Related
Hi, I'm really a noob when it comes to electronics. For all I know, when a cable fits it should work
I have a couple of microUSB chargers laying around. They all have an output of 5 Volt but they output a currency that differs from the standard charger (1A).
What is the "golden rule" wrt currency? Are chargers with a currency that is less than 1A save?
current is not pushed, it is pulled by your device as necessary. voltage is pushed, so correct voltage,5V in this case, is very important. As for the current, if the charger can't supply enough current with that voltage it will get hot and cause problems. i.e., you should have a current greater or equal to your original charger and same voltage. this applies to ALL of your electronics.
ozkaya said:
current is not pushed, it is pulled by your device as necessary. voltage is pushed, so correct voltage,5V in this case, is very important. As for the current, if the charger can't supply enough current with that voltage it will get hot and cause problems. i.e., you should have a current greater or equal to your original charger and same voltage. this applies to ALL of your electronics.
Click to expand...
Click to collapse
Thank you very much for this explanation. What do you think, a 5v charger with a current of 850mA will that cause big problems when I use it just accidentally to charge my device.
appelflap said:
Thank you very much for this explanation. What do you think, a 5v charger with a current of 850mA will that cause big problems when I use it just accidentally to charge my device.
Click to expand...
Click to collapse
It probably wouldn't be a lot of problems, if you really have to do it, charge it when the screen is turned off, so that you will need less current.
You can charge without risk with any USB charger. Unless the charger "signals" that it can supply more than 500mA by having the 2 USB data pins shorted, the HD2 won't pull more than 500mA, which is the minimum a USB charger must be able to supply.
"Golden rule" - If You have 5V its safe for Your phone, current level is determining the time that You need to charge battery.
Kilrah sad that HD2 'pull' no more than 500 mA - ok, if this is true ( i believe it is , he always make some test for it ) original charger needs about 2h, with 250 mA charger it will take more than twice of that time - 4h ( it's not fully linear )
@Kilrah - did You test what's power ( current taken ) consumption during charging ? it's really only 500 mA ? if so, than why HTC use 1A charger ? usually safety rules are about 15 - 30% more than max current needed.
0.5 A + 30% = 0.65A , so why 1A ?
The minimum current what HD2 accepts is 500mA because this is the USB standart.
If the supply could deliver more than 500mA the HD2 will take it up to 1000mA. The maximum current which the HD2 can use is 1A (1000mA).
So if your charger can deliver 5V and 2000mA the HD2 will limit the current to 1000mA. So you can use a charger, when the voltage is 5V and the current at least 500mA.
The push pull principe in the post before is correct, because the charger is a voltage source and not a current source.
I am already enjoying the benefits of proposed standardisation of phone chargers to micro usb pin. Since I upgraded with HD2 from Nokia N97 I am using the nokia wall chargers as well as well as car charger. I didnt have to buy new charging accessories for this mighty HD2.
By the way would the Nokia data cables (micro usb) be able to sync data when used with HD2. Havent tried yet.....
afropolak said:
@Kilrah - did You test what's power ( current taken ) consumption during charging ? it's really only 500 mA ? if so, than why HTC use 1A charger ?
Click to expand...
Click to collapse
As said, IF the 2 USB data pins are NOT shorted (that's how it is by default on <500mA/3rd party chargers, or on a PC), the HD2 will limit the current it pulls to ~450mA.
IF they are shorted (on chargers that support higher current like the supplied one) the HD2 will pull more. With the supplied charger it's about 850mA, with a 3rd party "800mA" Chinese charger that didn't have the pins shorted but was modded to have it done, it pulls about 650mA.
PlayStation said:
By the way would the Nokia data cables (micro usb) be able to sync data when used with HD2. Havent tried yet.....
Click to expand...
Click to collapse
Micro USB is a standard, so every micro USB cable should be the same. If not, you've got a botched knockoff.
so how do you short the cable assuming I get a car charger without a USB to micro USB cable and sourced my own cable from a parts bin that was probably for computer usage?
cheahcl said:
so how do you short the cable assuming I get a car charger without a USB to micro USB cable and sourced my own cable from a parts bin that was probably for computer usage?
Click to expand...
Click to collapse
I don't think that would be a good move!
You would have to be certain of the regulation circuitry of the charger and it's ability to cope with the attendant initial draw of the battery when plugged in.
This will depend on the state of drain of the battery and the various functions in operation at the time on the phone.
At the moment of plugging in is when the draw will be highest and when any protection circuitry will be essential.
A well topped up battery will "draw" less than a depleted one and will continue charging on as little as 350mAh (again depending on what is running on the phone).
A very depleted battery may well not even start the charging process at such a level. That's why the HD2 comes with a 1000mAh wall charger!
The levels quoted for PC/Laptop USB power are nominal off load levels and will vary depending on any othe devices plugged in on the same bus supply.
So, with a PC that has a few attached USB devices, you may well NOT see 500mAh and as has been reported before, you can get battery depletion back into the USB port as other devices draw from the phone!
Always best to keep the battery topped up to prevent "charging strain" on the cells. This will maximise the capacity available when you need it for those longer periods of time.
Hi there!
My brother just bought me a spare battery. Well it still needs to be charged after usuage. The thing is I have to swap the batteries everytime I used them both. The solution is to buy a cradle to charge it but these are kinda expensive.
My solution would be to build my own charging cradle. But I lack the knowledge of electricity skills to succesfully making such charger without blowing up my battery. Therefor I'm asking the community on XDA for help!
Well this is what I need:
- Battery has 3 connectors: + and - and on in the middle but i dont know what that is.
- I have a usb cable with 4 wires (black/red/green/white)
- I want to connect the usb connecter to my PC or AC adapter and the wires to my battery.
This way I can charge both my HD2 and the spare battery at the same time.
The question is, is this possible and if yes, can this be done just like that or do I need transistors or conductors (or whatever they may called). It needs to be safe, I dont wanna blow up my battery or my AC adapter nor my PC...
Do not even contemplate it.
It is clear that you do not know enough about batteries.
A quick google for desktop chargers came back with one for only £30
For 25quid i got a spare battery, desktop charger and 2 screen protectors from e-bay. Carnt go wrong at that price
I know that the AC adapter converts the input of electrical energy to my phone, I believe my phone does it to my battery too (thats where I'm not too sure).
All I need to know is if I can charge the battery safely when connecting the red wire to the + and the black wire to the - side of the battery... (The green and white wires are data)
I'm not to sure because the AC adapter has a different output than the PC USB output. Although the USB dilivers a tiny bit less voltage it delivers a significant less amount of Whats (or Amps) Basicly that means it just takes longer for the USB to charge as long as the voltage remains identical. (The USB delivers less voltage but the effect on damaging the battery is minimal because the difference is discardable)
My actuall question was: can I connect my battery directly to the AC adapter or do I need to convert the electical energy again (if my phone does a second convert after the AC adapter).
You can find chargers on eBay for less than 5usd. Buy one or you will fry your battery.
VerusAmos said:
I know that the AC adapter converts the input of electrical energy to my phone, I believe my phone does it to my battery too (thats where I'm not too sure).
All I need to know is if I can charge the battery safely when connecting the red wire to the + and the black wire to the - side of the battery... (The green and white wires are data)
I'm not to sure because the AC adapter has a different output than the PC USB output. Although the USB dilivers a tiny bit less voltage it delivers a significant less amount of Whats (or Amps) Basicly that means it just takes longer for the USB to charge as long as the voltage remains identical. (The USB delivers less voltage but the effect on damaging the battery is minimal because the difference is discardable)
My actuall question was: can I connect my battery directly to the AC adapter or do I need to convert the electical energy again (if my phone does a second convert after the AC adapter).
Click to expand...
Click to collapse
Watts not Whats
Simple answer: No you cannot connect your battery directly to the AC adaptor.
Detailed answer:
The USB port of a computer/AC adaptor provides approx 5V and a variety of currents depending on what the USB lead is plugged into.
This 5V goes to the phone.
Inside the phone is the battery charging circuit, this detects the level of charge in the battery, controls the voltage and current going to the battery to stop it releasing too much hydrogen which would cause the battery to swell and explode (look on youtube for lithium polymer battery fires).
If you think you can create a charging circuit (including selecting the right ICs and programming them) without burning yourself in a hydrogen/lithium fire, be my guest.
Incapable of making an external battery charger...
Here I am trying not to be a complete idiot and then I go and spell watts the wrong way...
But tnx for the replies, that was all I needed to hear... I guess I'll be swapping batteries after all untill I find a cheap external battery charger...
Cheers!!!
Amzer makes a very nice cradle with charging slot for your spare battery. I got mine for $28USD. I'm not going to provide the link to the outfit I bought mine from because they weren't the best of suppliers to buy from. But the Amzer cradle works very well. Downside is that you cannot use it if you have a case for your Leo that wraps around it, and is designed to stay on. Leo must be caseless to fit into the cradle. But even if you don't use the cradle as a cradle, it does have the ability to charge your spare battery.
Does the nook on-board regulator have current limiting? Or are the wall warts and car power adapters limiting the maximum current.
I know the standard usb ports limit to 500ma in most cases, but with the appropriate cable and connections, the nook will request the higher USB ratings, 1.9 amps on my stock wall wart and stock power cord.
Are car chargers built with usb sockets limited to some usb spec of 2 amps or so?
A simple 5 volt regulator in a car socket could theoretically supply 10-30 amps depending on its fusing.
What I am wondering is say, a gell cell or NiCd pack with high current ability could be connected to the nook, using the high power usb pins enabled to on would be safe, or would the Nook be expecting a limited power source.
I'm afraid if i connect a 5v 10A plus source like above, and there is no self current limiting, I might blow an internal fuse or input resistor.
I want to take the thing on a trip, and was hoping a battery pack in my bag with a female USB jack (the center two pins shorted, and the stock cable) would be able to charge the unit when away from both the AC and car power.
Thanks.
P.S. On a related note, do airlines now have 120 volt outlets at all seats so I could use my nook charger?
nerdful1 said:
Does the nook on-board regulator have current limiting? Or are the wall warts and car power adapters limiting the maximum current.
I know the standard usb ports limit to 500ma in most cases, but with the appropriate cable and connections, the nook will request the higher USB ratings, 1.9 amps on my stock wall wart and stock power cord.
Are car chargers built with usb sockets limited to some usb spec of 2 amps or so?
A simple 5 volt regulator in a car socket could theoretically supply 10-30 amps depending on its fusing.
What I am wondering is say, a gell cell or NiCd pack with high current ability could be connected to the nook, using the high power usb pins enabled to on would be safe, or would the Nook be expecting a limited power source.
I'm afraid if i connect a 5v 10A plus source like above, and there is no self current limiting, I might blow an internal fuse or input resistor.
I want to take the thing on a trip, and was hoping a battery pack in my bag with a female USB jack (the center two pins shorted, and the stock cable) would be able to charge the unit when away from both the AC and car power.
Thanks.
P.S. On a related note, do airlines now have 120 volt outlets at all seats so I could use my nook charger?
Click to expand...
Click to collapse
I'll answer the postscript first: Nope. It's a rare plane that has ANY 120 V outlets in coach. If you're willing to fork out the cash for first class it's probably a fifty-fifty chance.
nerdful1 said:
Does the nook on-board regulator have current limiting? Or are the wall warts and car power adapters limiting the maximum current.
I know the standard usb ports limit to 500ma in most cases, but with the appropriate cable and connections, the nook will request the higher USB ratings, 1.9 amps on my stock wall wart and stock power cord.
Are car chargers built with usb sockets limited to some usb spec of 2 amps or so?
A simple 5 volt regulator in a car socket could theoretically supply 10-30 amps depending on its fusing.
What I am wondering is say, a gell cell or NiCd pack with high current ability could be connected to the nook, using the high power usb pins enabled to on would be safe, or would the Nook be expecting a limited power source.
I'm afraid if i connect a 5v 10A plus source like above, and there is no self current limiting, I might blow an internal fuse or input resistor.
I want to take the thing on a trip, and was hoping a battery pack in my bag with a female USB jack (the center two pins shorted, and the stock cable) would be able to charge the unit when away from both the AC and car power.
Thanks.
P.S. On a related note, do airlines now have 120 volt outlets at all seats so I could use my nook charger?
Click to expand...
Click to collapse
As to the current limiting, yes, most car chargers are pretty low power, usually rated to an amp or so. It's pretty hard to find one that will match the stock wall wart in amps.
I would be careful of a simple linear regulator in a car charger, as you'd be dumping a lot of power directly to heat. Each amp of current would put 5 watts out the usb port and burn 7 watts in the regulator. Won't take long to start a fire that way.
Now, lithium ion batteries normally have pretty sophisticated charge control circuitry, as too rapid of a charge could cause it to burst into flames. If you decide to test your idea make sure you have a good class C fire extinguisher handy!
To update my airplane power question of years ago: Since then, I've been traveling a lot and have found USA 120 volt outlets in all planes. Both in 1st and cramped class.
Also on Amtrak train and busses.
Going to poke around with my retired Nook Color for ham radio and bench schematics, etc.
Background
Hi all, I, for a very short period of time was suffering from the problem of my phone DISCHARGING while it was charging. This made no logical sense to me until I did some research, which I will detail below.
How USB Power works (Roughly)
Firstly let's discuss USB power provisioning. Strictly speaking, the specifications say that any given USB port should provide a maximum of 500mA (or 0.5A) at 5 volts. *Don't shoot me electronics guys, I'm simplifying for ease of explanations sake*. Imagine that ampage as the actual force of the charger, how quickly it can ram power into your phone. Like the rate of flow on a pipe.
The beginning of the problem
This was all fine and dandy when all USB was really used for was Keyboards, Mice, Memory, etc, low current draw devices. Something else I should mention here is that the Ampage that a port CAN provide is not the Ampage it DOES provide - the device draws a certain Ampage and if the USB controller agrees it outputs said Ampage. Later, when USB was beginning to be used for more power hungry applications, ie External hard drives, these required more power than the port could (In theory) provide. However, most more modern motherboards/USB controllers were more than capable of supplying plenty more Ampage if it was requested. This was breaking the specification but not in any massively dangerous way so as such nothing bad happens.
This is where we get to the actual issue people are experiencing here. The Nexus 4 is a standards compliant device in the respect that it seems to only draw 500mA from any USB port no matter what it's potential, unless it's an AC Wall wart. If you're experiencing problems with wakelocks (see XDA) and other things, this causes your phone to draw more than 500mA which means your phone actually discharges while it's charging! Terrible!
This is quite easy to get around, but again I'm going into detail so let's explain how the phone tells the difference between a dumb wall wart and a USB controller. Easily! The USB controller obviously makes use of the data pins found within the USB cable, whereas a wallwart just (almost always) shorts them out. The Nexus 4 can detect this short, and as such draw more power *While still in quotation marks staying in spec*.
The root problem is not with how the N4 is charging, it's with the wakelock you're experiencing which is causing the phone to draw so much power while the screen is off. While the screen is off and the phone is in Deepsleep (A CPU state where it uses very little power) - it should draw no more than 50mA leaving 450mA for charging the battery, but you guys are probably experiencing a wakelock of some sort.
Solutions to the problem or How to break a specification for the good of mankind
The simple solution is to install this app: https://play.google.com/store/apps/details?id=com.rootuninstaller.batrsaver
This forces the device into a Deep sleep when the screen goes off by killing applications and turning off all internal chipsets that have wakelock capability, most commonly networking on the Nexus 4. This will allow your phone to charge (slowly) off USB without an issue. Another common wakelock is when the device is picked up by your desktop as a media device. The USB controller inside the Nexus 4 forces a wakelock which keeps it from charging. Stupid design, I know.
* A more hackish solution is to install Francos kernel, buy his app, and tick the Fast charging option in the kernel settings dialog. This will force the phone to think that everything is an AC adaptor and will force the phone to draw as much current as it can from the USB port (which on most modern motherboards is fine, and results in extremely quick charging).
* An even simpler solution than all this is to just use a 'USB Charging cable' - this is simply a cable that does not have the Data pins, and as such does exactly the same as what enabling USB fast charge above does. http://www.ebay.co.uk/itm/Micro-USB...487076?pt=PDA_Accessories&hash=item51a465d124
If you live near a Poundland store here in the UK they sell a 4 in one USB cable type thing which turns 1 USB port into Ipod sync connector, Nokia connector, MicroUSB and MiniUSB, and this doesn't have the data pins and as such is excellent.
One final point, an excellent app for monitoring whether your device is actually charging or not and how quickly is Current widget: https://play.google.com/store/apps/details?id=com.manor.currentwidget&hl=en
This widget will tell you how much Ampage is going into or leaving your battery. If the battery icon is green, then it's discharging, if it's black/white then it's charging. The bigger the number, the faster the discharge/charge. This is an extremely easy way to test speed of chargers too.
Recommendations
Another solution, just use an AC Wall wart - they're cheap as hell and the one supplied with the Nexus 4 is an extremely fast charging one. Shame I've gone and lost mine.
A way to roughly monitor charging current draw
I'd also recommend you install https://play.google.com/store/apps/details?id=com.manor.currentwidget&hl=en and monitor, if the battery is green while charging it's discharging and you need a more powerful charger/to figure out what's causing your phone to use so much power.
General good values in Current Widget
I generally saw a max draw of about 750mA for charging (not including draw for powering the device, the Nexus 4 can draw more power to charge and power the device) on my old Rev10 first generation Nexus 4. On my new Rev12 board I'm noticing this increase to about 850mA.
Are higher amperage chargers any benefit to anyone?
Yes and no. You will not notice faster charging unless you use your device while charging. Your nexus will draw as much power as it needs to power the phone while charging at the fastest rate. For example on the stock 1.2a charger
1200mA | 800mA goes to charging 400mA goes to powering the phone idling
Let's say you start a stability test. Your phone will obviously be using a lot more power so this will happen
1200mA | -600mA goes to charging and 1800mA goes to powering the phone stability testing
That minus value above may look strange! Let me explain. If the phone needs more power than the charger can supply, it will draw from the battery. That's the minus number.
If you have a higher ampage charger like for example a 2.5a charger
2500mA | 800mA goes to charging 400mA goes to powering the device
Stability testing
2500mA | 700mA goes to charging 1800mA goes to powering the device
Can you see the difference?
DISCLAIMER: I am not an electronics engineer nor do I claim to be, I am simply a hobbyist and this is what I've found to be the case. Please correct me if I've made any mistakes, I want to learn.
Thanks!
Thanks so much for this post. It's very helpful.
kn100 said:
Another common wakelock is when the device is picked up by your desktop as a media device. The USB controller inside the Nexus 4 forces a wakelock which keeps it from charging. Stupid design, I know.
Click to expand...
Click to collapse
This isn't true for everyone then as mine connects and charges just fine off of my laptop and desktop when connected as a media device. In fact its on my laptop right now charging, gone from 68% to 81% in about 30 minutes and it shows connected as a portable media player.
Great info! Thanks for writing this!
In certain use cases the Nexus4 discharges faster than it charges and this is a very useful guide.
I use my phone for navigation in my car and having the GPS on and the screen at high brightness
drains the battery faster than the 0.5A car chargers can supply. Car chargers rated for 2.0A work well.
I haven't tried a 'USB charging cable' with the data pins shorted, it may work as well.
-Mindroid- said:
Great info! Thanks for writing this!
In certain use cases the Nexus4 discharges faster than it charges and this is a very useful guide.
I use my phone for navigation in my car and having the GPS on and the screen at high brightness
drains the battery faster than the 0.5A car chargers can supply. Car chargers rated for 2.0A work well.
I haven't tried a 'USB charging cable' with the data pins shorted, it may work as well.
Click to expand...
Click to collapse
was over in Nexus 7 forums and the 4.2.x kernel should have solved the problem at least for having to use shorted cables. have to wait and see if 4.2.2 brings any more changes.
http://forum.xda-developers.com/showthread.php?t=1984838
Section 6 in this link is about power supplied through USB
http://en.wikipedia.org/wiki/Universal_Serial_Bus
I can't tell if we have an updated kernel allowing faster usb charging as I'm limited by the power output of the usb port in my laptop. The output (5V at 500mA max) is controlled by the laptop (USB Standards) and it doesn't matter what the phone or cable is capable of as that's the max it will give out and that's about what I'm charging at. If I had a dedicated charging port in my laptop then it would be different and I could see if its able to draw more power. I have a 1.0 amp port in my car and it does charge at the higher amperage, I would assume it would do the same thing if I had a 2 amp usb port in the car. So I think the stock kernel has the fast usb charge built in it just depends upon if you have a usb port capable of providing a faster charger, it has nothing to do with the cable as I'm using a standard unmodified micro usb cable and its able to draw the max a usb device is able to put out.
thanks
thanks for a great detailed post!!!
I have the same trouble with my N4 when I was charging while using my phone...
I find it very slow... I guess I've been spoiled by my previous iPhone (which charges fairly fast)....
i might be stating the obvious but I find the phone charged "a lot" faster when it's OFF
if you are running low with your battery and need a quick 10 min charge, just do yourself a favour by turning off your phone...
the difference is quite significant!
kzoodroid said:
This isn't true for everyone then as mine connects and charges just fine off of my laptop and desktop when connected as a media device. In fact its on my laptop right now charging, gone from 68% to 81% in about 30 minutes and it shows connected as a portable media player.
Click to expand...
Click to collapse
Yup, me too. It only discharges while charging when I am playing like NFS most wanted.
Sent from my Nexus 4 using xda app-developers app
The issue with cables is with the LG usb wall charger as the one supplied isn't capable of getting the 5 volts at 1.2 amps that the charger is rated at, mine is getting around 300 - 400 mA. The micro usb cable I have in my car and use with my laptop (for charging and data transfer) is able to handle the higher amperage, it gets around 1 amp with the LG plug. There are no specs on these cables so I can't list a definitive difference and I would assume that the cable mod in the OP might help with the LG cable. It also might just be simpler to only buy those cables capable of handling higher amperage as obviously they are out there from my experience.
The cable I'm using is an RCA coiled charging/syncing cable model AH732CBR (has data pins). The maximum I'm getting from this is about 870 mA regardless of the amperage of the usb port, I've tried a 1.0, 1.2 and 2.1 and they are all around 870 mA on current widget. I would suppose if I could find a strictly charging cable I could get higher (link to ebay in OP is outdated) but this is still 2x that which I'm getting from the LG cable supplied with the phone which only puts out 300-400 mA. Our phone also has Qualcomm's quick charge which is supposed to improve battery charging times by 40%.
http://www.droid-life.com/2013/02/1...allows-your-device-to-charge-up-to-40-faster/
How do you measure how much mA the device draw from the charger?
Sent from my Nexus 4 using Tapatalk 2
omrij said:
How do you measure how much mA the device draw from the charger?
Sent from my Nexus 4 using Tapatalk 2
Click to expand...
Click to collapse
current widget, link is in the OP
kzoodroid said:
The cable I'm using is an RCA coiled charging/syncing cable model AH732CBR (has data pins). The maximum I'm getting from this is about 870 mA regardless of the amperage of the usb port, I've tried a 1.0, 1.2 and 2.1 and they are all around 870 mA on current widget. I would suppose if I could find a strictly charging cable I could get higher (link to ebay in OP is outdated) but this is still 2x that which I'm getting from the LG cable supplied with the phone which only puts out 300-400 mA. Our phone also has Qualcomm's quick charge which is supposed to improve battery charging times by 40%.
http://www.droid-life.com/2013/02/1...allows-your-device-to-charge-up-to-40-faster/
Click to expand...
Click to collapse
Bit of a late reply but please bear in mind the Nexus will NOT draw anything more than about 800mAh from the wall for charging alone. That is the absolute max and is a hardware limit - If the cable is transmitting that and it's showing in current widget you've got a good setup. See the added section in OP for more info on higher amperage chargers.
Team,
First off, I want to say thank you for creating an amazing resource for these phones. I currently have a Galaxy S4 Active MF3. I bought the phone with the intent of using it in conjunction with my car stereo, which is a Pioneer 8500 BHS. I've paired this up with a Samsung MHL 2.0 adapter and ARLiberator. On top of this, I have installed a OBD-II bluetooth module in the car that also communicates with the phone. The end result is that the phone delivers full touch screen control of all apps on the phone, full bluetooth hands free calling, voice control, GPS (Tom Tom), Pandora, and most importantly, gives me a second dashboard where I can customize any gauge that the car did not offer stock, such as boost gauge, wideband air/fuel ratio, exhaust gas temperature, and a few other things. I'm using the full version of Torque to do this. It is amazingly useful, with one exception. The Samsung MHL adapter never lets the phone charge at more than 300 milliamps. The USB connection straight from the stereo charges at 900, and a 2.1 AMP charger with the Samsung cable will charge at 1900. However, regardless of the combination I use, the MHL always cuts this down to 300. This causes the phone to lose about 15-20% of it's charge every hour. For short trips, this is OK, but for longer trips, I can no longer use GPS, which is a big problem, as that's the whole reason I got the phone. Other users of the standard Galaxy S4 and this combination have been able to get around this issue by installing a ROM with Fast Charge enabled, which gives them 800 milliamps. This is just enough to let the phone be used and slowly charged at the same time.
I understand that currently we're limited to stock kernels with modifications layered on top (GoldenEye, ETC...), and that the Fast Charge code requires a kernel recompile in order to function. Is this correct? Do I have any other options? I've considered wiring in a wireless charger just to get the phone to charge on long trips, but I'm concerned that wireless charging in addition to the USB input and charge may cause the battery to overheat or reduce it's life.
Any ideas?
Thanks in advance,
Matt
as far as I know, there is a possibility of welding a 100 Ohm (or just short circuit (more risky, but I've read that some guys using a standard usb cable with simple bypassed Data-wires in combination with the S4A)) between the D+ and D+ wires of the USB-Cable (should be the green and white wire within the cable). Regarding http://www.usb.org/developers/devclass_docs a resistance below 200 ohm is the sign for a dedicated charging cable/device.
I've seen a manual of an sgs user, having full loading speed in his car, using a modified cable. Unfortunately his manual is in German, u can find it here. All credits belong to him.
by the way, i am pretty sure u will find an similar manual within this xda-board using the right search patterns, cause It does not seem to be device related.
shaDNfro,
Thank you very much for your reply, but unfortunately the 'cable mod' will not work in this instance. The reason that it won't work is that the stereo needs the Data + and Data - for Audio and synchronization data being sent back to the headunit for broadcast, and the MHL blocks the D+ and D- resistance from reaching the phone. To verify this, I took a stock Samsung cable with a voltage inverter in the car, and wired the whole system up into the MHL adapater. The system still charges at 300 ma, despite the fact that I can plug the same cable going into the MHL directly into the phone and get 1900 ma. If I use a 'modded' cable without the inverter, then the MHL still charges at 300 ma, but AppRadio will not function, as it gets no signal from the data ports on the USB. To add insult to injury, the MHL input is a 12 pin interface, and shunting D+ and D- cables on the MHL output is dangerous, as the system is doing more with the 12 pins than a standard 4 pin USB. I really don't want to fry a 400+ dollar phone.
What we really need here is one of two things:
1. The ability to upload a recompiled kernel into the system (I know that we have a bounty on this and it's not going anywhere)
2. The ability to modify the input amperage without a recompiled kernel
I'm not sure if either of the above two things can be done. I'm either going to have to live with this or get a new phone.
If ANYONE has any other ideas, please let me know!
Matt
Is it possible to mod usb cable to take the power directly from car charger?
Connect usb chargin wires to car charger from phones end of usb??
Sent from my GT-I9295 using poor english.
Vaiski said:
Is it possible to mod usb cable to take the power directly from car charger?
Connect usb chargin wires to car charger from phones end of usb??
Sent from my GT-I9295 using poor english.
Click to expand...
Click to collapse
Vaiski,
That's not a bad idea! From some more of my recent research, it appears that I now have three options I can look into:
1. Vaiski's idea of adding a 2.1 AMP second USB line to the + and - phone input while cutting the current MHL + and - cable output. This would essentially allow the MHL to get its power from the stereo's USB input, and the phone to get its power from an external, high amperage USB line and still allow me to keep the data flowing between the phone, MHL adapter, and stereo. I've got a second 'generic' MHL adapter that I wouldn't mind cutting up to spare my $50.00 Samsung MHL adapter if this doesn't work. This wouldn't allow the system to get the full 1900 ma, but it should get me upwards of 300 ma, which is where I am now.
2. I can add a wireless charger into the mix. From what I've read, if you charge with USB and wireless charging at the same time, the wireless charging would take priority. This would give me the same results as option #1.
3. I can try using the samsung S4 Multimedia dock. It appears that the dock doesn't have the same voltage output limitations as the MHL adapter. It does cost $100.00, though, and it's rather bulky.
These are all really great ideas, but what really bothers me about all this is that it shouldn't be necessary. If Samsung/AT&T hadn't installed a bootloader kernel checksum, none of this would matter. I could simply put a custom kernel in and call it a day with my current hardware. Hopefully someone will crack the bootloader soon. That would really be the best option instead of being locked into 4.2.2.
Thanks again!
Matt
s4 active charging
mattb22 said:
Vaiski,
Thanks again!
Matt
Click to expand...
Click to collapse
I don't know whether or not you found a solution to your problem yet. I discovered same problem using stock charging cable and having Bluetooth, Wi-Fi amd GPS turned on, playing music through usb to a pioneer stereo.... no Bluetooth on stereo, but was using a BT hands-free device. Anyway, same problem as you, charger wouldn't keep up. Tried turning off Wi-Fi... had mobile hotspot turned on for wife's tablet, helped some but still drained faster than charged. A couple months ago, I couldn't find the factory charging/data cable and phone needed charging, so I tried a cable from one of those battery powered phone chargers, thing is only about a foot long, but phone said "charging" it went from about 30% to full in less than an hour, this phone has never charged that fast. I've experimented with it a bit, and it won't work as a data cable but it will keep up with everything turned on. I don't know if it's the length of the cable, or if the pins on the cable are different, in any case, try different cables, if you only need charge while your driving then the lack of data won't be a problem, though I liked being able to charge and listen to music at the same time, I'd rather know that my phone won't be dead when I get to the other end of a long road trip.... besides I figured out that a flash drive plugged into stereo plays music better.
Hope this helps