car tablet power options - Connected Car

A few years ago, I installed a Verizon Samsung Tab 2 in the dash of my Cadillac. I have this tied into the sound system and use it mostly for streaming music and google maps. I had it set up so that the power (cigarette adapter) would shut off whenever the car turned off. Then I used the Tasker app to detect when the tablet was not getting power and put the tablet into Airplane mode, turn the screen off, and pause any music. This would cause it to conserve enough power that it could last a long time until I started the car again. (I cannot reach the tablet's power button once it's installed in the dash). This worked fine for years. However, this tablet was so slow due to no OS updates ever that I couldn't stand it any longer.
I recently decided to upgrade to the Verizon Asus Zenpad Z8. The issue I am now having is that no matter what I do, the tablet dies when the car is sitting. I cannot keep up with its power demands. Tasker does not have the options available to put it into airplane mode. But I have gone into the developer mode menu and set it so that the screen goes off whenever the tablet is not receiving power and it goes into super saving mode during the night. It still dies. It cannot get enough power from the cigarette adaptor to charge it fast enough to recharge what it has lost when it was parked. I have upgraded to the fastest cigarette charger I could find (3A). The battery life barely moves while the car is on, it charges soooo slowly. But the battery drains very quickly when off. This means that every time I get in the car, the tablet is off and I have to pop the panels off the dash to turn it back on.
I recently tried to use a small power inverter (powered from the cigarette adapter). This caused a massive feedback loop that was unbearable (and not fixed by an inline noise filter). I then tried a true sin wave inverter, same result. Although this did solve the power problem, it charged fast enough that there would be enough battery life that the car could sit overnight and not completely die.
I had to go back to the cig adapter. This tablet is thus far, un-rootable. That limits my options with shuttings things down and limits the features available in Tasker.
If I switch the cig adapter to power the tablet all the time, then I don't have a way to tell the tablet when to shut the screen down (so that people walking by don't see a tablet in my car and break in). I'd like some way for the tablet to know when the car is off so that it can shut things down. The easiest way to do that was by making the cig lighter turn off when the car turns off.
If anyone has any other ideas, I'm open to about anything at this point. This is getting really frustrating. Thanks.

I bought this tablet because my whole family has USB-C devices. No more stupid micro USB what an abortion that connector was. At any rate at first we used USB-A to USB-C adapter cables with USB-A charging devices. I noticed right away that most of my chargers would overheat quickly or simply charge quite slowly...the charger could not keep up with the demand if you were trying to stream video to the phone or whatever. Then I bought Google Pixel phones for me and my wife and noticed that the supplied charger has a USB-C port on it and the supplied charging cable is USB-C to USB-C. These Google supplied chargers would completely charge a dead pixel phone in 20 minutes. After reviewing the USB-C standard on Wikipedia I noticed a much higher ampacity available using USB-C to USB-C devices. So for my car I bought an LM317T integrated circuit and with a resistor and a heat sink I cobbled a little 3.5 amp 5v charging port in my dash. You could also use an LM7805 if you wanted and insert a small value resistor on the ground reference if you really want the extra .5 volts. Make sure and attach the ic to a small heat sink with heatsink compound. You will need to solder your female port to a female USB-C and use a USB-C to USB-C cable as the USB-A connector on the Asus supplied cable cannot pass enough current.

ninasmith said:
I recently decided to upgrade to the Verizon Asus Zenpad Z8. The issue I am now having is that no matter what I do, the tablet dies when the car is sitting. I cannot keep up with its power demands. Tasker does not have the options available to put it into airplane mode. But I have gone into the developer mode menu and set it so that the screen goes off whenever the tablet is not receiving power and it goes into super saving mode during the night. It still dies. It cannot get enough power from the cigarette adaptor to charge it fast enough to recharge what it has lost when it was parked. I have upgraded to the fastest cigarette charger I could find (3A). The battery life barely moves while the car is on, it charges soooo slowly. But the battery drains very quickly when off. This means that every time I get in the car, the tablet is off and I have to pop the panels off the dash to turn it back on.
I had to go back to the cig adapter. This tablet is thus far, un-rootable. That limits my options with shuttings things down and limits the features available in Tasker.
If I switch the cig adapter to power the tablet all the time, then I don't have a way to tell the tablet when to shut the screen down (so that people walking by don't see a tablet in my car and break in). I'd like some way for the tablet to know when the car is off so that it can shut things down. The easiest way to do that was by making the cig lighter turn off when the car turns off.
If anyone has any other ideas, I'm open to about anything at this point. This is getting really frustrating. Thanks.
Click to expand...
Click to collapse
Here's something you can try:
Use a different signal to trigger sleep mode, like WiFI. You could use a cheap 3G router and have the tablet connect to it via WiFi. When you exit the car take the router with you = no WiFi = tablet goes to sleep.

Related

Car charging issues

I have found that when charging my HTC phone (Kaiser now, used to be a Blue Angel) in my car, if I use a cigarette lighter splitter (So that I can charge another device too) that even if nothing else is plugged into the splitter, the phone will not charge properly. It seems to get enough power to maintain charge, but if I am low on batt, then charge the phone and use it for satnav while I drive, when I finish the journey, the phone has not charged.
This does not seem to be the case if I plug the phone charger directly into the cigarette lighter socket instead of via the splitter.
Knowing a little about electricity, I guess the splitter is running the sockets in parallel or something and dividing the power between the sockets?
Any ideas on what I could do? I would imagine a car battery has plenty of power, maybe it just isn't being distributed properly. I guess the splitter is possibly limited such that it can't pass too much power if only one device is connected?
All the devices I want to use can power from USB, so I am guessing that the solution is maybe a USB hub designed for car use. I have 3 items typically that I want to be able to charge, so a 4 port hub would be nice. Anyone know where to get one in the UK?
I've got the same issue with my car charger (HTC Mogul phone), although for me it doesn't matter whether I use a splitter. Where did you get your charger? Maybe it just isn't supplying enough power.
While it's true that having two devices in parallel causes half the current to flow to one and half to the other (assuming they have the same resistance), the power supplies should be more than capable of pushing enough current for each device, especially when the car is running (and you're getting your electricity off the alternator).
well I thought it could be a dodgy cable but I just got an official HTC car charger for my kaiser and am observing the same thing.
It could have been the cigarette lighter->USB converter or the retractible sync cable I used to use, I will do some more tests and see if I can work out which bit is causing the problem - it wasn't until just recently that I had an official end-to-end solution (ie one HTC car lighter to miniusb cable) so I will try connecting it up various ways, but it isn't exactly quick to test if it is good or not as you need your phone low on batt and to be driving around for an hour or two to see if it is charging properly.
Flat Batteries
Seems XDA has software to prevent charging batteries which are too flat. (Perhaps to protect internal circuitry).
I recommend this thread which has a solution:
http://www.htcwizardweb.net/node/2013#comment-3808
I made it work OK but it is a fiddly job. An external charger for these batteries would be great but I can't find one.
Good luck !
I have the same issue. The battery has refused to charge when its below 40% or so. I now carry a spare in the car, especially as I often depend on Sat nav working!
yeah I had that low batt thing happen with my BA once or twice.
Actually, now I have kept an eye on it, it doesn't seem that bad with my kaiser. I no longer use my car lighter usb adapter though - I use the HTC car charger into a 3-in-1 splitter (usb, extusb, 3.5mm audio) and from that into my Kaiser and it seems to charge the kaiser ok (albeit a little slowly) even when I have a cigarette lighter splitter also powering an RF transmitter.
So I think maybe the weak link was the car lighter to usb adapter, maybe it was outputting too little power on the USB rails.
Car Charger died
I'll jump on an old thread...
My HTC branded car charger (that I got from sending in the post card) worked fine for my Cingular 8525 until a few weeks ago. Then it got flakey and now it doesn't want to work at all.
My 8525 will still charge on my laptop connected cradle and the AC charger.
Has anyone seen any failures in these chargers?
Any recommendations on chargers that are reliable?
Dave.

[Q] Problems with HTC EVO car dock and charging?

Hi, everyone:
I just got the HTC EVO car dock a few weeks ago, and I'm mostly pleased with it. One strange thing, though - it appears that the phone's battery will not charge as quickly as it used to, if it charges at all.
This evening, I tried an experiment. I had my 1A charger connected to the EVO dock, then I docked my EVO. When I go into Settings/About Phone/Status, Battery status shows Charging (USB). However, when I remove my phone from the dock and plug it into the charger directly, Battery status shows Charging (AC)!
I haven't been able to find an answer to this problem. One thread here stated it is a problem with Froyo and the dock application, that it only allows charging via USB, but I can't corroborate that. I found another thread that said it's a safety feature, that it won't charge a hot battery, but in my testing above, the battery is fairly cool and I still get different results.
Has anyone else come across this problem? Perhaps it's just a defective dock? Otherwise it's a fantastic car dock, but I'd hate to find out it has a design flaw that borks charging. Thanks!
The car dock does charge as usb mainly bc the dock has a slightly different pin set putting the phone into navigation mode ..but also decreasing contact with the port ...
Sent from my PC36100 using XDA App
I have the same car charging problem, although I don't use a dock, or the docking application. I just cannot charge in the car. The EVO reports that it is charging (AC), yet no electrons flow toward the phone from the car, as reported by both Current Widget and SnapTurbo's widget.
I've been looking for a solution to this issue for a while. The car's power port works fine. I can plug the home charger into an inverter and plug the inverter into the power port and that works perfectly. I have tried three different brands of car charger and none work. My next solution will be to find a DC12 to USB adapter and use my regular USB cable and see.
Hopefully we can get some answers.
OK, a little more info:
I installed CurrentWidget, and I logged my half-hour commute. For one log, I had the phone plugged in the Dock. For the other, I had my phone plugged in directly from the charger. For both sessions, I had 3G and GPS on, Car Home was running and I had the navigation program open. Here's what I found:
Phone in Dock average draw: -77.419Ma
Phone out of Dock average draw: +136.0588Ma
So, my unscientific conclusion is that the dock is somehow losing over 200Ma. With Nav, 3G and GPS running, that's enough to change the phone from a charging state to a dis-charging state.
I guess I'm going to return this dock. It's a shame, really, because otherwise it's a well-build, easy-to-use dock. But if it's not going to charge my phone while driving, it doesn't make sense to use.
It's not the dock, its froyo...when the dock is placed into dock mode by grounding pin 4 ANY dock that truly places the phone into dock mode will do it...I built a dock cable when the phone launched, it worked fine..now after froyo it and the HTC dock cause the usb only charging rate as well as the 3.5 jack volume fix..(won't go any louder)
It is the suck. I'm the OP on the HTC dock now available thread, I've had the thing a long time and had it apart, its power and ground with a jumper to ground pin 4..that's it..no data wires..that's also why it wont let u mount the usb...also the suck...hope that helps your problem..
Sent from my PC36100 using XDA App

Hardwired car power cord stops working

Back in the day, I installed a hardwired mini-usb power cord in my car (something like this: ebay listing
It worked great for a long time powering my GPS. I haven't used it in a couple years probably though, since I use my phone for GPS now.
I'm getting the Samsung car dock for my Galaxy Nexus, so I was looking for a neat way to run power to it. I remembered this, which already comes out the dashboard. I've got a mini to micro adapter cable, so I tried it. On my nexus, it seemed to work. I was curious how much power it could provide though (and samsung phones don't let apps display the current flow) so I grabbed my old Evo 4G.
Unplugged: from 150 to 350 mA used
Plugged into the hardwired connection: around 350 mA charging. Not great, but ok. After a minute though, it changed to 350 mA LOSS. The charge light was still on and the phone still claimed to be in AC charge mode, but it was losing power.
Any ideas? Unplugging it and plugging it back in did the same thing - several hundred mA in, and then change to losing power.
My best guess is that the old charger can't really provide 1A even though it shows as an AC adapter, so it's cutting out when the phone pulls too much power. Could that be? Or is it dying? Or something else?

[Q] MHL cable not charging

So i got an MHL cable to connect my 1X to my tv to play snes games with a bluetooth controller
It works fine, plus it looks great... BUT!
The phone says it's charging.. little red light, battery info says charging, but it looses charge as i use it.
Just finished playing a snes emulator for 30 mins. I had the phone in airplane mode, plus the screen brightness on the lowest setting.
After 30 mins it went from 85% to 72%!! plus it was really warn/hot.
Is this normal? Is it because the screen is still on on the 1X?
Does the media link thingy work better? does the screen turn off on the phone when using that?
Anyone else got an MHL cable? does your phone loose charge while using it?
Under heavy use, charging in USB mode (500mA limit) will usually still see the battery level decrease. Are you putting the auxiliary charger off a USB out from your TV/console? If so this will be the case.
I have only given my MHL adapter a quick try. Not really used it in anger yet. Can't say for sure what would happen if you used a wall charger instead of a USB one. No doubt the charge wouldn't drop, but would want to keep a very close eye on the temperature!
Are you rooted?
i think the mhl adapters (mine at least) has a maximum output, to the phone, of 500ma.
This means even if you plugin a wall charger @ 1A, then it will still only provide the phone 500ma of power max.
The rest of the power goes to actually powering the cable itself, in order to get the picture on the tv.
the reason it drains, is because the consumption of the screen/cpu is greater than the 500ma of power that the mhl adapter is providing.
Thanks for the reply.
My phone is not rooted. It's just a standard out of the box 1X.
Also, when using the MHL cable the phone was plugged into the mains charger & was still loosing charge! plus it was very warm..
Maybe i'll try to find some info about those charging dock/cradle things with the HDMI out. Maybe that be better???
lawrence750 said:
i think the mhl adapters (mine at least) has a maximum output, to the phone, of 500ma.
This means even if you plugin a wall charger @ 1A, then it will still only provide the phone 500ma of power max.
The rest of the power goes to actually powering the cable itself, in order to get the picture on the tv.
the reason it drains, is because the consumption of the screen/cpu is greater than the 500ma of power that the mhl adapter is providing.
Click to expand...
Click to collapse
Ah, ok.. that makes sense really.
I did think maybe there was more power being used than coming in... shame you can't turn the screen off on the 1X.
I think you have already done the sensible thing of trying airplane mode and min screen brightness. If it still heats up doing that on USB charging, then it's unlikely a different dock/adapter would see a reduction in drain & heat. I'd save your money there.
I only asked about root in case you could try Core Control to reduce heating, but never mind there.
Only thing I found that kept my phone cool when charging under heavy use (before I rooted it), was making sure I took the case off and I rest it on a granite drinks coaster I have! Draws the heat out of the phone very efficiently!

Nexus 7 2013 (wifi) no battery mod - car install - otg - power problem

Hi there everyone,
I have been trying to get my Nexus 7 2013 installed into my car seamlessly without problems since December 2015. I have Timur's Kernel v4 (6.0.1) running on it, and it was working flawlessly.
However, I decided that the no battery mod needed to be done as I just could not leave that battery inside a hot car - way too risky.
So, I did the Kevdav no battery mod - with success.
However, once the battery connection was receiving 5v via a usb car charger the OTG cable connected to the tablet's mini usb port would not wake/suspend the tablet properly. It would wake it up, but once it was awake the little battery icon at the top would forever show that it was 'charging' and once power was cut to the otg y cable / mini usb, it would not suspend (would still show as charging).
I did research, and bought a Drok DC-DC step down converter. I lowered the voltage to the battery mod connection to 3.7v (and tested up to 4.7v) and this alleviated the problem of suspend/wake. I think since the original battery gave out less voltage then the otg/charging connection, this needed to be replicated in order for the otg to work.
However, I now have a new problem that I cannot seem to fix. This problem only seems to happen in the car and does not occur when testing it in the house using normal wall chargers.
For clarity, this is how everything is wired up in the car.
Nexus 7 battery mod side of things:
Nexus 7 battery terminals > 22awg usb cable > drok dc dc step down power supply (this board has a female usb port for output) set at 3.7v (tested up to 4.7v) > input is connected to car's constant 12v connected directly to battery on a fused wire.
Nexus 7 mini usb port side of things:
Nexus 7 mini usb port > usb otg y cable > mini usb cable > 2.4a usb car cig adapter hardwired to car's switched 12v accessory wire.
The link to the drok dc dc step down is this - https://www.amazon.co.uk/dp/B01FDBY66Y/ref=twister_B01GO268W6?_encoding=UTF8&psc=1
I turn on acc ignition to send power to the otg connection. It'll power up. However, if left in standby overnight the tablet won't power up. If I physically press the tablet's power button it'll wake up, show the wake up animation, and react as normal (including any subsequent power downs). However, if I don't press the power button and I turn off the ign again, an icon on my car's instrument cluster will be faintly illuminated - this is odd behaviour and should be completely out. When this is the case, if I get out and try to lock the car the remote central locking doesn't work.
This light will go out if I physically disconnect the otg y cable from the tablet, and low and behold the remote central locking works.
I'm no expert on electronics and such, but it seems to me that power may be flooding back into the OTG connection from the no battery mod power?
Does this make sense? Sorry for the long question, but I was wondering if anyone had any experience with troubleshooting or any advice? I've this one problem and then I'm set but I just can't seem to figure anything out and need someone's advice who is in the know rather than take wild stabs in the dark using my own logic because if I do the latter, not only will I waste money on needless components but I'll more than likely break something. I've read stuff about diodes or something in order to regulate power flow but I'm not even sure I'm using the correct terminology here so if anyone can tell me I'm onto something here or I'm talking complete nonsense then anything is appreciated!
I did search these forums and google but I really cannot find anything that is similar to my problem.
Thanks for any input guys, whether it be any tips on what I'm missing or what I need to change (software or hardware, electrical, etc) - it's all very much appreciated.
Antony
Edit: so sorry I think I posted this is the wrong n7 2013 sub section. I can't delete the post but if a mod could please kindly move it to the relevant forum I'd appreciate it. Thanks!
antc101 said:
it seems to me that power may be flooding back into the OTG connection from the no battery mod power?
Click to expand...
Click to collapse
Hi, indeed, and your "2.4a usb car cig adapter hardwired to car's switched 12v accessory wire" requires a small mod to prevent the power feedback. It needs an extra 1A+ diode connected directly to 12V input. You could modify the adapter's PCB or simply replace the fuse's internal wire with a diode where its cathode goes to the spring and its anode to 12V input. Or just place the diode somewhere along the adapter's hardwire. $0.16 1N4001 is good enough ([email protected] is OK for [email protected]).
Not sure if thread is still active but I also have the same symptom with tablet turning off completely overnight. I am running constant 12v to 3.7v dc to dc on battery input and car adapter 12v to 5v on microusb cable in. Tablet will work fine with on and off but after car is shutdown for the night it will not turn on in the morning. It shows me battery charge icon only. I dont have diode installed either. Not sure if thats the cause. Anyone know why it would completly shutdown overnight?
Neo2020Marz said:
Not sure if thread is still active but I also have the same symptom with tablet turning off completely overnight. I am running constant 12v to 3.7v dc to dc on battery input and car adapter 12v to 5v on microusb cable in. Tablet will work fine with on and off but after car is shutdown for the night it will not turn on in the morning. It shows me battery charge icon only. I dont have diode installed either. Not sure if thats the cause. Anyone know why it would completly shutdown overnight?
Click to expand...
Click to collapse
Hi there,
Been a while since I posted on this thread but just wanted to update on what I have done so far.
Since my last post, I don't have any issues. I placed a diode as mentioned above on the +12v for the accessory power. This seemed to have fixed any back flow of power.
Concerning the power off over night, I'm pretty sure this was something to do with Timur's kernel. I forever had issues with that thing - eg, suspect and wake issues, accessories connected to my usb hub..
I switched to a stock version of android 6.0.1 - MOB30X if memory serves... and installed Elemental X version 5.16. No issues with this setup what so ever.
Huh.
I run my Nexus 7 on my car with the battery, mounted just above the dashboard, with direct sunlight exposition and no UV film on the windshield. It's been a whole year without issues, thank God.
https://i.imgur.com/cPNhDDc.jpg
I live in the Northeast of Brazil, where's 30C to 40C through the year. Sometimes I come up to the car and the tablet shut off due to the heat.
Battery still lasts wonders and there's no signs of damage.. yet.
Is it really adamant to remove the battery, or is it just a precautionary measure?
GTMoraes said:
Huh.
I run my Nexus 7 on my car with the battery, mounted just above the dashboard, with direct sunlight exposition and no UV film on the windshield. It's been a whole year without issues, thank God.
https://i.imgur.com/cPNhDDc.jpg
I live in the Northeast of Brazil, where's 30C to 40C through the year. Sometimes I come up to the car and the tablet shut off due to the heat.
Battery still lasts wonders and there's no signs of damage.. yet.
Is it really adamant to remove the battery, or is it just a precautionary measure?
Click to expand...
Click to collapse
You better have more luck.
My nexus was put under the dash and was fine for around 3 years. And it became expanded in just 2 days, separating the screen and the case. So I have urgently remove the battery.

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