, would love some clarification.
Click to expand...
Click to collapse
The wattage is not of concern. The voltage and current must be treated independently. Also, consider that you are trying to charge a 7.4v battery from a 5v supply, the current will not flow from the 5v to the 7.4v (assume old electrical flow not real electron flow), it will end up doing the opposite, 7.4v flowing towards the 5v.
So lets say you step up the 5v to 12v, there is inefficiency in doing that. To get 12V @2A you would not be drawing 5v @2A, you would more likely be drawing 5V @4 or 5A.
As 6677 says, the Voltage and current (and not the power) are what matters. Power (Wattage) is a derived value (and you correctly gave the derivation); it's handy for making comparisons when certain core assumptions are valid but meaningless on its own. In this case, the core assumptions are *not* valid: not all chargers are producing the same Voltage.
To take another example of where assuming all Watts are created equal would get you in trouble, consider an incandescent light bulb. Light bulbs are rated in Watts because incandescent bulbs operate by turning electrical power (Watts) into heat (also measurable in Watts) via resistive filaments that can only dissipate a limited amount of heat. Thus, a 60W bulb has a filament designed to dissipate 60W of heat. However, since power is a derived value, let's look at what it actually means: In the USA (mains run at about 120V) we can use Ohm's Law: P=I*V; V=I*R, so I=V/R, so P=V*V/R=V^2/R, so R=V^2/P. Therefore, the resistance of a 60W bulb in the USA is (120^2)/60=2*120=240 Ohms. Cool. Now, let's take that 60W bulb from the USA and connect it to European mains. It should still consume 60W of energy and produce the same amount of light, right? After all, it says "60W" right on the box! Hmm... but European mains run at 240V. The resistance doesn't change; it's a physical property of the filament. So, using P=V^2/R, we get P=240*240/240=240W That's four times as much as the bulb is meant to handle; it will flash very brightly (much brighter than normal) and burn out instantly! The bulb isn't defective, it just wasn't made to handle 240V. The "60W" on the box is based on an assumption of 120V; the bulb itself does nothing to ensure that it only consumes 60W.
While the basics of Ohm's Law will equip you to understand things like I describe above, it is *not* enough (by itself) to make assumptions about complex electronics. Even a 101-level electrical engineering course will make that abundantly clear; there are many more forces at play in the world of electronics than the familiar and relatively-easily-understood Voltage, current, resistance, and power.
Thanks guys for clearing the air. Man, I thought it would have been possible to jerry rig a Surface Charging USB cable to be used with battery packs.
So from what I understand, to avoid unnecessary complications, it would be best to find a way to supply 2A @ 12V. Obviously finding a power supply that natively does so is most ideal. But there is an alternative of stepping up the voltage from 5V to 12V with will lead to losses due to conversion inefficiency which basically rules this out.
12V Power Bank
I found a 12V 2.5A external battery pack listed above. This seems to work doesn't it? It has a 12V output with a max draw of 2.5A. The Surface RT draws a maximum of 2A from your power source. I can simply splice the provided cables with the Surface Charging Cable and it sounds to me it'll work.
Since the Surface RT is reported to have a 31.5Wh battery, this battery pack seems to have a 78Wh battery making it rather ideal.
If it is indeed 12V @2A or more then yes, it should charge an RT
Use a power gorilla I use one for my macbook pro and other usb items
Just saw flyer for Surface pro/RT powerbank
Got an email with flyer for Surface + laptop Powerbank. I haven't put an order yet but you can check it out at -> qi-infinity website
It seems they already include Surface adapter and its on sale. I have Lenovo X1 carbon laptop and they have proprietary connector for that one included as well. So I might go with them
Hello all,
! Use this guide at your own risk. I am not responsible for damage to your equipment! You have been warned. Consult a electronics expert if you are not sure!
Click to expand...
Click to collapse
I use my phone a lot, Wifi, game, and the battery is drained fast! I was looking for a solution.
First I used a powerbank 2600 mAh, but that you loose a lot of energy by charging. And it's not practical unless you buy a big powerbank.
A disadvantage is that powerbank will last a limited amount of charge cycles. I ususally use my phone al ot when I am at home.
When I was surfing on the internet I found a person who connected a other brand phone onto a lab power supply and it worked.
So I looked and bought a cheap Basetech BT-153, a set of 4 mm cable set, which includes a pair testing cables with a grapling hook in it.
First you turn the powerdupply on, and set the voltage to the same battery voltage as it's written on yours.
My S6312 has a battery voltage of 3.7V (EB464358VU). So I turn the voltage on the powersupply onto 3.7V. The current (mAh) turning knob does nothing. The current you cannot set at all.
Your phone will draw any current it requires. That's why in most cases you can use a powersupply with the correct voltage , but higher current. Your phone draws a current as it needs. As far as I know off this is in the most cases. Correct me if I am wrong.
Turn the powersupply off before you try to connect the testing probes with their hooks onto your phone. You don't want to short circuit anything.
That can cause malfunction!
I connected the red to plus (+) and the black one to minus (-). You can see which connector is plus or minus on the battery.
The middle one is used to get battery status as I have read. The middle one I did not use. Be carefull to connect plus and minus right!
After connecting the phone will give a warning that the battery is extremely low and that you soulf connect to a powersuppy. Ignore it.
I tried to power my phone by USB only, but that does not work. You have to connect power throught the battery connectors as far as I know.
I saw on youtube somewhere that a guy or girl made a wooden battery shape and placed the contacts onto it. That way you can easily switch between powersupply and battery.
Smart ! :good:
I bought the following items:
http://www.rapidonline.com/test-measurement/voltcraft-ms-6-test-probe-set-51-51631
http://www.conrad.com/ce/en/product/393647/Basetech-BT-153-1-Output-Variable-DC-Power-Supply-Bench
The phone shuts itself down after a while.
I tried connecting the usb cable to give the phone power. But it keeps saying that the battery is removed.
and shuts itself off. Is there a way to override the missing battery in the software? Is there a app that uses root permissions to override that?
If there is , then anyone could use an external powersource without battery.
Anyone?
Installing DisableCriticalBatteryshutdiwn module of the Exposed framework..
REsults: It still shuts down. Emailed Xposed for assistance , hope they have a solution.
Closer to the solution!
http://forum.xda-developers.com/showthread.php?t=2113843
Solder a resistor between the battery minus and the middle pin of the battery.
I used a 1K ohm resistor, that translates to a 4-5% battery charge....
Then I tried a 10K ohm. The battery charge starts at 6% and goes up! How odd?!
But everything works.... Maybe I made an mistake with the resistor value.
http://www.minco.com/Sensors-and-Instruments/Support-and-Tools/Thermistor-Resistance-Table
As the following webpage tells, a copper thermistor, I guess Samsung uses copper resistors, the value is between 5.128 ~ 19.116 ohm.
That could be an explanation that my 1K and 10K ohm resistors are causing my dummy battery is not working properly.
Then I got a warning message to connect my charger. Then I connected my usb connector and no warnings anylonger!
Going to find a better value for the resitor.
I don't have a 220 ohm resistor in my stock. But I do have several 330 ohm. If you connect 2 resistors of 330 ohm in parallel, the replacement resistor (Rv) will be lower than 330.
If you calculate it, it will result in a replacement value of 165 ohm. Link to an online calculator: http://www.sengpielaudio.com/calculator-paralresist.htm
The phone still gives the indication that the battery is only 1% charged and starts charging. The phone shuts itself down after about a minute.
So now the issue is: How to fool the phone that "battery " is full?
I don't own the S6312 any longer. Gave it to a friend who needed. I guess it would work. But alas I cannot verify.
I just started a 2nd try to power my samsung phone without a battery.
But this 2nd try I am going to use a defect battery. Disamantle it and use the electronics of the battery to mimic the original.
Goto: http://forum.xda-developers.com/gen...-battery-2-t2941436/post56779273#post56779273
Edit: The critical power module of the Xposed framework was installed, but not enabled! Shame I cannot test.... Even if you enable it, don't forget to reboot to make it functional!
I'm using an old Samsung GIO (S5660) without a battery, powered through the USB connector.
It requires:
1) disassembling the phone and soldering a wire between the USB power connector to the battery + connector. There's a nice detailed video on youtube that walks through the phone teardown.
2) "special" boot procedure
The soldering part will probably dissuade most people from attempting this as you will need a decent soldering iron + a bit of electronics/soldering experience and a steady hand to solder the wire to the USB connector.
Here's a picture of the wire soldered to the +5V USB pin:
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The wire gets routed through the board where it gets soldered to the +5V battery terminal (unfortunately I don't have a pic of the solder connection to the battery terminal):
Prior to doing this mod, I just connected a 5V source to the battery terminals and the phone powered up fine.
I figured it'd be way cleaner to just tap the 5V power from the USB connector rather than add some other wiring/connector, so I went ahead with this soldering mod.
However, after making the soldering connection the phone wouldn't boot! It would show a battery icon briefly and then shut off.
So I figured there must be some circuitry on the phone that detects that the USB power is connected to the battery terminals but there's no battery there.
Anyways, I stumbled upon the trick "special" boot procedure -- basically boot to recovery (on the GIO, hold HOME key while powering up). From the recovery menu select reboot, and the phone boots up!
I'm using this phone as a tabletop clock and baby monitor receiver:
A nice way to make use of a device that would otherwise be tossed.
Not sure whether this would work for other Samsung phone models...
chihwahli said:
I don't own the S6312 any longer. Gave it to a friend who needed. I guess it would work. But alas I cannot verify.
I just started a 2nd try to power my samsung phone without a battery.
But this 2nd try I am going to use a defect battery. Disamantle it and use the electronics of the battery to mimic the original.
Goto: http://forum.xda-developers.com/gen...-battery-2-t2941436/post56779273#post56779273
Edit: The critical power module of the Xposed framework was installed, but not enabled! Shame I cannot test.... Even if you enable it, don't forget to reboot to make it functional!
Click to expand...
Click to collapse
USB takes 5V and the battery terminal gives 3.3V. Joining these two is going to damage the power IC..
The whole concept does not make sense. Why not plug in the battery and keep the USB charger cable attached, so the battery keeps 100% charge?
Mobile repair technicians use external voltage booster device to power on mobile phones without battery, but its only for a short time.
It would be nice to able to power the phone without the battery when you play a game for 1-2 hours, my phone a Samsung note 3's battery is about 45% charge. That means recharging every day. Since Li-ion batteries last about 500 charge cycles. It does not take long before you need to buy a new one.
Is it a lot of money? No, but its senseless to play on battery if you can play by using an AC adapter.
That's much more efficient., cost effective, and less trash, thus better for the environment.
How many normal / rechargeable batteries get thrown away to be recycled every year? A lot!
Recycling is good, but itś better if you could prevent it. Recycling itself uses a lot of energy and water as well.
You would be surprised what amounts of energy and water that are required to separate trash and re-use it.
It's better to prevent creating more and more trash....
Samsung?? Apple?? Anyone?? A phone-dock or cable that can run a smartphone without battery please!!!!
Well, that is one product I would really like to have! Sell it to me! I have my cash ready =) Hit me!
Hmmm, going to try that later.... thanks.
AlbertDude said:
I'm using an old Samsung GIO (S5660) without a battery, powered through the USB connector.
It requires:
1) disassembling the phone and soldering a wire between the USB power connector to the battery + connector. There's a nice detailed video on youtube that walks through the phone teardown.
2) "special" boot procedure
The soldering part will probably dissuade most people from attempting this as you will need a decent soldering iron + a bit of electronics/soldering experience and a steady hand to solder the wire to the USB connector.
Here's a picture of the wire soldered to the +5V USB pin:
The wire gets routed through the board where it gets soldered to the +5V battery terminal (unfortunately I don't have a pic of the solder connection to the battery terminal):
Prior to doing this mod, I just connected a 5V source to the battery terminals and the phone powered up fine.
I figured it'd be way cleaner to just tap the 5V power from the USB connector rather than add some other wiring/connector, so I went ahead with this soldering mod.
However, after making the soldering connection the phone wouldn't boot! It would show a battery icon briefly and then shut off.
So I figured there must be some circuitry on the phone that detects that the USB power is connected to the battery terminals but there's no battery there.
Anyways, I stumbled upon the trick "special" boot procedure -- basically boot to recovery (on the GIO, hold HOME key while powering up). From the recovery menu select reboot, and the phone boots up!
I'm using this phone as a tabletop clock and baby monitor receiver:
A nice way to make use of a device that would otherwise be tossed.
Not sure whether this would work for other Samsung phone models...
Click to expand...
Click to collapse
By keeping the smartphone, with battery attached to the charger. The battery life is going to shortened. Some people say that keeping the battery charge between 40% and 80% is optimal. Charging to 100% shortens battery life. Battery guides from various websites tell that. But if this is true for every kind of li-ion battery I wonder.
Attaching USB 5.0v to the battery contact directly is risky, damage is possible.
I am not sure how much extra voltage is circuit can take without going over it's limit. It might cause the electronics to work less long due to higher voltage. As in the formula: U= I x R
U = voltage
I = current
R = resistance
With higher voltage, the current will increase: I = U / R.
For instance:
i = 5 / 100 = 0.05 A = 50mA
i = 3,3 / 100 = 0,033 = 33 mA
The higher current will cause diverse electrical components to have a higher voltage, some components are made for a specific voltage. Using a higher voltage could result in damage. It's better not to take a chance...
sudeshkmr said:
USB takes 5V and the battery terminal gives 3.3V. Joining these two is going to damage the power IC..
The whole concept does not make sense. Why not plug in the battery and keep the USB charger cable attached, so the battery keeps 100% charge?
Mobile repair technicians use external voltage booster device to power on mobile phones without battery, but its only for a short time.
Click to expand...
Click to collapse
First you have to look for the voltage output your battery is giving. All batteries give different voltage output but its around 3.3V mostly. Then use a simple voltage regulator to drop-down the voltage. For example if your battery is giving 3.3 V output. then you can use LM7833 circuit for converting 5V to 3.3V.
IIRC, a fully charged lithium-ion battery has an output voltage of 4.2 V, fully discharged around 3.5? V
So the device most likely regulates the voltage from the battery anyways.
If you have no need for the device to be portable (as I said, I'm using it as a desktop clock and baby monitor) and you no longer have a battery (mine started bulging so it was time to throw it away...) then it's nice to be able use the device without having to buy a new battery.
Been running over a month with no overheating or other related problems.
sudeshkmr said:
USB takes 5V and the battery terminal gives 3.3V. Joining these two is going to damage the power IC..
The whole concept does not make sense. Why not plug in the battery and keep the USB charger cable attached, so the battery keeps 100% charge?
Mobile repair technicians use external voltage booster device to power on mobile phones without battery, but its only for a short time.
Click to expand...
Click to collapse
That is a nice idea to lower the voltage from 5V to any voltage required.
But the problem I face is, is how to fool any 3 pin Samsung battery that there is a battery attached??
I have not tried the trick by connecting the micro USB 5V, then through a voltage lowering circuit like yours, and attach it to the battery pins of my phone. Then attack micro USB, and see if it works.
I wonder if that is safe to try.
I'd expect the device to regulate the voltage from the battery terminals so it's overkill to add another regulator.
If you're worried about the voltage being too high, just insert one or two (depending on your level of worry) forward biased diodes to drop the voltage by ~0.7 V or ~1.4 V.
I'm comfortable with leaving it at 5V....
sudeshkmr said:
First you have to look for the voltage output your battery is giving. All batteries give different voltage output but its around 3.3V mostly. Then use a simple voltage regulator to drop-down the voltage. For example if your battery is giving 3.3 V output. then you can use LM7833 circuit for converting 5V to 3.3V.
Click to expand...
Click to collapse
Ok, voltage sounds ok. As you have said, if I want to lower it I could.
@AlbertDude: How many pins does your samsung phone battery have? 3 pin batteries are easy to attach to a power-supply , Samsung's 4 pin li-ion batteries are different.... Samsung ace 3 has 3 pin battery.
Ace 3 works with power-supply and a resistor between ground and the middle pin.
Samsung Note 3 has a 4 pin battery and this a bit different. Tried several resistors, but the phone keeps detecting that it has no battery. So it will not boot past the Samsung screen. It just shuts down...
But I still have to try the boot into recover and reboot from that screen. Maybe it does work, not sure yet.
If someone tried or has a new idea. post =)
AlbertDude said:
I'd expect the device to regulate the voltage from the battery terminals so it's overkill to add another regulator.
If you're worried about the voltage being too high, just insert one or two (depending on your level of worry) forward biased diodes to drop the voltage by ~0.7 V or ~1.4 V.
I'm comfortable with leaving it at 5V....
Click to expand...
Click to collapse
The Samsung GIO has 3 pin battery.
For the GIO:
- The "boot from recovery" trick was only needed after soldering the wire between the USB and battery pins. When I connected an external 5V source to the battery pins, the device powered up without problems.
- I have never had to use any resistors.
Good luck!
chihwahli said:
Ok, voltage sounds ok. As you have said, if I want to lower it I could.
@AlbertDude: How many pins does your samsung phone battery have? 3 pin batteries are easy to attach to a power-supply , Samsung's 4 pin li-ion batteries are different.... Samsung ace 3 has 3 pin battery.
Ace 3 works with power-supply and a resistor between ground and the middle pin.
Samsung Note 3 has a 4 pin battery and this a bit different. Tried several resistors, but the phone keeps detecting that it has no battery. So it will not boot past the Samsung screen. It just shuts down...
But I still have to try the boot into recover and reboot from that screen. Maybe it does work, not sure yet.
If someone tried or has a new idea. post =)
Click to expand...
Click to collapse
AlbertDude said:
I'd expect the device to regulate the voltage from the battery terminals so it's overkill to add another regulator.
If you're worried about the voltage being too high, just insert one or two (depending on your level of worry) forward biased diodes to drop the voltage by ~0.7 V or ~1.4 V.
I'm comfortable with leaving it at 5V....
Click to expand...
Click to collapse
Good and valid points.
For the middle point of battery which (in most batteries I assume) senses the temperature of battery through a thermistor, you can do things. Either use a thermistor yourself (again overkill) or just use a resistor. The value of resistor can be chosen so that it gives half of battery's voltage output which is around 1.6 V. This can be done using a voltage divider circuit easily.
here!
I came down to this post when i want to have my pocket wifi "battery"-less.
See if this helps
m.instructables.com/id/How-to-use-phone-without-battery
This is my first post so try to copy the set of words above on google and look at it on
the instructable website
Cheers!
Maybe it's time to get out and do something productive. Like possibly, putting your phone down and make a power supply for what you're looking for? Reading all these comments, you all seem reasonably intelligent and I would be willing to bet that if you focused your time on the problem instead of a game, whomever would most certainly figure out a solution. Yeah?
To find a way to replace a 4 pin battery with any powersupply. Someone with electronics skill could for example measure the signals from all the 4 pins of the battery with an oscilloscope. I guess. Based on the signals create a electronics schematic that will mimic those signals. I guess that will work.
But I do not have the skills nor the oscilloscope to try it out.
I'd like to know if there is a way to build an electric circuit to allow you to power up and operate a Nexus 5 without a battery attached.
I'd like to use the Nexus 5 as a "fixed" device, always on, always connected to the mains. Leaving the battery inside will cause it to age and eventually burst.
I'm guessing I could either try to feed the phone 3.8V (as the battery is rated), but I can't send the battery temperature values on its connector, or destroy the battery, remove the battery elements and leave the electronics in place and feed it current from there.
Before I break something, I'd like to ask if it has been done already.
Thanks!
-
inigo333 said:
Any success doing so? (inigo333 at gmail.com)
Click to expand...
Click to collapse
I haven't had time to try it yet, but a colleague suggested I try adding 2 diodes on the 5V line from USB to lower the voltage to 3.8V. I will plug this into the battery's circuit, replacing the other elements. I'll let you know when I get around to doing it (in a month or so).
Did it work?
Though it's been years - I haven't had time to try it
When I do, I'll probably go with one diode and supply 4.3V to the battery pins - because Li-Ion batteries can go to 4.3V...
Best solution for battery problem.
Attach 2 numbers of 18650 lithium cell of capacity 2200mah in parallel using smd type battery holder at the back panel.
Add an external li-ion battery charging module chip on the same side.
Take the internal battery's power management chip, discard the internal cell.
Connect externally attached battery power (+) & (-) ve to the internal power management chip of old battery.
Re assemble the mounted unit. Charge externally and enjoy.
Only problem is that, slim set becomes bulky.
Thanks,
But the problem is I wanted to run the Nexus 5 without a battery (from a charger). The goal being - it is always on, and there are no batteries to swell..
mad_ady said:
Thanks,
But the problem is I wanted to run the Nexus 5 without a battery (from a charger). The goal being - it is always on, and there are no batteries to swell..
Click to expand...
Click to collapse
The MT3608 2A Max DC-DC Step Up Power Module Booster Power Module is a low-cost module that can step-up a 2 to 24V input voltage up to a 5 to 28V output at up to 2A.
Use it inside the battery compartment.
Before installing preset output to 3.7-3.8 volt.
Fix it and use on dc 5 volt charger.