Develop Bugs

[Q] Rapid Chargers - Not Really Rapid?

i bought that Motorola Rapid Car charger recent and have been using it about a week now. i've noticed that it doesn't seem to charge my Thunderbolt any faster then it did when i was using the Thunderbolt's USB cable with this USB car charger adapter.
so, my question is, why is it called "rapid" if it doesn't charge any faster?
and i suppose secondly, is there an actual microUSB charger that will charge the Thunderbolt faster?
they make one for the iphone that will fully charge it in 30 minutes so i know they are out there.

voxigenboy said:
i bought that Motorola Rapid Car charger recent and have been using it about a week now. i've noticed that it doesn't seem to charge my Thunderbolt any faster then it did when i was using the Thunderbolt's USB cable with this USB car charger adapter.
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Maybe you should try this one.

Install the battery monitor widget. Monitor the battery for about 20 minutes while charging. Tell us what the charge current is.
Does the Motorola charger include a cable? If not, you may just have a weak cable. I have seen cheap cables with wire so thin that the charging current is no better then charging off a weak USB port.

My experience has been that the phone typically recognizes car charges as USB charging and uses a different charging profile. My solution to that is use a wall charger through an inverter or a kernel that doesn't use radically different charging profiles for A/C and USB.

loonatik78 said:
My experience has been that the phone typically recognizes car charges as USB charging and uses a different charging profile. My solution to that is use a wall charger through an inverter or a kernel that doesn't use radically different charging profiles for A/C and USB.
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No need for that.
Cut a small piece of aluminum foil. Carefully place it where it shorts the two center conductors in the charger. Plug the USB cable into the charger. Make sure the foil stays in place over the two center conductors.
It is now a high rate charger. (assuming it can put out 1 amp.)

The limiting factor is typically the usb cable itself. Most usb cables can't support the 1amp that is provided to it. Since you used the original usb cable that came with the thunderbolt (that's been "shorted" as mentioned above" ) it will be just as fast as the moto car charger. the 1amp charging rate that the moto charger charges at (i have one) and that the original one charges at are already "rapid". if you plugged a normal usb cable from somewhere else into the other usb car charger, it'd be much much slower

squeakyl said:
The limiting factor is typically the usb cable itself. Most usb cables can't support the 1amp that is provided to it. Since you used the original usb cable that came with the thunderbolt (that's been "shorted" as mentioned above" ) it will be just as fast as the moto car charger. the 1amp charging rate that the moto charger charges at (i have one) and that the original one charges at are already "rapid". if you plugged a normal usb cable from somewhere else into the other usb car charger, it'd be much much slower
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The stock charger is what shorts the connections. The cable is NOT shorted on the two inner pins because they are the data connections used for connecting your phone to a computer.

doodlebro said:
The stock charger is what shorts the connections. The cable is NOT shorted on the two inner pins because they are the data connections used for connecting your phone to a computer.
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To meet the USB charging spec (which the TB uses), the two inner (data) contacts should be shorted with no more that 200 ohms.
But, the cable can also be an issue for rapid charging. The voltage drop for a 1A/5V source, across only .5 M of 28 gauge copper is ~220 mV. If you use a longer cable, there's more voltage drop. The TB likely current limits itself when the voltage drops below a certain threshold. Best to buy 24 gauge USB cables, if you can, especially if getting longer ones (monoprice has them).

voxigenboy said:
i bought that Motorola Rapid Car charger recent and have been using it about a week now. i've noticed that it doesn't seem to charge my Thunderbolt any faster then it did when i was using the Thunderbolt's USB cable with this USB car charger adapter.
so, my question is, why is it called "rapid" if it doesn't charge any faster?
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I think its a matter of rated output current. BUT on the other side, the phone must be capable of drawing/using that much current. If the adapter is rated for more current than the phone can charge, the "extra" current wont be supplied.
Initially, Moto's standard car chargers output 5V and up to 550ma max (just like a standard PC USB port) so they didn't charge phones all that fast. Moto then came out with chargers that had higher current output, so they were capable of charging the phones "faster" than the original car chargers (but on par with the home/travel/AC chargers) and called them "rapid car chargers"..
Today, the current output on the Moto SPN5400A car charger is 0-950mA, and I've seen it sometimes referred to as "Rapid Car charger."
But as far as I know, Moto no longer makes/sells the lower current car chargers, and their web site only shows one MicroUSB and one MiniUSB car charger for sale, both of which appear to be of the 0-950mA output variety.
voxigenboy said:
and i suppose secondly, is there an actual microUSB charger that will charge the Thunderbolt faster?
they make one for the iphone that will fully charge it in 30 minutes so i know they are out there.
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Just because someone makes such a charger for the iPhone, doesn't mean one must exist for the TB, or other phones, does it? I know the iPad uses a 2A charger. What happens if you connect an iPhone to that? will it charge faster? I guess that depends on if the iPhone is capable of drawing more than 1A to charge it.
I've not seen a "home" or AC charger that can charge the TB any faster than the Stock 1A charger. Does such a thing exist?
A proper car charger with 950mA to 1A output should charge the TB at almost exactly the same rate as the stock 1A wall/AC charger.
And btw, the Moto SPN5400A car charger DOES charge my TB in about the same amount of time that it takes me to charge my TB at home with the stock HTC charger. So while its not "rapid" compared to the stock home/travel/AC charger, its "rapid" compared to PC USB Port charging, or a plain lower current car charger.

KidJoe said:
I've not seen a "home" or AC charger that can charge the TB any faster than the Stock 1A charger. Does such a thing exist?
A proper car charger with 950mA to 1A output should charge the TB at almost exactly the same rate as the stock 1A wall/AC charger.
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I made a charger for my motorcycle. I use it as a GPS, screen on MAX, phone active with marginal signal. And I wanted to actually charge the battery at the same time. I did a lot of experimenting with the Thunderbolt. It would not exceed a pull of about 850ma from the supply, even at 5.5 volts. IMHO, you are wasting time looking for any charger over 1 amp.
Also, even with about 850ma in, not much over 500ma is getting to the battery. So a totally dead battery is still going to take between 2 and 3 hours to charge, no matter what charger you have. And twice that long if the charger looks like a PC USB port.

worwig said:
I made a charger for my motorcycle. I use it as a GPS, screen on MAX, phone active with marginal signal. And I wanted to actually charge the battery at the same time. I did a lot of experimenting with the Thunderbolt. It would not exceed a pull of about 850ma from the supply, even at 5.5 volts. IMHO, you are wasting time looking for any charger over 1 amp.
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I was asking because of the OP's statement about knowing "they must exist" because they are out there for the iPhone.
I'm perfectly happy with my Moto car charger, and how fast it charges my phones.

Battery does not charge when the phone is in use!

Hi guys
Im having a weird problem with the battery. It seems battery doesnt charge when im using the phone although it says and shows it charging! It just stays at the same battery percentage it doesnt charge or drain! When i turn off the screen it charges the battery just fine. I called o2 UK where i bought the phone, the rep said when i use the phone it consumes more power than it gets. Can this be true?! Do you think its just a software bug or defective hardware or defective battery?
Sent from my Galaxy Nexus

This is true if you're charging from the USB on your computer. USB ports only provide 500mA. The phone seems to use more than this if you are actively using it. I recommend using a wall plug that provides at last 1 Amp (1000ma) to effectively charge the phone.

How about car chargers? Same thing happens when its charging with the car charger..
Sent from my Galaxy Nexus

If I'm not mistaken, any car charger, whether it's rated at .5A, 1A, or 2.1A is only going to provide .5A to your phone using a typical USB cable. The USB cable that came with your phone has +/- lines for power as well as 2 data lines. If you pickup a "charging only USB cable" it has the data lines shorted so that only the power lines are functional. This type of cable would allow you to take advantage of the higher current 1A and 2.1A chargers - I think anyway. I'm still new to Nexus so I haven't confirmed that, but that's the way it worked on my old phone. I did read somewhere that even with a charging only cable someone wasn't able to pull 1A from their car charger so I don't know if that was a unique issue or if the Nexus doesn't behave the same way. My understanding is the amount of current pulled from the charger is dependent on the charger AND the phone. Using a special charging cable tricks the phone into thinking it's on A/C I guess.

[Solved] Car charger suggestions

Until now, I be been using whatever cheap 1A car chargers I found on eBay. They show up as AC on the phone, and charge acceptably fast, definitely better than USB, but worse than the original AC charger.
With GPS usage (sygic, 3d acceleration, full backlight, GPS, speaker, and mild CPU usage) the battery actually drains while charging. Starting a 4 hour trip with 100% charge resulted in 40% of battery, even if it was charging on the whole duration of the trip.
So, this summer I'm going to do some bigger road trips. I need a car charger that gives enough power to charge while doing the GPS usage described above. I suppose I'm going to need a charger that gives close to actual 2A, not only in theory. Any suggestions?

kourampies said:
Until now, I be been using whatever cheap 1A car chargers I found on eBay. They show up as AC on the phone, and charge acceptably fast, definitely better than USB, but worse than the original AC charger.
With GPS usage (sygic, 3d acceleration, full backlight, GPS, speaker, and mild CPU usage) the battery actually drains while charging. Starting a 4 hour trip with 100% charge resulted in 40% of battery, even if it was charging on the whole duration of the trip.
So, this summer I'm going to do some bigger road trips. I need a car charger that gives enough power to charge while doing the GPS usage described above. I suppose I'm going to need a charger that gives close to actual 2A, not only in theory. Any suggestions?
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that is due to the fact that your phone only requests 500mA from the car charger (while your phone uses more)
are you using a custom kernel?
I use ElementalX, which has the option to enable fastcharge, which boosts it to 900mA (enough to charge with everything on)

Zorkman said:
that is due to the fact that your phone only requests 500mA from the car charger (while your phone uses more)
are you using a custom kernel?
I use ElementalX, which has the option to enable fastcharge, which boosts it to 900mA (enough to charge with everything on)
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Is there any downside to enabling fast charge. No sure if there isn't why every kernel doesn't enable it by default.

fitz420 said:
Is there any downside to enabling fast charge. No sure if there isn't why every kernel doesn't enable it by default.
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Because in theory USB ports of e.g. laptops only give 500mA. I've used it on a lot of car chargers, USB hubs, desktops and laptops and never had any problem.
Even if something were to break, it will be your car charger, because your phone can handle a lot more than 900mA, and if your car charger is rated for 1A that will suffice.

Actually the N5 stock has Fast charging enabled. The problems usually are most commonly from poor USB cables and sometimes bad chargers that don't output what they say. If you are dropping battery charge that quickly from a 1A charger most likely you have a problem with one of the 2 I mentioned above. DL CurrentWidget from the play store. Set the Update Interval to 1 sec and then plug in the charger. IF it is a 1A charger you should get just under 1A maybe about 900mA or so. Since you are losing battery life while charging and using the above things you mentioned I would imagine that it is getting about 500mA or less.
Try the test with your OEM cable from the N5 since it is more likely to be better at handling the higher current charge rate. That way you can figure if it is the cable or the charger itself.
Here are ones that MmmmmBacon suggested in his Cheap Charger thread. I am probably going to grab one myself.
http://www.amazon.com/Portable-Dual...=1399909516&sr=8-1&keywords=anker+car+charger
http://www.amazon.com/Anker®-Dual-P...=1399909109&sr=8-2&keywords=anker+car+charger

I use this and it's brilliant and actually charges the battery while using navigation -
http://www.amazon.co.uk/gp/aw/d/B00...&pf_rd_t=101&pf_rd_p=436834887&pf_rd_i=468294
Sent from my Nexus 5 using Tapatalk

Ohgami_Ichiro said:
http://www.amazon.com/Anker®-Dual-P...=1399909109&sr=8-2&keywords=anker+car+charger
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Highly recommend this. It can charge two N5s at full speed with no issue.

Sorry for the late reply... I didnt have time to even read the replies till now.
I never believed that a cable could make that much of a difference, but testing right now with the original LG AC charger and misc USB cables the difference is immence. Best performance I managed to get was from the included cable of my Anker powerbank. its around 980-1010mAh constantly, vs the 400-600 most cables do.
I will test in the car ASAP.

http://m.ebay.com/itm/301013129424
http://www.scosche.com/chargers/ipad-usb-car-charger-two-port
My combo for the most compact charging solution. Same speed as the stock charger.

http://www.amazon.com/Anker®-Du...er+car+charger
That is one of the best car chargers I've found, I use to charge my Nexus 5 when I'm on the go.

This Anker charger solved it.
It gives a steady 1000mA that is enough to charge and use GPS.
I have to give a huge thumbs up to Anker, because together with the car charger i also bought the Astroslim 3 6000mAh powerbank, which charges two devices the same time, at a steady 1500mA each!!! I loved bothe the car charger and the powerbank, definitely worth their money.

Car Tablet Install Not Charging Consistently.

As the title I'm having problems charging. A lot of the time the battery is discharging and requires being charged inside, where it does charge consistent and fast!
I the car I have a 10amp 5v dc/dc converter providing the power, I have the thick cable OTG from amazon, along with Amazon basic USB cable extensions, and a 4 port hub.
I've used different chargers, even dual chargers with a USB hub that had independent power, I changed the OTG cable, Heck I even changed TABLETS! From a Wi-Fi to an LTE. The only common thread is the backup camera and Timur's kernel.
Considering it charges perfectly plugged into a wall I assume it's not the kernel.
I've seen at least one other with this issue, Any ideas? I've been playing with this for months and as mentioned have changed every aspect of the install except the camera.

fr4nk1yn said:
As the title I'm having problems charging. A lot of the time the battery is discharging and requires being charged inside, where it does charge consistent and fast! I the car I have a 10amp 5v dc/dc converter providing the power, ...
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These car chargers supply perfect 5.0V while your original Asus AC charger delivers 5.2V (have a look at its specs). Believe it or not, 0.2V makes the difference, and at 5.0V your tablet will not charge reliably. I actually use a regulated PSU set higher, at 5.3V, to compensate for voltage drop on poor USB cables.
Look for 5.2V/2A car charger and use max 1m quality USB cable, no hubs.

Thanks. The charger is indeed 5.2v. Odd. What charger are you using?
This is the one I have: https://www.amazon.com/Converter-Re...1513386282&sr=8-8&keywords=dc+to+dc+converter and it puts out 5.1v
I found it was only getting 8v-10.5v and wired it directly to the car's wiring, I was using spades previously to connct to the Aux power connector, Getting full 14.2v made no difference to the tablet's charging.
Next I removed the tablet and plugged it into a 5v/2amp wall charger using the old OTG and the old 3 foot USB extension cable. It charges consistently between 580 - 740mA. Meanwhile it went dead installed in the dash, again.

fr4nk1yn said:
This is the one I have: https://www.amazon.com/Converter-Re...1513386282&sr=8-8&keywords=dc+to+dc+converter and it puts out 5.1v.... Meanwhile it went dead installed in the dash, again.
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To diagnose this problem you will have to acquire a simple, cheap USB meter and connect it as close as possible to N7. Note on the attachment my N7, 15cm USB cable and a tester measuring 5.18V. Please post your voltage reading.

I bought a 3amp adjustable DC to DC converter.
Set the voltage to 5.3v initially, then measured at the end of my 1 meter USB extension cable. It was still 5.3 so I dropped it back to 5.2v.
Plugged the tablet in, and it's immediately discharging at 563mAh. No apparent change after some use.

Thanks @k23m for the help. This thing just deteriorated. Something pulling a huge amount of power too. Sucked a fully charged battery to 0 in a day of of running errands. And it was sluggish beyond belief. I thought the ROM might be corrupt.
So I did the battery removal mod. It's working great on the bench so it's being wired up tomorrow. Thanks again.

Car charging issues (standard S20 5g)

So i've had this phone for a few days and took a road trip and camped this weekend. To say the least, I had a good feel of battery usage of this phone for my typical tasks.
During my road trip, my phone started with about 92% when i threw it on the charger and started driving. I noticed it was charging up to 96% and it started to discharge slowly after about an 45 minutes of driving The phone indicated it was being charged. When I purchased this phone I also purchased a 6a car charger (dual port, 3a each), and also some USB-C to USB-A cables rated at 18w. If I disconnected the power for a little bit, and reconnected, it would charge maybe 3-8% before stopping again and I would repeat the cycle to ensure I had enough battery to allow navigation to take me to my destination. Luckily, I made it to my campsite with 82% battery to spare.
Now the strange thing- when I left this morning to come back home, I had 100% on my phone as I charged it with a battery bank fine. I left the phone plugged in to my car charger as I left, and it stayed at 100%. I even let the phone discharge to 94%, and plugged it in and it was able to charge to 100% with the navigation on as well as pandora.
Am I doing something wrong? Am I supposed to be using a USB-C type charger? Maybe I need a better rated cable?
Would love some help. I'm coming from an S7 edge so a lot has changed. thanks!

liberalswine said:
When I purchased this phone I also purchased a 6a car charger (dual port, 3a each),
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I'm going to guess the charger just isn't that good, which one was it?

peachpuff said:
I'm going to guess the charger just isn't that good, which one was it?
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It's a qualcomm based charger. https://www.amazon.com/AILUN-Charger-Qualcomm-Adapter-Compatible/dp/B01N8PPY1H

Sometimes while driving these things can work loose in the lighter socket, a slight touch fumbling around near it (my dash cam does this), or some bumps in the road.
I suspect on your outbound trip the charger might have been getting intermittent power from being not quite pushed "home", but on the return trip you could have pushed it in harder and it stayed put.

yrp888 said:
Sometimes while driving these things can work loose in the lighter socket, a slight touch fumbling around near it (my dash cam does this), or some bumps in the road.
I suspect on your outbound trip the charger might have been getting intermittent power from being not quite pushed "home", but on the return trip you could have pushed it in harder and it stayed put.
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this wasn't the issue as I tried unplugging it and tried various 12v sockets in my car. However I think I did figure out my issue. The new charger i'm using does not use the "PD" protocol that the newest samsung phones use. Also, although the car charger i have is a qualcomm 3.0 protocol, and 36w- it's actually at 18w per usb A socket. The s20 wall charger is rated at 25w- so I'm now looking for a usb car charger that has a dedicated usb c socket with at least 25w of power and supports PD and pps

I'm using this one, no issues https://www.amazon.co.uk/gp/product/B07VP3HLGW/

jonboi said:
I'm using this one, no issues https://www.amazon.co.uk/gp/product/B07VP3HLGW/
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is "super fast charging" enabled with that charger? I just ordered: https://www.amazon.com/gp/product/B077ZRBPNB/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
I read somewhere that the newer samsung devices require PPM protocol in order for super fast charging rates to be active (as well as PD)

liberalswine said:
this wasn't the issue as I tried unplugging it and tried various 12v sockets in my car. However I think I did figure out my issue. The new charger i'm using does not use the "PD" protocol that the newest samsung phones use. Also, although the car charger i have is a qualcomm 3.0 protocol, and 36w- it's actually at 18w per usb A socket. The s20 wall charger is rated at 25w- so I'm now looking for a usb car charger that has a dedicated usb c socket with at least 25w of power and supports PD and pps
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I've reconsidered using fast chargers after the purchase of the S20, we've started using old 7.5W and 10W AC power adaptors. The 7.5W charger brings the phone up from about 30% to 80% in about 75min and I am fine with that. I have also used the 5W S3 charger but I think I'm happy with using the 7.5W charger.
If I need a fast boost I can always pull out the 25W charger.
I did buy a Belkin 18W PD car charger with the phone thinking "yeah, I need this" but now I will only use it for emergency charging. Tomorrow I'll pull out an old 10W car charger and plug the phone into the 10W socket while I drive around, see what happens.

Well I got into the car at 10:55 with the battery around 26%, plugged it into an old car charger I bought for our S4s (Pleomax, apparently OEM for Samsung) which has 2A & 1A outlets. It's not obvious on the charger which outlet is which but turns out I used the 1A outlet (AccuBattery showed the charging current hovering around 1000 mA).
Anyway, after 1hr of driving to my destination with a 5min break to fill up, the battery reached 66% so the 1A car charger raised the battery by 40% in about 60min, which I think is quite acceptable.
Car connected by BT for phone/SMS, received 1 call only. GPS/NFC etc are usually kept off.