5 Blinking Lights. Can't figure out what to do here.... - Nexus 7 Q&A, Help & Troubleshooting

Hey, guys and gals.
Well, I found a Nexus 7 in my car the other day and can't figure out who it belongs to. All I know is that I can't boot it up and can't charge it. All I get is 5 blinking white lights. I don't know what it means but I did some research and it seems to mean that the tablet is too dead to boot up. However, it's not accepting any charge even though I charged it overnight. All I am getting is 5 blinking lights now......before I at least got the screen turning on with an empty battery being shown. (If that makes sense)
I am not using the original charger as I don't have one and am instead using my kindle charger. Could that make a difference?
Also, there seems to be some damage around the charging port area...However, the port itself seems to be in adequate condition.
Any ideas?

If it is taking a charge it should warm up a little when it is on the charger.
No warmth == no current going in.
If the battery is so old that it is nearly dead/shorted, the tablet will get HOT when it is on the charger.
So no warmth means no battery connection, either at the USB port or at the battery connector inside the device. There are threads on here from folks who had units where the internal battery connector wasn't seated well and came loose - the teardown to that spot to seat the connector isn't too bad... search for them.
On a 2A charger it takes ~ 3-4 hrs for a 5-100% charge for a N7. That happens initially at about 1500 mA, so it is possible that the voltage on your charger simply collapses if it is only designed for say 500 MA... if that were the case no charging could occur, or only pathologically small amounts of charging could occur.
Also, the N7 has a TI charge controller chip which needs *some* small amount of juice to operate, so it is unfortunately possible for the battery voltage to get so low that the chip can't operate correctly and you get a chicken-and-egg situation where the battery can't charge, even though it is healthy - the voltage just got so low that the charging chip doesn't work. In these cases, an external charger with current limiting is needed to partly charge the tablet battery to get the voltage up high enough so it can be reconnected to the tablet and charged normally. Note that this is a 3rd scenario where you wouldn't feel any "charging warmth" even though all the connections are good.
There is a report on here of someone doing something incredibly stupid - getting some charge onto the tablet battery by disconnecting the battery connector from the tablet and directly connecting it to a car battery to charge it (That's a recipe for a battery explosion or fire). Please don't do something like that.
Something a little less stupid would be using a power resistor (e.g. 5 Watt, 30 ohms) in series with the car battery to prevent too much current from flowing. That would be safe even if the tablet battery was a dead short ( 413 mA, 5.1 Watts in the resistor ), and if the tablet battery was healthy-ish, it would trickle charge at ~ (12.4-3.0)/30 = 313 mA with 3 W dissipated in the resistor.
The important point here is that wall-wart USB chargers are designed to produce 5V up to a certain current level, but they don't actually control the amount of current; that's the job of the funky chicken-and-egg TI charging chip in the N7. So you can't just hook a 5v supply directly to the tablet battery - as you have removed the current limiting control you need something to replace that function: either something dumb to limit the current (such as a power resistor), or a slightly more advanced charger that allows you to limit the current output to a moderate maximum rate.
Note also you don't need to fully charge the battery this way; you just need to bring the charge up a few percent so it can be reconnected to the tablet and charged the "ordinary" way.
good luck

bostonbeast225 said:
Well, I found a Nexus 7 in my car the other day and can't figure out who it belongs to.
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Really? [emoji15][emoji41][emoji56]

bluebirch said:
Really? [emoji15][emoji41][emoji56]
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OP could be a cab or uber driver or something like that

Did u ever get this sorted

Related

Safe charging limit?

Looking for a "safe" range here..
I downloaded CurrentWidget to see how much current the phone is drawing while using various charging methods.
So:
- using the stock charger at home w/ a 10' usb cable (recommended from a site by many on xda) it hovers around 160 mA - charges slowly, but charges.
- using my computer w/ the stock cable it fluctuates between high-200 mA - mid-400 mA.
- using the stock charger at work w/ the stock cable it fluctuate between mid-400 mA up to high-800 mA AND the phone reaches 115-degrees from around 87-degrees in a few minutes! On top of that, it charges VERY quickly, however, sometimes, even though it says 'charging' the battery % is actually going down! As if all that power is draining the battery!
- using a car charger left over from my old, old Treo 800w, it fluctuates between mid-400 mA and mid-600 mA (temp always normal).
So my question is: what is a safe range for the current to be drawn at and why does the stock charger/usb cable seem to chaotic at times?
I don't really know much about electricity and currents and all that so if I'm using the wrong terminology, forgive me..
Thanks!
Three reasons for the current to fluctuate:
1. Current widget may not be accurate
2. Background processes may be eating some of the charge being supplied- especially radio signal fluctuations
3. The battery will resist charge as it fills causing the charge current to be reduced.
Also, HTC and many other vendors use the usb pins to determine whether you are connected to a charger that can supply sufficient power, usb is rated at only 500ma,while the charger can supply up to 1000ma.
(For reference, the ipad charges at 2A).
I don't think it's necessarily a bad thing to charge at a high rate, since its common practice. In fact, folks have reported that the battery level goes down when using google navigate without a high power charger.
Finally, the Evo has an overheat circuit that will cutoff charge if the battery gets too hot.
Sent from my PC36100 using XDA App
This is interesting. My guess on the reboot issues is that it seems similar to how a computer acts when capacitors start pooping due to heat.
I always let my phone charge 8 hours while I sleep.
If it gets up to 115 degrees and stays there for 8 hours, that could maybe cause damage???
Thanks, I'll keep that in mind. Today, it's been working fine. It's an on-and-off thing... Oh well, long as my phone doesn't start to melt I guess I'm fine.
typeadam said:
Looking for a "safe" range here..
I downloaded CurrentWidget to see how much current the phone is drawing while using various charging methods.
So:
- using the stock charger at home w/ a 10' usb cable (recommended from a site by many on xda) it hovers around 160 mA - charges slowly, but charges.
- using my computer w/ the stock cable it fluctuates between high-200 mA - mid-400 mA.
- using the stock charger at work w/ the stock cable it fluctuate between mid-400 mA up to high-800 mA AND the phone reaches 115-degrees from around 87-degrees in a few minutes! On top of that, it charges VERY quickly, however, sometimes, even though it says 'charging' the battery % is actually going down! As if all that power is draining the battery!
- using a car charger left over from my old, old Treo 800w, it fluctuates between mid-400 mA and mid-600 mA (temp always normal).
So my question is: what is a safe range for the current to be drawn at and why does the stock charger/usb cable seem to chaotic at times?
I don't really know much about electricity and currents and all that so if I'm using the wrong terminology, forgive me..
Thanks!
Click to expand...
Click to collapse
rule of thumb is to not supply the battery more than 70% rate of current of the battery's capacity. for instance, if the battery's capacity is 1000mAh, the charger should not exceed a charge rate of 700mAh.
imo, the stock charger is a tad too fast (1000mAh/1500mAh = 67%). i hardly ever use the stock charger and charge either via usb (~500mAh) or an external charger i bought on ebay rated at 800mAh. a slower charge also provides a more quality charge and will extend the charge as well as the life of the battery. the faster a battery charges, the hotter it will get. heat is the enemy with batteries.
try charging with just usb for a couple days and i guarantee you will see an increase in battery life (all other things constant of course). better yet, pick up an external charger off ebay and get even better results - even more quality charge since it is not discharging and charging at the same time. i strictly use an external charger and can hang on to 100% for over 4 hours w/o use.

USB/AC Charging Discussion

Decided to make a seperate thread for this. Maybe a mod could move those posts over...
scoob8000 said:
This is very interesting.. Gonna order one of those adaptors. I have another possible source that I'll call and see if they can get them.
Dx rocks but I lack the patience to wait for overseas shipping.
Food for thought..
I have a cheapo 4 port usb hub on my night stand for charging all my devices. It is limited to 500ma per port. Ive noticed it won't charge my atrix. Guessing 500ma isn't enough..
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Rred said:
scoob-
"It is limited to 500ma per port. Ive noticed it won't charge my atrix. Guessing 500ma isn't enough.."
No, physics doesn't work like that. If the VOLTAGE from your USB device is above the charging voltage for the phone, even a 100mA charger would be enough to charge the phone up. It would just take a long time, perhaps 22-24 hours to do so.
The normal Moto chargers are about 1000mA and they charge the phone quickly, usually two hours or less. But Moto has been making very generous chargers for years, they even supplied a 1000mA charger with my bt earpiece, which doesn't need that much power at all.
If a 500mA charger hasn't fully charged your phone in 4 hours, there's something else wrong. Bad wire, bad contact, not plugged in tight...or the "Made in China" effect.<G>
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_Dennis_ said:
No you are wrong sir. The phone will not charge on a 500 ma charge. It will use less battery but 500ma charger is not sufficient to both power the device and charge it. Also the charger supplied it 750ma charger and if you are running 1.2.6 the phone will refuse 1a chargers. Just because something provides voltage in the correct range does not mean ut provides enough energy to charge something else. Voltage is potential current is actual power. Just plug your phone into a USB socket without the computer having drivers (there by limiting the socket to 500ma) it won't charge.
Sent from my MB860 using Tapatalk
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scoob8000 said:
Sorry OP for the threadjacking..
I'm familiar with Ohm's law, where I was headed is I think the phone may be doing one of two things. (purely guessing )
It may just be adhering to USB specs. It realizes the hub is a USB device and not just a charger. Since there is no computer on the other side, to negotiate more than 100ma it just doesn't charge.
Or the voltage drop @ 500ma (my hubs max per port) is just too high to enter charging. Worth noting, is when the battery is >90 and I plug the hub in, the notification led lights, but the battery still discharges.
I need to hack up a usb cord to take some voltage/current measurements. Maybe I'm just being OCD, but I like to "slow charge" my devices while I sleep.
[edit] I think I'm going to try making a charge only USB cable... That might answer some questions
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Rred said:
Dennis?
"It will use less battery but 500ma charger is not sufficient to both power the device and charge it."
Powering the phone, and charging the phone, and simultaneously doing both, are three different things.
The 500mA is sufficient to CHARGE the phone, that's all I said. I have no idea how much power it takes to POWER the phone with all four radios (BT, GPS, Wifi, cellular) active and music or Angry Birds playing at the same time. The power drain for each of those may be significant.
But since the phone has a ~1900mAh battery, you can establish the phone's power drain by turning on "everything" and letting the battery drain from full charge. If it takes four hours to go dead...yes, the phone may consume 500mA all by itself, leaving nothing to charge the battery. Again, that's physics, and it applies the same way to every laptop and phone on the market, and other devices that use adapter/chargers.
I stand by what I said: 500mA will fully recharge the battery in about 4 hours. I did NOT say it would power all four radios and play music as well as charging the phone at the same time. You'll have to do your own math to find that out, but the physics remains the same. My phone usually charges while I sleep, and a 500mA source will do that very nicely, with just the cellular radio enabled, and not in conversation.
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Click to collapse
So I just made a little USB breakout cable so I could do a little investigation..
Oddly, even with the stock charger and the data lines disconnected the Atrix will not charge. I'm supecting most AC chargers must supply power on the data lines as well, or do something with them that triggers the device to charge.
As for the voltage, my hub and oem charger both throw out 5.12v with no load. When I plug the phone in, there is no drop at all.
From what my googling turns up, I may need a 180ish ohm resistor between the data lines. The phone looks for that to enter charging mode. Apparently this is why the drivers are needed for charging on some computers. Instead of resistance, it gets the charge signal from the pc.
So anyway out of curiosity I also took a few load readings:
Battery at 40%, screen off, phone idle: 600~ma
The most I could get it to pull was with battery at 40%, streaming last fm over a BT headset, and running quadrant. I saw around 690ma at peak.
Voice calls don't seem to make much of a difference. 10-15ma.
I'm going to check again with a full battery once it's charged. That ought to tell us what the phone itself is using.
I'm using a 550ma 5v charger because it has a longer reach. I stream music, cruise the net, watch videos and it charges my phone no problem.
Sent from my MB860 using XDA Premium App
So with a completely full battery:
Idle, screen off: 100~ma
full load (same as before): 400ma at peak
Either I am lucky and got a better one, or everyone else is wrong on the standard charger. Mine is 850ma. Also, my phone will charge on USB 2 (500ma) if screen is off and I do not use the phone. It's slow but it charges. On USB 3 it charges about half the speed it does on mains.
Sent from WinBorg 4G via XDA premium app
scoob-
"As for the voltage, my hub and oem charger both throw out 5.12v with no load."
Were you using a lab calibrated voltmeter? <G>
Most digital multimeters have a stated accuracy something like 1/2 to 1% on the DC voltages, and then they also have a "float" of 2-4 LSD meaning, the least significant digit (the rightmost one on whatever scale) may float by 2-4 digits.
So on a typical meter where you have a choice between a 2.000 volt scale, and a 20.00 volt scale, "_5.00" on the display could just as easily read "5.05" if it is was 1% off, within the limits of accuracy. And then 5.05 could read 5.09 or 5.00 as the digits float. The errors sometimes cancel out, sometimes accumulate.
I've seen much worse as they get old and out of calibration, where a "12.00" volt reading on one meter was 12.3 on another.
Which is just to say that 5.12 might actually be 5.00, or whatever the USB spec actually calls for. (It doesn't have to be 5.00 exactly.)
I had no idea they needed a signal voltage (available from the data lines on microUSB but not miniUSB) to enter charge state. That "should" mean that you can't use a miniUSB charger with a micro adapter for simple charging. I'll have to try that to see what happens. [ [LATER] Nope, something's not right about needing the signal resistor, because I just charged my Atrix using a miniUSB charger (no data signal possible) with a mini-to-micro power tip adapter, which "should" not be presenting any signal, just passing through the 4 old style connections. ]
There will still be simple--if unpublished or poorly documented--rules of physics governing what happens. Battery charging isn't rocket science, although battery chargers are sometimes "smarter" than rockets are.<G>
CaelanT,
Mines also 850ma..
Rred,
I actually splurged on a very (I think) good meter a few years ago. It's a Fluke 187. They claim .025% DC accuracy. Granted, I've had it a few years and never sent it back in for calibration.
I actually found two sides to having a resistor in the connector.
One story starts with Motorola trying to enforce people using only "genuine" chargers. Link
The other points to the data lines being shorted to indicate to the device that it is a dedicated charging device. Link Skip to the last paragraoh on this page. It's very long winded.
I actually tore apart a old car charger, in the mini usb plug there lied a small resistor between the data pins. I didn't believe how simple it was until I saw it.
Pretty interesting stuff. For us geeks anyway.
scoob, a Fluke is like a Rolls-Royce, except it is more reliable.<G>
The resistors are documented as part of the microUSB spec, they are what are often called "pull-up resistors", i.e. the voltage they provide to the fifth wire "pulls up" the voltage on that line and the tiny brains see that as a signal to do something specific.
Even the Palm Treos used this system. Not on the power line, but on the audio jack. they use a single 3-wire 2.5mm standard minijack and depending on the impedances that they see on it, they will provide mono audio, stereo audio, or mic input plus mono audio, so that three types of devices all plug into the same plug--but all three are sensed and work differently. As Arthur Clarke said "Any sufficiently advanced technology will be indistinguishable from magic."
There's no Moto conspiracy to the resistors, the new microUSB spec provides magic and the industry just doesn't want to bother our pretty little heads by talking about it in any detail.
Now, why Moto omitted the call audio routines from the library on these phones...THAT'S probably a conspiracy.<G>
I'm not reading all 480+ pages of the final USB3 spec, but it appears to refer to standard devices as consuming one "unit" of power at 150mA, with a maximum of six "units" or 900mA, and a maximum voltage of "5" which would mean that if Moto is supplying 5.12V @ 1000mA...they've exceeded the spec and aren't entitled to use the USB logo.
But if they'll fix my call audio library, I won't tell a soul about that.<VBG>

bypassing the battery and powering the device directly from the wall socket

Hi,
any way to accomplish this ? To be more clear, batteries will get a shorter life from the current work regime that I put them to, Unfortunately, the USB data cable of most phones also acts as a charger. I am using the phone for development, so this USB data cable is always attached to the phone and to the dev machine, thus forcing the battery to always charge, even at the slightest 1% discharge. It would be really good if I could take out the battery and still be able to run the phone.
Thank you!
kelogs said:
Hi,
any way to accomplish this ? To be more clear, batteries will get a shorter life from the current work regime that I put them to, Unfortunately, the USB data cable of most phones also acts as a charger. I am using the phone for development, so this USB data cable is always attached to the phone and to the dev machine, thus forcing the battery to always charge, even at the slightest 1% discharge. It would be really good if I could take out the battery and still be able to run the phone.
Thank you!
Click to expand...
Click to collapse
Depends on the phone, I know on the moto defy there was a cable mod that would bypass the battery
Sent from my GT-I9300T using xda app-developers app
adamo3957 said:
Depends on the phone, I know on the moto defy there was a cable mod that would bypass the battery
Sent from my GT-I9300T using xda app-developers app
Click to expand...
Click to collapse
That would be a Samsung Galaxy Note GT-N7000
i didn't know it is possible!
Some (most?) battery circuits are designed to deal with a dead or shorted battery.
The circuit is not arranged in a direct line between charger, battery, load.
Disconnecting a battery connector also disconnects the temperature-measuring thermistor.
With a NTC thermistor, it would think that the battery is ice cold.
A resistor of the correct value would fool it into believing it's a reasonable temperature.
I tried disconnecting the battery on my Nook and it wouldn't power up.
3,7V supply circuit as battery
You can supply the device with 3,7V (like the battery) from an external source. The only thing bad is that you have to attach wires to the gold plated battery slots on the device, or you can do it with small crocodile clips to avoid soldering. (better)
If you are ok with this, here is how you do it.
Take off your battery and measure voltage DC with a multimeter or voltmeter between battery leads. Now you know what your battery gives to the device. Example for 3 leads battery: you have 2 positive leads with the ground as reference (one slightly lower than the other) and the actual ground. So you have to supply with 3,7V the same leads that the battery was supplying. You can check while inserting the battery back to the device.
Hot to have the 3,7 Volts supply:
You will need 2 resistors, some capacitors, LM317 regulator, heat sink for that and a higher voltage DC power supply 6-12V.
Get and android device and go to play store. Install "Electrodroid" application. This will help you on sizing the LM317 regulator. Have in mind that this is programmable regulator, so you need 2 resistors to set the output voltage as 3,7V. LM317 is a linear voltage regulator, so it will act as uninterrupted 3,7 Volt battery. Be carefull to get a big heat sink, depending on the current you will be supplying and input voltage, also you can read this device datasheet online.
You can build this circuit on a breadboard if you are familiar with electronics or you can solder point to point the parts, or make a pcb if you can.
You're lucky it's N7000
full schemas are there - http://forum.xda-developers.com/showthread.php?t=1813315
PMIC's pin "_DETBAT" is connected to "VF" of battery connector. Perhaps if you pull it high it'll bootup.
And btw - usually HW is fully capable of starting off USB power. The thing is that bootloader does check if battery is present and, if not, turns off the phone. Actually this is because phone, especially during bootup, can peak to much more than 500mA current, and battery is there to compensate "missing" power.
//edit:
However, in case you don't provide any power into battery pins, it might try to charge it and U607 - Switching Charger might not really like working without load. This can generate alot of noise around AFAIK so modding kernel somehow to disable charging would be good choice.
Rebellos said:
You're lucky it's N7000
full schemas are there - http://forum.xda-developers.com/showthread.php?t=1813315
PMIC's pin "_DETBAT" is connected to "VF" of battery connector. Perhaps if you pull it high it'll bootup.
And btw - usually HW is fully capable of starting off USB power. The thing is that bootloader does check if battery is present and, if not, turns off the phone. Actually this is because phone, especially during bootup, can peak to much more than 500mA current, and battery is there to compensate "missing" power.
//edit:
However, in case you don't provide any power into battery pins, it might try to charge it and U607 - Switching Charger might not really like working without load. This can generate alot of noise around AFAIK so modding kernel somehow to disable charging would be good choice.
Click to expand...
Click to collapse
The system is powered off of Vbat - As a result, the charger MUST be active. Also, the N7000 is EASILY capable of drawing more than the maximum input current limit from Vbus, mandating extraction of power from the battery in some operating regimes.
The only way to achieve what the OP wants (total battery removal) would be with a dummy battery that had an external 4.0 volt power supply. Bad Things could happen if the device is connected to USB in this state.
However, to satisfy the OP's stated reasons for removing the battery (lots of time on USB), the likely best solution would be to disable the charging circuitry in the kernel at high states of charge. For example, one could set it up so that the charger would only be enabled when Vbat was below 4.0 volts, or when the fuel gauge SoC is below X per cent. See Ezekeel's "BLX" implementation for the Galaxy Nexus as one example of this.
thanks!
rebellos said:
you're lucky it's n7000
full schemas are there - http://forum.xda-developers.com/showthread.php?t=1813315
pmic's pin "_detbat" is connected to "vf" of battery connector. Perhaps if you pull it high it'll bootup.
And btw - usually hw is fully capable of starting off usb power. The thing is that bootloader does check if battery is present and, if not, turns off the phone. Actually this is because phone, especially during bootup, can peak to much more than 500ma current, and battery is there to compensate "missing" power.
//edit:
However, in case you don't provide any power into battery pins, it might try to charge it and u607 - switching charger might not really like working without load. This can generate alot of noise around afaik so modding kernel somehow to disable charging would be good choice.
Click to expand...
Click to collapse
thanks for the link1
Thank you all for sharing knowledge and experiences. I have made the decision to just go for some cheap ebay replacement batteries due to some advice I got from a friend, which I am sharing below:
Do not fiddle with such a fine piece of hardware (i.e. smartphone) by attaching some exposed wirings to it. The gadget could easily slip from your hands and cause the loosely hanging wirings to short-circuit upon landing on the floor. Definitely not a good perspective.
a
kelogs said:
Thank you all for sharing knowledge and experiences. I have made the decision to just go for some cheap ebay replacement batteries due to some advice I got from a friend, which I am sharing below:
Do not fiddle with such a fine piece of hardware (i.e. smartphone) by attaching some exposed wirings to it. The gadget could easily slip from your hands and cause the loosely hanging wirings to short-circuit upon landing on the floor. Definitely not a good perspective.
Click to expand...
Click to collapse
Oh give a f***ing break! It's a phone not an egg shell. And short-circuiting the wires would at worst damage the power supply not the phone.
Entropy512 said:
The system is powered off of Vbat - As a result, the charger MUST be active. .
Click to expand...
Click to collapse
This just isn't true. Modern PMIC not only have the option to stop charging the battery, but to charge the phone only on AC and also do things like send power the the USB OTG. So it is a matter of the PMIC knowing what to do. What I wish was possible was a nice app that told the PMIC to stop charging at 80% and then go to trickle mode. This would save your battery life by a lot, instead it appears to charge to 100% then back off the voltage a little.
bypass battery on unibody phone and run directly from charger
Entropy512 said:
The system is powered off of Vbat - As a result, the charger MUST be active. Also, the N7000 is EASILY capable of drawing more than the maximum input current limit from Vbus, mandating extraction of power from the battery in some operating regimes.
The only way to achieve what the OP wants (total battery removal) would be with a dummy battery that had an external 4.0 volt power supply. Bad Things could happen if the device is connected to USB in this state.
However, to satisfy the OP's stated reasons for removing the battery (lots of time on USB), the likely best solution would be to disable the charging circuitry in the kernel at high states of charge. For example, one could set it up so that the charger would only be enabled when Vbat was below 4.0 volts, or when the fuel gauge SoC is below X per cent. See Ezekeel's "BLX" implementation for the Galaxy Nexus as one example of this.
Click to expand...
Click to collapse
This would just disable the charging until the SoC dropped to the level you set though, correct? I.e. the phone is still running from the battery..? If so you still end up with more or less the same issue (although with some potential benefits depending from cycling at lower SoC).
I have a HTC One X so removing the battery and adding some circuit trickory isn't an option. But bc of this damn unibody even more motivation to run the phone directly from the charger bc I can't feed it with replacement batteries. ( which he is right thats the best options for the OP)
Anyone know if this is even possible with software mods based on the design of the phone charging system? Or any sources for literature on this. I really wanna save this battery if its the only one I got!
I am currently experimenting with this. I suppose I can only get 3 volts from the 5V input of a usb charger. Going to need to hook up to a 12v power source I suppose. Built this power supply, linear variable voltage regulator. Going to still want that data transfer. I am using diodes to make sure no power goes the wrong way into my electrolytic capacitors. I will try to post a thread if it works because I have not seen one yet.
Hello, sorry to post in an old thread, but this is the closest problem to mine that I could find.
So I'm using a 4G mi-fi modem on my PC. It's plugged in constantly 24/7 through USB cable to my PC. You can imagine the effect on the battery. I threw out 2 batteries coz they've gone bad. Sadly the modem won't turn on if it's not detecting a battery.
So I'm considering the capacitor route, just to fool the modem into thinking that a battery is installed, the real power comes from USB data cable anyway. It's a Huawei E5577, the battery got 4 terminals on it. The outermost terminals are (+) and (-), while I'm guessing the middle two are used to read the battery status (voltage, etc). So what's the simplest schematic to achieve this, using simplest capacitor circuit to fool the modem into thinking the battery is installed and working well.
Thank you

[Q] Installed Wireless QI Chrager- how do I see exactly how fast it is charging?

I just installed a QI charger for my new LG G2. I got a few QI charging pads as well. I want to see how fast it is charging, or the charge rate (500mah, 750? ect) as the receiver is supposed to do the following charge: DC 5V/500mA-1000mA .
Ive tried a few apps, but I cant find one that specifically says what the charging rate is. Anyone know the best way to figure that out?
Two questions:
1) When you say you "installed a QI charger for my new LG G2" exactly what do you mean there, and I do mean exactly: are you referring to getting a Qi charging pad (which you mention) or do you mean you got some kind of part that you physically installed in or on your G2 - the Verizon G2 is the only one that supports wireless charging out-of-the-box so, that's why I'm asking.
2) With respect to actual charging, the output of the Qi wireless charging pad is directly related to the amperage/current supplied by the actual AC adapter or USB charger you're using with it. If it's about 1A (the AC or USB charger) then you're going to lose quite a bit of power in the actual charging process because wireless charging is pretty severely inefficient most of the time, give or take you'd get 400 to 500mAh going into the actual device from the charging pad.
What I'm saying is if you have a Qi wireless charging pad, you'd be best served using as high an amperage/current charger for the pad itself so that the pad can then transfer as much as possible to the device itself. Anything less than a solid 2A charger attached to the Qi wireless charging pad and you're basically wasting a lot of it in the process and might be better off actually just using the USB port on a computer or something (about 500-550mAh max anyway).
Basic rule of thumb: the Qi wireless charging pad can use all the amperage/current it can get, with at least the factory LG 1.8A charger being what I'd call the bare minimum (and with that you'd probably be able to push about 900 to 1000 mAh (aka 1A) to the device. Qi hardware is roughly 40% efficient so, you're going to lose a lot in the process as stated; the more you start with the more that gets to the device even accounting for the inefficiency.
As far as measuring the current, you can try CurrentWidget on the Play Market, it may provide you with some info in terms of the charging rate.
br0adband said:
Two questions:
1) When you say you "installed a QI charger for my new LG G2" exactly what do you mean there, and I do mean exactly: are you referring to getting a Qi charging pad (which you mention) or do you mean you got some kind of part that you physically installed in or on your G2 - the Verizon G2 is the only one that supports wireless charging out-of-the-box so, that's why I'm asking.
2) With respect to actual charging, the output of the Qi wireless charging pad is directly related to the amperage/current supplied by the actual AC adapter or USB charger you're using with it. If it's about 1A (the AC or USB charger) then you're going to lose quite a bit of power in the actual charging process because wireless charging is pretty severely inefficient most of the time, give or take you'd get 400 to 500mAh going into the actual device from the charging pad.
What I'm saying is if you have a Qi wireless charging pad, you'd be best served using as high an amperage/current charger for the pad itself so that the pad can then transfer as much as possible to the device itself. Anything less than a solid 2A charger attached to the Qi wireless charging pad and you're basically wasting a lot of it in the process and might be better off actually just using the USB port on a computer or something (about 500-550mAh max anyway).
Basic rule of thumb: the Qi wireless charging pad can use all the amperage/current it can get, with at least the factory LG 1.8A charger being what I'd call the bare minimum (and with that you'd probably be able to push about 900 to 1000 mAh (aka 1A) to the device. Qi hardware is roughly 40% efficient so, you're going to lose a lot in the process as stated; the more you start with the more that gets to the device even accounting for the inefficiency.
As far as measuring the current, you can try CurrentWidget on the Play Market, it may provide you with some info in terms of the charging rate.
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Firstly, thank you for taking time to write such a great response. I really appreciate it!
1) Yes I installed a universal sticker. I used this one http://www.amazon.com/gp/product/B00MN3RR7Q/ which is supposedly supposed to do 1000mA. People in the reviews seem to say they are getting good results. I wish the ATT version had wireless out of the box, but then if it did I would be stuck with PMA charging. I installed an actual NFC/PMA sticker in my G3. PMA kind of sucks...anywho.
2) This is the pad I am using: http://www.amazon.com/gp/product/B00H9B7ALK/. 1.5a input and 1a output. On this one, I am averaging about 3% per 10 minutes or 30% an hour. So roughly 3 hours and 20 minutes to full charge. I can try the the stock LG. Oh, my Dell Venue 8 Pro is a 2a one. I can try that as well. Can the paid take the 2a in even though it was built for 1.5a in?
I will try current widget. Ive been using battery monitor to log as well.
1) Neat, I didn't even know such a thing existed, I may have to give that a shot with my G2 at some point (if I decide to keep it, that is).
2) As stated before, using a higher amperage/current charger or power supply is preferred, sure. It should help get the charging done faster and again the device (meaning the charger) will pull what it requires and nothing more.
Basic electronics 101 here: two things that matter with respect to smartphone chargers (or most any device, to be honest) - amperage aka current and voltage.
Voltage is pushed from a power supply meaning it will always be the same amount, give or take micro-variations. If it's a 5VDC power supply (of any kind) it's designed to provide 5VDC constantly. If it's some other value, say 9VDC, 12VDC, and so on, that's how much it pushes - if you were to connect a 9VDC charger to a smartphone or other device that's designed for a 5VDC input, you'd fry the electrical circuits in the device because it would be flooded with more power than it's designed for.
Amperage aka current is pulled from a power supply and only what is required is what's actually taken. With respect to smartphones, most of the higher end devices these days can make use of roughly 1.2 to 1.8 A (read as Amps) when it comes to charging. This means if you had a charger that output 5VDC (from what I just said above that's the standard worldwide for such devices as smartphones) but could theoretically provide 5A of current, the smartphone technically would not be damaged because it would only pull roughly 1 to 1.8 Amps at most - if you do use CurrentWidget and you plug in the G2 and look at the reading while it's charging, you'll note that the level of amperage/current being pulled from the charger fluctuates like crazy - voltage stays constant (give or take a microvolt here and there) but the current will jump all over the place, especially if you enable the "Smart Charging" feature of the G2.
The reason this happens is because when a LiIon battery is pretty low on a charge, say down to 10-15%, it's "gone deep" as the saying goes and the charging circuit will pull the max amperage/current that the charger is capable of producing and that can be measured/seen using CurrentWidget. As the battery gets into the 90% full range, the amperage/current draw will reduce (again, especially with the Smart Charging enabled) as the battery gets towards being totally full. This is a good thing in most every respect and it keeps the LiIon battery in good shape too - if it pulled the max current till it was 100% it wouldn't necessarily be so good and would heat the battery up more than necessary and LiIon batteries are very sensitive to temperature variations.
Hence, phones get fried by "cheap Chinese chargers" a lot of times because of voltage issues and faulty voltage regulators, not from amperage/current problems. It's actually kind of difficult to kill a device with amperage/current, but screwing around with the voltage will destroy a device almost 100% of the time and quite fast too.
Also, this is the reason why you'll see a phone charge relatively quickly to the 99% point then it seems to take even longer to get that last 1% to finish it off at 100% - it's the way LiIon charging technology works and helps the battery lifespan (meaning how long the battery is useful for measured in years and not "battery life" in terms of how long it can run before you have to charge it again measured in hours). The charging process "slows down" as it gets close to being full which works great for this kind of technology.
Hope this info helps...
br0adband said:
Basic rule of thumb: the Qi wireless charging pad can use all the amperage/current it can get, with at least the factory LG 1.8A charger being what I'd call the bare minimum (and with that you'd probably be able to push about 900 to 1000 mAh (aka 1A) to the device. Qi hardware is roughly 40% efficient so, you're going to lose a lot in the process as stated; the more you start with the more that gets to the device even accounting for the inefficiency.
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Okay let me see if I understand this correctly. The OUTPUT of the qi charging pad could be 1000mAh, but since the wireless QI hardware is only 40% efficient, the actual charge rate will be more around mAh to 500mAh? Im recording an actual charge rate of 500mAh and my phone states it is on AC power and not USB.
If the receiver on the phone states it can do up to 1000mAh, what I need to find is a charger that outputs a lot more like 2000mAh and at 40% efficiency I might be able to get around the 1000mAh?
That pretty much sums it up, yep - as long as you account for the inefficiency of the Qi charging technology, you can get faster charge times and still use it without having to plug in/unplug, etc the old fashioned way.
It works, it's just not nearly as fast or efficient as the old fashioned way so, give the Qi pad plenty of current and you'll be fine - since it will pull what it needs, using a 1.8A or 2A or even more won't hurt it, but it will make it pretty damned warm to the touch when it's charging so keep that in mind. As the G2 would be sitting on top of the Qi pad, if the pad gets warm or even hot then obviously the G2 will as well by heat transfer and heat/high temps are bad for LiIon batteries as I mentioned earlier.
It's a trade-off more than anything else but again, it does work as long as you're understanding the hows and whys to make the best of it.
br0adband said:
That pretty much sums it up, yep - as long as you account for the inefficiency of the Qi charging technology, you can get faster charge times and still use it without having to plug in/unplug, etc the old fashioned way.
It works, it's just not nearly as fast or efficient as the old fashioned way so, give the Qi pad plenty of current and you'll be fine - since it will pull what it needs, using a 1.8A or 2A or even more won't hurt it, but it will make it pretty damned warm to the touch when it's charging so keep that in mind. As the G2 would be sitting on top of the Qi pad, if the pad gets warm or even hot then obviously the G2 will as well by heat transfer and heat/high temps are bad for LiIon batteries as I mentioned earlier.
It's a trade-off more than anything else but again, it does work as long as you're understanding the hows and whys to make the best of it.
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I ran the battery down to 70% and I have it on the charger with a 2a wall adapter. I will see how fast it charges. But it seems like I will get roughly 1/3rd the charging speed of a wall adapter. Which means in the car using gps with the screen on and QI chrarging will probably mean a negative overall power situation.
Im also going to try a high speed, charging only cable like this http://www.amazon.com/gp/product/B009W34X5O/ between the wall adapter and the charging pad to see if there is any difference.
Don't waste your money, that thing is no better than a "Gold Plated 56K Modem Cord," seriously. Gold plating, "high speed," all that stuff is marketing BS and means absolutely nothing in the long run - it's a microUSB cable, nothing more.
In 20+ years of using USB cords of all kinds I've yet to see one that's corroded so, that gold plating is not gonna matter anyway.
Any microUSB cable you can find today is more than capable of handling ~2A without a single issue and it's well known that the G2 can max out at 1.6A draw for charging anyway so any cable is more than adequate for doing it.
br0adband said:
Don't waste your money, that thing is no better than a "Gold Plated 56K Modem Cord," seriously. Gold plating, "high speed," all that stuff is marketing BS and means absolutely nothing in the long run - it's a microUSB cable, nothing more.
In 20+ years of using USB cords of all kinds I've yet to see one that's corroded so, that gold plating is not gonna matter anyway.
Any microUSB cable you can find today is more than capable of handling ~2A without a single issue and it's well known that the G2 can max out at 1.6A draw for charging anyway so any cable is more than adequate for doing it.
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Hah! I already have one I use in the car
shaxs said:
I ran the battery down to 70% and I have it on the charger with a 2a wall adapter. I will see how fast it charges. But it seems like I will get roughly 1/3rd the charging speed of a wall adapter. Which means in the car using gps with the screen on and QI chrarging will probably mean a negative overall power situation.
Im also going to try a high speed, charging only cable like this http://www.amazon.com/gp/product/B009W34X5O/ between the wall adapter and the charging pad to see if there is any difference.
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Okay I was able to maintain neutral power with the screen on and running gps. Let it go for almost 2 hours and it was at the same percentage as when I started. Im good with that for car use.

25W charger

i heard the battery get totally broken after one year of using the original 25W charger , what is ur experiences ? does ur phone over heat too when charging does it get to 50-60 C degrees?
I've been charging mine with the turbo charger since day one, it's been fine. There is technology built in to monitor the battery temps and ramp down the charge speed as the battery gets full. I've had my phone for 16 months now.
Max temp I get is 42-44c
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same here : 15 months with my MXF the 25w turbo2 charger.
Battery never go over 45° in charge, battery life still as good as the first day
In my car I have the Moto 25w charger. With navigation and other apps running the temperature rises to about 46 degrees. At this point the charge rate drops. Only if my telephone is at the cool air and out of its cover does the charging rate remain at the full turbo charge rate
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Alimataei said:
i heard the battery get totally broken after one year of using the original 25W charger , what is ur experiences ? does ur phone over heat too when charging does it get to 50-60 C degrees?
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Not so much that the battery fails. The connector (which is kind of crucial for QC 2.0/3.0) or the charge controller craps out. Battery's fine. Was fine when I did my swap out for charge failure. It's not the battery, which people incorrectly presume is the problem- the charge system is a feedback loop process running in the background while the OS is running. When you're dead, down, no charge in the battery, the device only draws USB 2.0 power levels, 500mA, until the OS can come up enough to manage the charging. Part of the reason they do this is because you're using a USB connection to charge with and unless you've got the 1.5 A USB charge slot or an AC charger with the ability to source up to 2.4 A of juice, trying to pull that much current will wipe your USB port on a PC/Laptop/etc OUT. This is just with traditional charging. Turbo/QuickCharge charging is about raising the voltages over the USB 2.0 lines on a cable to up to 12v as opposed to 5, to allow you to jam a bit more current through the lines and to the device, effectively doubling the power being fed to the charge system. Problem with that is that you REALLY need the OS up and running to manage that. It requires info from the Charge Controller chip that is handshook from the charger.
If your charge controller is damaged, or if the cable doesn't have clean data and power lines, it just simply WON'T WORK. It will just USB mode charge until you fix the "problem"- either of which requires Lenovo to re-work the board...if it's even possible to fix. USB charging takes forever with this class of device- because the battery is a huge tank of juice compared to the devices of old. So it "looks" like the battery got "broke".
Having said this, there's about 20-40% of the units out there, depending on the crowd you listen to, that have a defective charge controller system and the phone flat-out won't ever go into any mode other than USB.

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